User's Guide for bq25570 Battery Charger Evaluation Module for
Contents
1. COUNT RefDes Value Description Size Part Number MFR 1 C1 4 7uF Capacitor Ceramic Chip 6 3V X7R 10 805 C0805C475K9RACTU Kemet 1 Go 0 01u Capacitor Ceramic 50V X7R 10 0603 GRM188R71H103KA01D Murata 1 C3 22uF Capacitor Ceramic Chip 6 3V X5R 10 805 JMK212BJ226MG T Taiyo Yuden 2 C4 C7 0 1uF Capacitor Ceramic Chip 6 3V X5R 10 603 06036D104KAT2A AVX 1 C5 4 7uF Capacitor Ceramic Chip 10V X7R 10 805 LMK212B7475KG T Taiyo Yuden 1 C6 100uF Capacitor Ceramic Chip 6 3V X5R 20 1812 GRM43SR60J107ME20L Murata 0 C8 10 DNP Capacitor Electrolytic Snap Mt vvV 7343 D n a n a 9 J1 J3 4 J6 7 J9 10 J12 13 PECO2SAAN Header Male 2 pin 100mil spacing 0 100 inch x 2 PECO2SAAN Sullins 4 J2 J5 J8 J11 ED555 2DS Terminal Block 2 pin 6 A 3 5mm 0 27 x 0 25 inch ED555 2DS OST 3 JP1 JP5 JP6 PECO2SAAN Header Male 2 pin 100mil spacing 0 100 inch x 2 PECO2SAAN Sullins 3 JP2 4 PECO3SAAN Header Male 3 pin 100mil spacing 0 100 inch x 3 PECO3SAAN Sullins L1 22uH Inductor SMT 0 65A 360milliohm 0 153 x 0 153 inch LPS4018 223M Coilcraf L2 10 uH Inductor SMT 1 4A 216milliohm 2x2 5 mm 1239AS H 100N Toko R1 7 5M Resistor Chip 1 16W 1 603 CRCW06037M50FKEA Vishay Dale R10 8 66M Resistor Chip 1 16W 1 603 CRCWO06038M66FKEA Vishay Dale R2 5 76M Resistor Chip 1 16W 1 603 CRCW06035M76FKEA Vishay Dale 2 R3 R5 4 99M Resistor Chip 1 16W 1 603 CRCW06034M99FKEA Vishay Dale R4 10M Resistor Ch2. A Not Installed Figure 1 EVM Schematic 4 User s Guide for bg25570 Battery Charger Evaluation Module for Energy Harvesting SLUUAA7 July 2013 Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com 1 5 EVM VO Connections Introduction Table 1 1 0 Connections and Configuration for Evaluation of bq25570 EVM Headers and Description Comments Recommended Setting Terminals J1 VIN Input source If VIN_DC is higher than VSTOR and VSTOR is equal to VBAT_ OV the input VIN_DC is pulled to ground J2 VINEND input source termina ook cn D te Ne ae ee J3 GND Input source return low impedance source J4 VSTOR Boost charger output Buck converter input J5 VSTOR GND Boost charger output terminal block J6 GND Boost charger return J7 VBAT Storage element connection J8 VBAT GND Storage element terminal block J9 GND Storage element connection return J10 VOUT Buck converter output J11 VOUT GND Buck converter output terminal block J12 GND Buck converter output J13 BAT OK Battery Status Indicator Test Points TP1 Input source TP2 Boost charger switching node TP3 Buck converter switching node TP4 Boost charger output TP5 Storage element connection TP6 Buck converter output TP7 VRDIV node NOTE Providing an additional low i
3. performance JP6 VBAT_OK to BAT_OK VOUT_EN configures the buck converter to be Uninstalled NOTE Do not install if JP3 shunt is installed EN enabled only when VSTOR is greater than the VBAT_OK threshold per the resistors 2 786V on the EVM 6 Users Guide for bq25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com EVM Performance Specification Summary 2 EVM Performance Specification Summary See Data Sheet Recommended Operating Conditions for component adjustments For details about the resistor programmable settings see bq25570 data sheet SLUSAHDO MIN NOM MAX UNIT Vin DC DC input voltage into VIN_DC 0 13 4 0 V Vin_start up DC DC minimum start up voltage into depleted storage element no load attached 330 mV to VSTOR or VOUT and IBAT ak lt 1uA Veat_ov Battery Over Voltage Threshold min and max values include 2 set point 4 04 4 18 4 32 V accuracy and 1 resistor tolerance but excludes effects of output ripple Vout Buck Converter Output Voltage for lour lt 95 mA min and max values 1 75 1 8 1 85 V include 2 set point regulation accuracy and 1 resistor tolerance but excludes effects of output voltage ripple line regulation and load regulation OK_HYST indication toggles high when VSTOR ramps up min and max 2 70 2 79
4. Last in priority is the boost converter inductor L1 which should be placed close to LBOOST pin 20 and VIN_DC pin 2 For the buck converter the output capacitor COUT should be placed as close as possible between VOUT pin 14 and VSS pin 15 The buck converter inductor L2 should be placed as close as possible beween the switching node LBUCK pin 16 and VOUT pin 14 It is best to use vias and bottom traces for connecting the inductors to their respective pins instead of the capacitors To minimize noise pickup by the high impedance voltage setting nodes VBAT_OV OK_PROG OK_HYST VOUT_SET the external resistors should be placed so that the traces connecting the midpoints of each divider to their respective pins are as short as possible When laying out the non power ground return paths for example from resistors and CREF it is recommended to use short traces as well separated from the power ground traces and connected to VSS pin 15 This avoids ground shift problems which can occur due to superimposition of power ground current and control ground current The PowerPad should not be used as a power ground return path The remaining pins are either NC pins that should be connected to the PowerPad as shown below or digital signals with minimal layout restrictions In order to maximize efficiency at light load the use of voltage level setting resistors gt 1MQ is recommended However during board assembly contaminants such as solder fl
5. Test Setup TIPS 22 sem saronmnnemenmemmnemneenen E a E O a e ee etienne na 7 3 2 Test Setups and ReSUItS nes Mn nn anne EE pti beads meals 8 3 3 Tips for other Tests and Measurements nent eneeeneeeteeeeeneeeeeeeeeeeeneeeneeeeenee 16 4 Bill of Materials and Board Layout sers secsneeseseeeeeeneneemneeeeeeesmeesneeee 17 4 1 Bill of Materials saisis assises sesetetenisnnnneestenouesenesnsainieteneemietesanienietemeniesedengenesenna 17 4 2 EVM Board Layout sun isetennaamanemenesnsnanententniadanatenennnaunemnannennnent 18 5 PCB Ea yout Guidelines elec cesse sement ere der ten ee 20 List of Figures 1 EVM SChEMatC wivstsidssscdncesacibictennracassennieemienadeviwsGewaaduasepeectameceddergoniheeceaa sebednemsadeeavatenduas 4 2 Test Setup for Measuring Boost Charger Efficiency e eens eee e eee eee teen eee naeeaeeeeeeee 9 3 Charger Efficiency versus Input Voltage eee e eee eeeee nese eeeeeeeeeneeeeeeeeeeeeneeeeeeeeeneeee 9 4 Charger Efficiency versus Input Current ss sssmmsensensmenmenneeenmancanntentmmnnennentenmenunntnnet 10 5 Test Setup for Measuring Buck Converter Efficiency sisi 11 6 Buck Converter Efficiency versus Output Current eee eee ee eee eee nent nee eee teense naeeeeeeeneees 11 7 Test Setup for Performing Load Transient on Buck Output sisi 12 8 50 MA Load Transient on Voisins sen ean nduanreranenn remani
6. all parameters of each component is not necessarily performed Tl assumes no liability for applications assistance or the design of Buyers products Buyers are responsible for their products and applications using TI components To minimize the risks associated with Buyers products and applications Buyers should provide adequate design and operating safeguards TI does not warrant or represent that any license either express or implied is granted under any patent right copyright mask work right or other intellectual property right relating to any combination machine or process in which TI components or services are used Information published by TI regarding third party products or services does not constitute a license to use such products or services or a warranty or endorsement thereof Use of such information may require a license from a third party under the patents or other intellectual property of the third party or a license from TI under the patents or other intellectual property of TI Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties conditions limitations and notices TI is not responsible or liable for such altered documentation Information of third parties may be subject to additional restrictions Resale of TI components or services with statements different from or beyond the par
7. and 2 this device must accept any interference including interference that may cause undesired operation of the device Concerning EVMs including detachable antennas Under Industry Canada regulations this radio transmitter may only operate using an antenna of a type and maximum or lesser gain approved for the transmitter by Industry Canada To reduce potential radio interference to other users the antenna type and its gain should be so chosen that the equivalent isotropically radiated power e i r p is not more than that necessary for successful communication This radio transmitter has been approved by Industry Canada to operate with the antenna types listed in the user guide with the maximum permissible gain and required antenna impedance for each antenna type indicated Antenna types not included in this list having a gain greater than the maximum gain indicated for that type are strictly prohibited for use with this device Cet appareil num rique de la classe A ou B est conforme a la norme NMB 003 du Canada Les changements ou les modifications pas express ment approuv s par la partie responsable de la conformit ont pu vider l autorit de l utilisateur pour actionner l quipement Concernant les EVMs avec appareils radio Le pr sent appareil est conforme aux CNR d Industrie Canada applicables aux appareils radio exempts de licence L exploitation est autoris e aux deux conditions suivantes 1 l appareil ne doit pas produi
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9. connecting any load to the EVM output If there is uncertainty as to the load specification please contact a TI field representative During normal operation some circuit components may have case temperatures greater than 60 C as long as the input and output are maintained at a normal ambient operating temperature These components include but are not limited to linear regulators switching transistors pass transistors and current sense resistors which can be identified using the EVM schematic located in the EVM User s Guide When placing measurement probes near these devices during normal operation please be aware that these devices may be very warm to the touch As with all electronic evaluation tools only qualified personnel knowledgeable in electronic measurement and diagnostics normally found in development environments should use these EVMs Agreement to Defend Indemnify and Hold Harmless You agree to defend indemnify and hold TI its licensors and their representatives harmless from and against any and all claims damages losses expenses costs and liabilities collectively Claims arising out of or in connection with any use of the EVM that is not in accordance with the terms of the agreement This obligation shall apply whether Claims arise under law of tort or contract or any other legal theory and even if the EVM fails to perform as described or expected Safety Critical or Life Critical Applications If you intend to evaluate the co
10. currently available per ambient conditions to the output The battery undervoltage VBAT_UV threshold is checked continuously to ensure that the internal battery FET connecting VSTOR to VBAT does not turn on until VSTOR is above the VBAT_UV threshold 2 0 V The over voltage VBAT_OV setting initially is lower than the programmed value at startup varies on conditions and is updated after the first 32 ms Subsequent updates are every 64 ms The VBAT_OV threshold sets maximum voltage on VSTOR and the boost converter stops switching when the voltage on VSTOR reaches the VBAT_OV threshold The open circuit input voltage VIN_OC is measured every 16 seconds in order for the Maximum Power Point Tracking MPPT circuit to sample and hold the input regulation voltage This periodic update continually optimizes maximum power delivery based on the harvesting conditions User s Guide for bg25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated l TEXAS INSTRUMENTS www ti com Introduction 1 3 1 3 1 The bq25570 was designed with the flexibility to support a variety of energy storage elements The availability of the sources from which harvesters extract their energy can often be sporadic or time varying Systems will typically need some type of energy storage element such as a re chargeable battery super capacitor or conventional ca
11. einen ai 12 9 Charger Operational Waveforms During 50 mA Load Transient 13 10 Buck Operational Waveforms During 50 mA Load Transient issus 14 11 Test Setup for Charging a Super Capacitor from Buck Output 15 12 Charging a S per Cap TOM Vi ieessshinnctwctcormcdedineedhidcickempibhivndenctnieds Gommninne see dents E seins 15 13 EVM PGB Top ASSEMBLY ess in A e tee dt Datenmege tons oem test lines 18 14 EVM PCB Top Layer is ES E EE E O Ea E E EE a eos ia 18 15 EVM PCB Bottom Layers asesi a a E EEE E E EEEE 19 List of Tables SLUUAA7 July 2013 User s Guide for bq25570 Battery Charger Evaluation Module for Energy 1 Submit Documentation Feedback Harvesting Copyright 2013 Texas Instruments Incorporated 1 1 1 2 1 TEXAS INSTRUMENTS Introduction www ti com 1 I O Connections and Configuration for Evaluation of bq25570 EVM cseceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 5 2 Billot Materials aaiossetesedeanaumaneersdaencananeedeemueneountanteueanencenuetanauacatanedueeudesens acees 17 Introduction EVM Features e Evaluation module for bq25570 e Ultra low power boost converter charger and buck converter with battery management for energy harvester applications e Resistor programmable settings for under voltage over voltage providing flexible battery management e Programmable push pull output indicator for battery status VBAT OK e Test points for key s
12. measured with a current probe 4 2V coin cell p Re wore R5 e 5 EI ee e GND JP5 Figure 7 Test Setup for Performing Load Transient on Buck Output LeCroy VSTOR 3 0V offset VOUT 1 8V otts CANAS ggg RE SASS SASSA SS VIN DC jour a cal a a o cs metase S02 500 mV chiv 100 mVidiv 50 0 mAjdiv LUE Stop 405 mA 2 000 V ofst 3 0000 V ofst 200 0 mA 10 0kS 1 0 MSis Edge Positive Figure 8 50 mA Load Transient on Voy 12 User s Guide for bg25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com 3 2 4 Test and Measurment Summary Charger Operation During Load Transient The test setup is shown in Figure 7 The specific equipment used for the test results in Figure 9 is listed below 1 2 3 VIN_DC VBAT and VOUT are configured as explained in Section 3 2 3 The boost charger inductor current IL was measured by using an oscilloscope current probe across a current loop that was inserted in series with inductor L1 VSTOR s ripple voltage was measured using an oscilloscope voltage probe placed directly across the VSTOR capacitor C5 The scope probe s standard ground lead was replaced with very s
13. of the super capacitor on VOUT instead of VBAT is faster charge time due to the charger spending less time in less efficient cold start mode SLUUAA7 July 2013 User s Guide for bq25570 Battery Charger Evaluation Module for Energy 15 Submit Documentation Feedback Harvesting Copyright 2013 Texas Instruments Incorporated TA TEXAS INSTRUMENTS Test and Measurment Summary www ti com 3 3 Tips for other Tests and Measurements The quiescent current during main boost operation which is basically the current from the battery to the IC is measured at the VSTOR pin If a source meter is not available to make the measruement connect a 100 kQ resistor to VSTOR and connect a 3 V supply from the other end of this resistor to the ground of the EVM A 10 MQ meter can be used to measure the voltage drop across the resistor and calculate the current No other connections should be made to the EVM and the measurement should be taken after steady state conditions are reached may take a few minutes The reading should be much less than 100 nA 16 User s Guide for bg25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com Bill of Materials and Board Layout 4 Bill of Materials and Board Layout 4 1 Bill of Materials Table 2 Bill of Materials
14. 2 88 V v values include 2 set point accuracy and 1 resistor tolerance ou OK_PROG indication toggles low when VSTOR ramps down min and max 2 89 2 99 3 09 V values include 2 set point accuracy and 1 resistor tolerance MPPT Maximum Power Point Tracking Resistor Programmed of Open Circuit 80 Voltage Cgar A 100 uF low leakage ceramic capacitor is installed on the EVM as the 100 uF minimum recommended equivalent battery capacitance See SLUC484 spreadsheet tool to assist with modifying the MPPT VBAT_OV VBAT_OK and VOUT resistors for your application CAUTION If changing the board resistors or the capacitor on VREF_SAMP C2 it is important to remember that residual solder flux on a board has a resistivity in the 1 20 MQ range Therefore flux remaining in parallel with changed 1 20 MQ resistors can result in a lower effective resistances which will produce different operating thresholds than expected Similarly flux remaining in parallel with the VREF_SAMP capacitor provides an additional leakage path which results in the input voltage regulation set point drooping during the 16 s MPPT cycle Therefore it is highly recommended that boards be throughly cleaned twice once after removing the old components and again after installing the new components If possible the boards should be cleaned until the wash solution measures ionic contamination greater than 50 MQ 3 Test and Measurment Summary 3 1 Test
15. Setup Tips Energy harvesting power sources are high impedance sources A source meter configured as a current source with voltage compliance set to the harvester s open circuit voltage is the best way to simulate the harvester When simulating a HiZ energy harvester with low output impedance lab power supply it is necessary to simulate the harvester s impedance with a physical resistor between the supply Vps and Vin of the EVM When the MPPT sampling circuit is active Vin Vps the harvester open circuit voltage VOC because there is no input current to create a drop across the simulated impedance that is open circuit therefore VPS should be set to the intended harvester s open circuit voltage When the boost converter is running it draws only enough current until the voltage at VIN_DC droops to the MPPT s sampled voltage that is stored at VREF_SAMP SLUUAA7 July 2013 User s Guide for bg25570 Battery Charger Evaluation Module for Energy Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 7 TA TEXAS INSTRUMENTS Test and Measurment Summary www ti com 3 2 3 2 1 The battery storage element can be replaced with a simulated battery Often electronic 4 quadrant loads give erratic results with a battery charger due to the charger changing states fast charge to termination and refresh while the electronic load is changing loads to maintain the battery voltage T
16. al device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television reception which can be determined by turning the equipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna e Increase the separation between the equipment and receiver Connect the equipment into an outlet on a circuit different from that to which the receiver is connected e Consult the dealer or an experienced radio TV technician for help For EVMs annotated as IC INDUSTRY CANADA Compliant This Class A or B digital apparatus complies with Canadian ICES 003 Changes or modifications not expressly approved by the party responsible for compliance could void the user s authority to operate the equipment Concerning EVMs including radio transmitters This device complies with Industry Canada licence exempt RSS standard s Operation is subject to the following two conditions 1 this device may not cause interference
17. ameters stated by TI for that component or service voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice TI is not responsible or liable for any such statements Buyer acknowledges and agrees that it is solely responsible for compliance with all legal regulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related information or support that may be provided by TI Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which anticipate dangerous consequences of failures monitor failures and their consequences lessen the likelihood of failures that might cause harm and take appropriate remedial actions Buyer will fully indemnify TI and its representatives against any damages arising out of the use of any TI components in safety critical applications In some cases TI components may be promoted specifically to facilitate safety related applications With such components TI s goal is to help enable customers to design and create their own end product solutions that meet applicable functional safety standards and requirements Nonetheless such components are subject to these terms No Tl components are authorized for use in FDA Class III or similar life critical medical equipment unless authorized officers of the parties have ex
18. d voltage below VBAT_OV threshold by an external source that is capable of sinking current with that sunk current being the measured output current In addition to filtering bursts of current due to PFM switching and the ripple voltage voltage on VIN_DC due to input voltage regulation the series input current meter and input voltage meter must be set to filtering or averaging or both which will result in longer than usual measurement times but not longer than the 16 s MPPT sample time Measurements for both VIN and IN will be most accurate when taken at the midpoint of the 16 s MPPT period Remote sensing by the source meters is possible but on the input side the source meter output regulation loop and the charger MPPT input regulation loop may interfere with each other and cause the input voltage to oscillate Adding a large capacitor across VIN_DC and GND will eliminate this oscillation but the capacitor s leakage current will inflate the input current measurement and lower efficiency See SLUA691 for a detailed explanation on how to take these and other measurements with source meters Buck Converter Efficiency The test setup is shown in Figure 5 The specific equipment used for the test results in Figure 6 is listed below 1 VSTOR was connected to a low impedance power supply with a series current meter to measure current The current meter must be able to measure currents in the nA range and may require manual range adjustments so tha
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20. esired output power This IC is a highly efficient charger for a storage element such as a battery or super capacitor The main difference between a battery and a super capacitor is the capacity curve The battery typically has little or no capacity below a certain voltage where as the capacitor does have capacity at lower voltages Both can have significant leakage currents that will appear as a DC load on VSTOR VBAT SLUUAA7 July 2013 User s Guide for bg25570 Battery Charger Evaluation Module for Energy 3 Submit Documentation Feedback Harvesting Copyright 2013 Texas Instruments Incorporated Introduction 1 4 EVM Schematic Figure 1 is the schematic for this EVM VSTOR TP4 VSTOR 4 99M cs 4 7uF R4 JP1 10M VOC_SAMP ae VOC_SAMP VBAT J1 4 80 35 H c6 VIN 4 99M i a 100u 0 1V 4 0V 8 m 5 V LBUCK ee Boost TP2 L1 Bs oo z d da d BQ25570RGR eno a TP1 V vss VAS vin pc BQ25570RGR S8 Jci cy VOC_SAMP VOC_SAMP 4 7uF O iuF VREF_SAMP A TP9 VREF_SAMP IPS GND 0 01uF VBAT VBAT EN GND al JP2 VSTOR Pam VSTOR V V VOUT_EN I TEXAS INSTRUMENTS www ti com VSTOR S 4 2V Adj up to 5 25V 100mA A VSTOR ca C10 GND 0 1uF J5 GND B m VBAT YV J6 27 4 2V Adj up to 5 25V TP6 VBAT J10 GND VOUT VI 38 1 8V Adj 1 3V 5 05V 50mA E J11 VOUT TPB J39 GND a GND co AT J12 aie GND V J13 BAT_OK BAT_OK gt JP6 VOUT_EN
21. h VIN_DC as low as 330 mV typ and once VSTOR reaches 1 8 V can continue to harvest energy down to VIN_DC 120 mV The integrated PFM buck converter is also powered from VSTOR and assuming enough input power is available provides up to 100 mA from the VOUT pin The VOUT voltage is externally programmed to slightly less than the VSTOR voltage HiZ DC sources have a maximum output power point MPP that varies with ambient conditions For example a solar panel s MPP varies with the amount of light on the panel and with temperature The MPP is listed by the harvesting source manufacturer as a percentage of its open circuit OC voltage Therefore the bq25570 implements a programmable maximum power point tracking MPPT sampling network to optimize the transfer of power into the device The bq25570 periodically samples the open circuit input voltage every 16 seconds by disabling the boost converter for 256 ms and stores the programmed MPP ratio of the OC voltage on the external reference capacitor C2 at VREF_SAMP Typically solar cells are at their MPP when loaded to 70 80 of their OC voltage and TEGs at 50 While the storage element is less than the user programmed maximum voltage VBAT_OV the boost converter loads the harvesting source until VIN_DC reaches the MPP voltage at VREF_SAMP This results in the boost converter regulating the input voltage of the converter until the output reaches VBAT_OV thus transferring the maximum amount of power
22. he charging and loading get out of phase and create a large signal oscillation which is due to the 4 quadrant meter A simple circuit can be used to simulate a battery and works well and can quickly be adjusted for voltage It consists of load resistor 10 Q 2 W to pull the output down to some minimum storage voltage sinking current part of battery and a lab supply connected to the BAT pin via a diode The lab supply biases up the battery voltage to the desired level It may be necessary to add more capacitance across R1 BAT T iq SR1 GND N Test Setups and Results Boost Charger Efficiency The test setup is shown in Figure 2 The specific equipment used for the test results in Figure 3 and Figure 4 is listed below 1 VIN_DC was connected to a Keithley 2420 source meter configured as a current source with voltage compliance clamp set to the open circuit voltage 2 VSTOR was connected a Keithley 2420 source meter configured as a voltage source set to the VSTOR voltage The current sunk by the source meter was the output current of the charger User s Guide for bq25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com Source Sink Meter Configured As Current Source SLUUAA7 July 2013 SM2 Source Sin
23. he data sheet Reading the data sheet first will help in understanding the operations and features of this IC In this document battery or VBAT will be used but one could substitute any appropriate storage element System Design Tips Compared to designing systems powered from an AC DC converter or large battery for example low impedance sources designing systems powered by HiZ sources requires that the system load per unit time for example per day for solar panel be compared to the expected loading per the same time unit Often there is not enough real time input harvested power for example at night for a solar panel to run the system in full operation Therefore the energy harvesting circuit collects more energy than being drawn by the system when ambient conditions allow and stores that energy in a storage element for later use to power the system See SLUC461 for an example spreadsheet on how to design a real solar panel powered system in three easy steps 1 Referring the system rail power back to VSTOR 2 Referring the required VSTOR power back to bq255xx input power 3 Computing the minimum solar panel area from the input power requirement As demonstrated in the spreadsheet for any boost converter you must perform a power balance Pour Pin Vstor x Iston Vin x In n where n is the estimated efficiency for the same or very similar configuration in order to determine the minimum input power needed to supply the d
24. hort lead VIN and the LBOOST pin switching node of the boost charger were measured by oscilloscope voltage probes connected to TP1 and TP2 LeCroy L VSTOR AC cal le LBOOST ei c4 Dam ffimebase 00s Trager 0 2 00 Vidiv 200 mViciiv 100 masi o 20 0 psidiv fStop 40 mV 6 000 Votst 200 0 mV oftst 2000mA ofst 0 10 0kS SOMSIsJEdge Postivel Figure 9 Charger Operational Waveforms During 50 mA Load Transient SLUUAA7 July 2013 User s Guide for bg25570 Battery Charger Evaluation Module for Energy 13 Submit Documentation Feedback Harvesting Copyright 2013 Texas Instruments Incorporated TA TEXAS INSTRUMENTS Test and Measurment Summary www ti com 3 2 5 Buck Converter Operation During Load Transient The test setup is shown in Figure 7 The specific equipment used for the test results in Figure 10 is listed below 1 VIN_DC VBAT and VOUT are configured as explained in Section 3 2 3 2 The buck converter inductor current IL was measured by using an oscilloscope current probe across a current loop that was inserted in series with inductor L2 3 VSTOR s ripple voltage was measured using an oscilloscope voltage probe placed directly across the VSTOR capacitor C5 VOUT s ripple voltage was measured using an oscilloscope voltage probe placed directly across the VOUT capacitor C3 Both scope probes standard ground leads were replaced with very short lead 4 The LBUCK pin s ripple voltage switching
25. ible leakage currents to minimize the risk of electrical shock hazard 3 Since the EVM is not a completed product it may not meet all applicable regulatory and safety compliance standards such as UL CSA VDE CE RoHS and WEEE which may normally be associated with similar items You assume full responsibility to determine and or assure compliance with any such standards and related certifications as may be applicable You will employ reasonable safeguards to ensure that your use of the EVM will not result in any property damage injury or death even if the EVM should fail to perform as described or expected 4 You will take care of proper disposal and recycling of the EVM s electronic components and packing materials Certain Instructions It is important to operate this EVM within Tl s recommended specifications and environmental considerations per the user guidelines Exceeding the specified EVM ratings including but not limited to input and output voltage current power and environmental ranges may cause property damage personal injury or death If there are questions concerning these ratings please contact a TI field representative prior to connecting interface electronics including input power and intended loads Any loads applied outside of the specified output range may result in unintended and or inaccurate operation and or possible permanent damage to the EVM and or interface electronics Please consult the EVM User s Guide prior to
26. ignals available for testing purpose easy probe hook up e Jumpers available easy to change settings General Description The bq25570 is an integrated energy harvesting Nano Power management solution that is well suited for meeting the special needs of ultra low power applications The product is specifically designed to efficiently acquire and manage the microwatts uW to miliwatts mW of power generated from a variety of high output impedance HiZ DC sources like photovoltaic solar or thermal electric generators or with an AC DC rectifier a piezoelectric generator The bq25570 implements a highly efficient pulse frequency modulated PFM boost converter charger targeted toward products and systems such as wireless sensor networks WSN which have stringent power and operational demands Assuming a depleted storage element has been attached the bq25570 DC DC boost converter charger that requires only microwatts of power to begin operating in cold start mode Once the boost converter output VSTOR reaches 1 8 V and can now power the converter the main boost converter can now more efficiently extract power from low voltage output harvesters such as thermoelectric generators TEGs or single and dual cell solar panels For example assuming the HiZ input source can provide at least 5 uW typical and the load on VSTOR including the storage element leakage current is less than 1 A of leakage current the boost converter can be started wit
27. ion FCC and Industry Canada IC rules For EVMs not subject to the above rules this evaluation board kit module is intended for use for ENGINEERING DEVELOPMENT DEMONSTRATION OR EVALUATION PURPOSES ONLY and is not considered by TI to be a finished end product fit for general consumer use It generates uses and can radiate radio frequency energy and has not been tested for compliance with the limits of computing devices pursuant to part 15 of FCC or ICES 003 rules which are designed to provide reasonable protection against radio frequency interference Operation of the equipment may cause interference with radio communications in which case the user at his own expense will be required to take whatever measures may be required to correct this interference General Statement for EVMs including a radio User Power Frequency Use Obligations This radio is intended for development professional use only in legally allocated frequency and power limits Any use of radio frequencies and or power availability of this EVM and its development application s must comply with local laws governing radio spectrum allocation and power limits for this evaluation module It is the user s sole responsibility to only operate this radio in legally acceptable frequency space and within legally mandated power limitations Any exceptions to this are strictly prohibited and unauthorized by Texas Instruments unless user has obtained appropriate experimental development license
28. ip 1 16W 1 603 CRCW060310MOFKEA Vishay Dale R6 887k Resistor Chip 1 16W 1 603 CRCW0603887KFKEA Vishay Dale R7 6 98M Resistor Chip 1 16W 1 603 CRCWO06036M98FKEA Vishay Dale R8 5 36M Resistor Chip 1 16W 1 603 CRCWO06035M36FKEA Vishay Dale R9 4 22M Resistor Chip 1 16W 1 603 CRCW06034M22FKEA Vishay Dale 4 TP1 TP4 6 5002 Test Point White Thru Hole Color Keyed 0 100 x 0 100 inch 5002 Keystone 0 TP2 3 TP7 DNP Test Point 0 020 Hole 0 100 x 0 100 inch STD STD 2 TP8 9 5001 Test Point Black Thru Hole Color Keyed 0 100 x 0 100 inch 5001 Keystone 1 U1 BQ25570RGR IC Ultra Low Power Harvester Charger Buck IC VQFN BQ25570RGR Tl 4 Shunt 100 mil Black 0 1 929950 00 3M 1 PCB 2 5212 in x 2 6039 in PWR206 Any SLUUAA7 July 2013 Submit Documentation Feedback User s Guide for bq25570 Battery Charger Evaluation Module for Energy Copyright 2013 Texas Instruments Incorporated Harvesting 17 Bill of Materials and Board Layout 4 2 EVM Board Layout 18 Figure 13 through Figure 15 are the board layouts for this EVM gt DOI OO Ole ND VOC_SAMP e e e 6 J9 J enen GND e GW TP8 JP4 R3 80 R4 Rs 50 LD 4p VREF_SAMP e CDE 7 Figure 14 EVM PCB Top Layer 7 VRDIV User s Guide for bq25570 Battery Charger Evaluatio
29. j TEXAS User s Guide SLUUAA7 July 2013 INSTRUMENTS User s Guide for bq25570 Battery Charger Evaluation Module for Energy Harvesting This user s guide describes the bq25570 evaluation module EVM how to perform a stand alone evaluation and how to allow the EVM to interface with the system and host The boost converter output has been configured to deliver up to 4 2 V maximum voltage to its output VSTOR using external resistors This voltage will be applied to the storage element as long as the storage element voltage at VBAT is above the internally programmed undervoltage of 2 0 V The integrated buck converter provides up to 1 8 V and 100 mA at VOUT The VBAT_OK indicator toggles high when VSTOR ramps up to 3 0 V and toggles low when VSTOR ramps down to 2 8 V Contents 1 INTTOQUCION NEED E Gemma D se eat Ge OMR ceci Rate dos ceeete 2 1 1 EVM Features s ssssenacmmemannmmseunensnanmenecentanmmenesenemdemnen sense pannes insu 2 1 2 General DESCrPUOM secisiiceetecenere setae a O EEEE EA E EE 2 1 3 Design and Evaluation Considerations eeee eee eeeeeeeeaeeeseneeeeeeeeeeeeeeeeeenaees 3 1 4 EVM SCHEMATIC cic ccnccretrsmisncisacccra saa aa a Cabin thant edeg enab acetadeiduaabmaaceactoskinamaccete 4 1 5 EVM VO CORNMECHIONS ssssssssssessnneneeseranene Dane n devenece deere ae seradat iuse neces 5 2 EVM Performance Specification Summary ss aa EEEE E 7 3 T stand M asurment SUMMARY 22 88 28 Mess e tetes eus tree denses EG 7 3 1
30. k Meter Configured As Voltage Source Test and Measurment Summary Figure 2 Test Setup for Measuring Boost Charger Efficiency 100 90 80 70 60 50 40 30 20 10 0 Efficiency Figure 3 Charger Efficiency versus Input Voltage Submit Documentation Feedback IIN 100 pA VSTOR 2 0 V VSTOR 3 0 V 0 02040608 1 VSTOR 5 5 V 12141618 2 22242628 3 Input Voltage V Copyright 2013 Texas Instruments Incorporated User s Guide for bg25570 Battery Charger Evaluation Module for Energy Harvesting 9 Test and Measurment Summary 3 2 2 10 TA TEXAS INSTRUMENTS www ti com 100 90 VIN 0 5V 80 amp 70 ay ia o i 50 40 VSTOR 1 8 V 30 VSTOR 3 0 V 20 VSTOR 5 5 V 0 01 0 1 1 10 100 Input Current mA Figure 4 Charger Efficiency versus Input Current Because the boost converter regulates input voltage instead of output voltage uses PFM switching operates at very low currents and has MPPT efficiency cannot be measured using the same test setup as for an output regulating higher power fixed frequency PWM switching boost converter The VSTOR output must be held at a fixe
31. mpedance current path in parallel with the feedback resistors for example with a 10 MO scope probe attached will degrade regulation accuracy TP8 Output return TP9 Input return Jumpers JP1 VOC_SAMP VOC_SAMP external resistors sized to configure the IC Uninstalled NOTE Do not install if JP4 shunt is installed to regulate VIN to 75 of VOC_SAMP JP2 EN EN GND enables the IC EN VSTOR disables the IC EN GND JP3 VOUT_EN VOUT_EN VSTOR enables the buck converter when VOUT_EN VSTOR NOTE Do not install if JP6 shunt is installed VSTOR is up VOUT_EN GND disables the buck converter SLUUAA7 July 2013 Submit Documentation Feedback User s Guide for bqg25570 Battery Charger Evaluation Module for Energy 5 Harvesting Copyright 2013 Texas Instruments Incorporated TA TEXAS INSTRUMENTS Introduction www ti com Table 1 1 0 Connections and Configuration for Evaluation of bq25570 EVM continued Headers and Description Comments Recommended Setting Terminals JP4 VOC_SAMP VOC_SAMP 80 configures the IC to regulate VIN to JP4 80 NOTE Do not install if JP1 shunt is installed 80 of OCV VOC_SAMP 50 configures the IC to regulate VIN to 50 of OCV JP5 VREF_SAMP to VREF_SAMP GND Uninstalled NOTE Providing an additional leakage path for the VREF_SAMP capacitor for example GND through a 10 MO scope probe attached to VREF_SAMP will degrade input voltage regulation
32. mponents for possible use in safety critical applications such as life support where a failure of the TI product would reasonably be expected to cause severe personal injury or death such as devices which are classified as FDA Class III or similar classification then you must specifically notify TI of such intent and enter into a separate Assurance and Indemnity Agreement Mailing Address Texas Instruments Post Office Box 655303 Dallas Texas 75265 Copyright 2013 Texas Instruments Incorporated IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries Tl reserve the right to make corrections enhancements improvements and other changes to its semiconductor products and services per JESD46 latest issue and to discontinue any product or service per JESD48 latest issue Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete All semiconductor products also referred to herein as components are sold subject to Tl s terms and conditions of sale supplied at the time of order acknowledgment Tl warrants performance of its components to the specifications applicable at the time of sale in accordance with the warranty in Tl s terms and conditions of sale of semiconductor products Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty Except where mandated by applicable law testing of
33. n Module for Energy Harvesting Copyright 2013 Texas Instruments Incorporated TA TEXAS INSTRUMENTS www ti com SLUUAA7 July 2013 Submit Documentation Feedback 1 TEXAS INSTRUMENTS www ti com Bill of Materials and Board Layout O OL Oo OL 00 O at 0 i D Z s C at I Figure 15 EVM PCB Bottom Layer SLUUAA7 July 2013 User s Guide for bq25570 Battery Charger Evaluation Module for Energy 19 Submit Documentation Feedback Harvesting Copyright 2013 Texas Instruments Incorporated I TEXAS INSTRUMENTS PCB Layout Guideline www ti com 5 20 PCB Layout Guideline As for all switching power supplies the PCB layout is an important step in the design especially at high peak currents and high switching frequencies If the layout is not carefully done the boost converter charger and buck converter could show stability problems as well as EMI problems Therefore use wide and short traces for the main current path and for the power ground paths The input and output Capacitors as well as the inductors should be placed as close as possible to the IC For the boost converter charger first priority are the output capacitors including the 0 1uF bypass capacitor CBYP followed by CSTOR which should be placed as close as possible between VSTOR pin 19 and VSS pin 1 Next the input capacitor CIN should be placed as close as possible between VIN_DC pin 2 and VSS pin 1
34. node of the buck converter was measured by a oscilloscope voltage probe connected to TP3 VSTOR AC VOUT AC Le dE nf eect D D SR Sd D De LBUCK HAE i Timebase 39 5 ps Trigger CGB 2 00 Vidiv 200 mVidiv 100 mayciv 20 0 psidiv Stop 620 mV 6000 Votst 2000mVotst 200 0 mA ofst I 10 0kS SOMS sfEdge Positive Figure 10 Buck Operational Waveforms During 50 mA Load Transient 14 User s Guide for bg25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com Test and Measurment Summary 3 2 6 Charging a Super Capacitor from Buck Converter Output The test setup is shown in Figure 11 The specific equipment used for the test results in Figure 12 is listed below 1 VIN_DC was connected to a Keitherly 2420 configured as a 1 0 mA current source with 1 2 V voltage compliance 2 VOUT was connected to a 120 mF super capacitor There were no other loads on VSTOR VBAT or VOUT 3 VIN_DC VSTOR and VOUT were measured with oscilloscope voltage probes connected at TP1 TP4 and TP6 Keithley 2420 IOUT 1 0 mA COMP 1 2 V PE EERE EEE ET EEEH PPP FETE ERA EEE EEE T0 0kS75 10M points Figure 12 Charging a Super Cap from Vour The benefit of charging
35. or Feasibility Evaluation Only in Laboratory Development Environments Unless otherwise indicated this EVM is not a finished electrical equipment and not intended for consumer use It is intended solely for use for preliminary feasibility evaluation in laboratory development environments by technically qualified electronics experts who are familiar with the dangers and application risks associated with handling electrical mechanical components systems and subsystems It should not be used as all or part of a finished end product Your Sole Responsibility and Risk You acknowledge represent and agree that 1 You have unique knowledge concerning Federal State and local regulatory requirements including but not limited to Food and Drug Administration regulations if applicable which relate to your products and which relate to your use and or that of your employees affiliates contractors or designees of the EVM for evaluation testing and other purposes 2 You have full and exclusive responsibility to assure the safety and compliance of your products with all such laws and other applicable regulatory requirements and also to assure the safety of any activities to be conducted by you and or your employees affiliates contractors or designees using the EVM Further you are responsible to assure that any interfaces electronic and or mechanical between the EVM and any human body are designed with suitable isolation and means to safely limit access
36. pacitor The storage element will make certain constant power is available when needed for the systems In general the storage element also allows the system to handle any peak currents that can not directly come from the input source It is important to remember that batteries and super capacitors can have significant leakage currents that need to be included with determining the loading on VSTOR To prevent damage to a customer s storage element both maximum and minimum voltages are monitored against the internally programmed under voltage VBAT_UV and user programmed over voltage VBAT_OV levels To further assist users in the strict management of their energy budgets the bq25570 toggles a user programmable battery good flag VBAT_OK checked every 64 ms to signal the microprocessor when the voltage on an energy storage element or capacitor has risen above OK_HYST threshold or dropped below OK_PROG threshold a pre set critical level To prevent the system from entering an undervoltage condition or if starting up into a depleted storage element it is highly recommended to isolate the system load from VSTOR by 1 setting VBAT_OK equal to the buck converter s enable signal VOUT_EN and 2 using an NFET to invert the BAT_OK signal so that it drives the gate of PFET which isolates the system load from VSTOR For details see the bq25570 data sheet SLUSAHO Design and Evaluation Considerations This user s guide is not a replacement for t
37. plied to VSTOR To filter bursts of current due to PFM switching the series input current meter from the VSTOR supply must be set to the highest level of filtering and or averaging which will result in longer than usual measurement times Alternatively these measurements can be taken with source meters instead of discrete power supply resistor load box and meters The source meter on VSTOR is configured as a voltage source The source meter on OUT can be configured as either a current source that sinks current i e negative current or as a voltage source with voltage at least 100 mV below the lowest expected regulation voltage point SLUUAA7 July 2013 User s Guide for bg25570 Battery Charger Evaluation Module for Energy 11 Submit Documentation Feedback Harvesting Copyright 2013 Texas Instruments Incorporated TA TEXAS INSTRUMENTS Test and Measurment Summary www ti com 3 2 3 Buck Converter Load Transient The test setup is shown in Figure 7 The specific equipment used for the test results in Figure 8 is listed below 1 VIN_DC was connected to a low impedance power supply by a series 100 Q resistor JP4 sets the MPPT voltage to 50 of VIN OC 2 VOUT was connected to a switch with a series resistor that switches in a 36 Q resistor 3 VBAT was connected a 3 2 V charged 4 2 V coin cell 4 VSTOR VOUT and VIN_DC was monitored by oscilloscope voltage scope probes attached to TP4 TP6 and TP1 respectively and GND IOUT was
38. re de brouillage et 2 l utilisateur de l appareil doit accepter tout brouillage radio lectrique subi m me si le brouillage est susceptible d en compromettre le fonctionnement Concernant les EVMs avec antennes d tachables Conform ment la r glementation d Industrie Canada le pr sent metteur radio peut fonctionner avec une antenne d un type et d un gain maximal ou inf rieur approuv pour l metteur par Industrie Canada Dans le but de r duire les risques de brouillage radio lectrique l intention des autres utilisateurs il faut choisir le type d antenne et son gain de sorte que la puissance isotrope rayonn e quivalente p i r e ne d passe pas l intensit n cessaire l tablissement d une communication satisfaisante Le pr sent metteur radio a t approuv par Industrie Canada pour fonctionner avec les types d antenne num r s dans le manuel d usage et ayant un gain admissible maximal et l imp dance requise pour chaque type d antenne Les types d antenne non inclus dans cette liste ou dont le gain est sup rieur au gain maximal indiqu sont strictement interdits pour l exploitation de l metteur Important Notice for Users of EVMs for RF Products in Japan This development kit is NOT certified as Confirming to Technical Regulations of Radio Law of Japan If you use this product in Japan you are required by Radio Law of Japan to follow the instructions below with respect to this product 1 Use this prod
39. rned within 30 days from the date of delivery for a full refund THE FOREGOING LIMITED WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES EXPRESSED IMPLIED OR STATUTORY INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES Please read the User s Guide and specifically the Warnings and Restrictions notice in the User s Guide prior to handling the product This notice contains important safety information about temperatures and voltages For additional information on TI s environmental and or safety programs please visit www ti com esh or contact TI No license is granted under any patent right or other intellectual property right of TI covering or relating to any machine process or combination in which such TI products or services might be or are used TI currently deals with a variety of customers for products and therefore our arrangement with the user is not exclusive Tl assumes no liability for applications assistance customer product design software performance or infringement of patents or services described herein REGULATORY COMPLIANCE INFORMATION As noted in the EVM User s Guide and or EVM itself this EVM and or accompanying hardware may or may not be subject to the Federal Communications Commiss
40. s from local regulatory authorities which is responsibility of user including its acceptable authorization For EVMs annotated as FCC FEDERAL COMMUNICATIONS COMMISSION Part 15 Compliant Caution This device complies with part 15 of the FCC Rules Operation is subject to the following two conditions 1 This device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation Changes or modifications not expressly approved by the party responsible for compliance could void the user s authority to operate the equipment FCC Interference Statement for Class A EVM devices This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense FCC Interference Statement for Class B EVM devices This equipment has been tested and found to comply with the limits for a Class B digit
41. t the range is always lt 10 X the expected current for best accuracy The voltage meter measures the input voltage as close to the IC VSTOR pin as possible 2 VOUT was connected to a resistor box with a series current meter to measure the current NOTE The current meter must be able to measure currents in the nA range and may require manual range adjustments so that the range is always lt 10 X the expected current for best accuracy The voltage meter measured the VOUT voltage as close to the IC VOUT pin as possible User s Guide for bg25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated 1 TEXAS INSTRUMENTS www ti com Test and Measurment Summary Figure 5 Test Setup for Measuring Buck Converter Efficiency 100 90 80 70 VOUT 1 8V T 25 C i 60 gt VSTOR 21V VSTOR 3 6V VSTOR 5 5V 0 001 0 01 0 1 1 10 100 Output Current mA Figure 6 Buck Converter Efficiency versus Output Current The buck converter is powered from VSTOR therefore to measure its efficiency alone VIN_DC should be left floating and the input power supply ap
42. uct in a shielded room or any other test facility as defined in the notification 173 issued by Ministry of Internal Affairs and Communications on March 28 2006 based on Sub section 1 1 of Article 6 of the Ministry s Rule for Enforcement of Radio Law of Japan 2 Use this product only after you obtained the license of Test Radio Station as provided in Radio Law of Japan with respect to this product or 3 Use of this product only after you obtained the Technical Regulations Conformity Certification as provided in Radio Law of Japan with respect to this product Also please do not transfer this product unless you give the same notice above to the transferee Please note that if you could not follow the instructions above you will be subject to penalties of Radio Law of Japan Texas Instruments Japan Limited address 24 1 Nishi Shinjuku 6 chome Shinjuku ku Tokyo Japan http www tij co jp CERERE LE S SOB ROMRTY hE BETRI RNE ABBA Y R RTI RAR ETT UREA ARROCPACRL TS BRABTOKH ALFOUTHAOBBEMPTULE lt K DEP SW KT OCCHRB lt KKEEW 1 ERATARA IS C BI lt FRISFSA28AMBEATA1I735 CEOSNESRBES SOMBER CCHAUEESK 2 RANAR EREKTA 3 HN S INENS C AUEE lt Za BRR RO ZERTO TORE CBEK BRACBALZURY BE BETESUEDELET ELRA TEURUE R ER OMAN A EN T EMT 2 CEkCH lt EL BAFTA CYVAYIXVYRAAH RR PMTEXAATE 6 TA24815 AHEHE http www tij co jp EVALUATION BOARD KIT MODULE EVM WARNINGS RESTRICTIONS AND DISCLAIMERS F
43. ux and even some board cleaning agents can leave residue that may form parasitic resistors across the physical resistors and or from one end of a resistor to ground especially in humid fast airflow environments This can result in the voltage regulation and threshold levels changing significantly from those expected per the installed resistor values Therefore it is highly recommended that no ground planes be poured near the voltage setting resistors In addition the boards must be carefully cleaned possibly rotated at least once during cleaning and then rinsed with de ionized water until the ionic contamination of that water is well above 50 MOhm If this is not feasible then it is recommended that the sum of the voltage setting resistors be reduced to at least 5X below the measured ionic contamination User s Guide for bg25570 Battery Charger Evaluation Module for Energy SLUUAA7 July 2013 Harvesting Submit Documentation Feedback Copyright 2013 Texas Instruments Incorporated EVALUATION BOARD KIT MODULE EVM ADDITIONAL TERMS Texas Instruments Tl provides the enclosed Evaluation Board Kit Module EVM under the following conditions The user assumes all responsibility and liability for proper and safe handling of the goods Further the user indemnifies TI from all claims arising from the handling or use of the goods Should this evaluation board kit not meet the specifications indicated in the User s Guide the board kit may be retu
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