SiC401DB, SiC402DB, SiC403DB Reference Board User`s Manual
Contents
1. 16 1 Q1 SO 8 0 30 V bball eon 2 MOSFET 0 7 4 Ri SM0603 300K 50V RES 300K Q 1 10 W 5 CRCW0603300KJNEA 78 4 R2 Smoe03 100K 50V RES 100K 0603 CRCW0603100KFKEA 79 4 R4 SM2512 TQ 200 V 10 2512 CRCW25121ROOFKEG 20 2 R5 R6 smoeos 100K 50V RES 100K 0603 CRCW0603100KFKEA ar 4 R7 SMO0603 0a 50V RES 0Q CRCW06030000Z0EA 22 1 R8 SM06003 12 4K 50V RES 12 4K 0603 CRCW060312K4FKEA 23 1 R10 smoeos 5 11K 50V RES 5 11K 0603 CRCW06035K11FKEA 24 1 R29 SM0603 TOK 50V RES 10K 50 V 0603 CRCW060310KFKED 23 1 R12 SM06003 57 6K 50V RES 57 6K 0603 CRCW060357K6FKEA 26 1 R13 SM0402 1000 50V 100R 50 V 0402 CRCW0402100RFKED 7 1 R14 SM0402 1000 50V 100R 50 V 0402 CRCW0402100RFKED 23 1 R15 SM0603 TOK 50V RES 10K 50 V 0603 CRCW060310KFKED 29 1 R23 smoeos 511K 50V RES 5 11K 0603 CRCW06035K11FKEA 3 1 R30 Smoeo3s 69 8K 50V RES 69 8K 0603 CRCW060369K8FKEA 3a l1 R39 SM0402 0a 50V OR 50 V 0402 CRCW04020000Z0ED 32 1 R51 smos0s5 3 3R 50V RES 3 3R 0805 CRCW08053R3FKEA 3 4 R52 SMo603 31 6K 50V RES 31 6K 50 V 0603 CRCW060331K6FKEA 34 U1 MLP55 32L O 0 SiC401B MicroBuck Regulator 0 35 4 BI B2 B3 B4 0 0 0 BANANA JACK 575 4 36 1 R9forSiC401 smo603 33 2K RES 33 2K Q 1 10W 1 0603 SMD CRCW060333K2FKEA 37 4 C24 smo603 820 pF CAP CER 820 pF 50 V 5 NPO 0603 C1608C0G1H821J080AA 38 1 c19 sMo603 10nF CAP CER XSA Oboi 10V 10 C0603X5R1A103K030BA 39 4 PCB SiC2. R9forSiC403 SMo603 10 7K RES 10 7K Q 1 10 W 1 0603 SMD _ CRCW060310K7FKEA 37 1 C24 for SiC403 SM0603 150 pF CAP CER 150 pF 50 V 5 NPO 0603 C1608C0G1H151J080AA 38 4 c19 smo603 10nF CAP GER H 10V 10 C0603X5R1A103K030BA 3 4 PCB iC401 2 3 Demo Board PCB Revision 22 Jan 14 9 Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 VisHAY ss _SIC401DB SiC402DB SiC403DB www vishay com Vishay Siliconix REFERENCE BOARD PHOTOS Fig 6 Top Side View Fig 7 Bottom Side View Vishay Siliconix maintains worldwide manufacturing capability Products may be manufactured at one of several qualified locations Reliability data for Silicon Technology and Package Reliability represent a composite of all qualified locations For related documents such as package tape drawings part marking and reliability data see www vishay com ppg 62923 Revision 22 Jan 14 10 Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 Mouser Electronics Authorized Distributor Click to View Pricing
3. an external 5 V for optimum efficiency and used to drive external n channel MOSFETs or other loads Additional features include cycle by cycle current limit voltage soft start under voltage protection programmable over current protection soft shutdown and selectable power save Both the SiC401A B SiC402A B and SiC403A B provides an enable input and a power good output Revision 22 Jan 14 FEATURES e SiC401 provides 15 A continuous output current capability e SiC402 provides 10 A continuous output current capability e SiC403 provides 6 A continuous output current capability e Light Load Power Save Operation SIC401A SIC402A and SiC403A minimum operating frequency fixed at 25 kHz SiC401B SiC402B and SiC403B no minimum operating frequency e Integrated bootstrap switch e Programmable 200 mA LDO with bypass logic e Temperature compensated current limit e Pseudo fixed frequency adaptive on time control e All ceramic solution enabled e Programmable input UVLO threshold e Independent enable pin for switcher and LDO e Programmable soft start and soft shutdown e 1 internal reference voltage e Power good output e Over voltage and under voltage protections e PowerCAD simulation software available at www vishay transim com login aspx e Material categorization For definitions of compliance please see www vishay com doc 99912 APPLICATIONS e Notebook desktop and server computers e Digital HDTV and digital consu
4. easily calculated from the output ripple voltage by the following formula VFB_ripple V ripple R23 R10 R23 Where Veg ripple is the ripple voltage on the feedback Vripple is the output ripple voltage R10 is the upper resistor of the feedback voltage divider R23 is the lower resistor of the feedback voltage divider Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 VIsHAY ss SIC40IDB SiC402DB SiC403DB www vishay com Vishay Siliconix SCHEMATIC OF DEMO BOARD B3_Vo B4 VO_GND P10 P1 VOUT VO_GND LI LJ 5 1K R23 R13 100 7 VoD P7 PGOOD 69 8K for SOOKHz c37 e_ 100K 10nF R2 R12 57 6K 0 1uF M3 e C28 it gt M2 e M1 e Revision 22 Jan 14 6 Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 SiC401DB SiC402DB SiC403DB Vishay Siliconix Sy VISHAY www vishay com Revision 2
5. or Volt meter can be connected to these terminals to measure or observe the output VCTRL P5 LDTRG P4 Vo enp P11 Load step control signal input Connect VCTRL and GND to a power source which supplies the correct voltage to generate the needed load step Connect LDTRG and GND to a pulse generater that drives the MOSFET which is used for transient testing EN PSV P2 This pin on the SiC401A B SiC402A B and SiC403A B have three functions continuous run is enabled by floating this pin HI enables power save PSV and grounding this pin disables switching Continuous run mode has poor light load efficiency which is typical in traditional fixed frequency switchers By enabling PSV light load efficiency is greatly improved Connecting a jumper from Vpp P1 to EN PSV P2 will pull this pin HI and PSV is enabled Tying this pin to ground disables switching ENL P6 This pin is pulled up to Vij through a 100K resistor and enables the internal adjustable LDO An external power source may be used by removing R6 and applying 5 V to P1 The IC has an internal switchover circuit which improves efficiency by tying Vout to VLDO if Vout is within 0 5 V of VLDO and disables the internal LDO The default setting is LDO enabled and VLDO is set to 5 V Detailed description can be found in the datasheet PGOOD P7 This is an open drain output and is pulled up with a 10K resistor When the voltage at the FB pin is 10 below the nominal vol
6. vishay com doc 91000 SiC401DB SiC402DB SiC403DB www vishay com Vishay Siliconix Spann nn nnn ee me AA ra rt ee PETO AT N P A Voltage 2V div Output Transient__ Voltage 50mVidiv Output Transient Current 4A div 10usjdiv Fig 2 SiC401A Transient Step Load Response in Power Saving Mode 55 Efficiency in FCM Efficiency in PSV 50 45 40 35 30 25 20 Efficiency 0 2 4 6 8 10 12 14 16 Output Current A Fig 3 SiC401A Efficiency 0 8 0 4 0 2 c e BD amp E 7 a mo oO fo l es 0 2 4 6 8 10 12 14 16 Output Current A Fig 4 SiC401A Load Regulation Revision 22 Jan 14 4 Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 Gy VISHAY www vishay com OUTPUT VOLTAGE ADJUSTMENT The evaluation board is configured for a 1 2 V output If a different output voltage is needed simply change the value of R23 based on the following formula Vo 0 6 1 R10 R23 Viippie 2 Where R10 is the upper resistor of the feedback voltage divider R23 is the lower resistor of the feedback voltage divider Viipple is the output ripp
7. 2 Jan 14 7 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 BILL of MATERIAL for SiC401A ITEM QTY REFERENCE eae VALUE VOLTAGE DESCRIPTION PART NUMBER 1 4 Ct c2 c3 c4 SM1210 22urF 16V CAP 22 pF 16 V 1210 GRM32ER71C226ME18L 2 4 C5 SM0402 O1uF 10V CAP 0 1 pF 10 V 0402 vJ0402Y104MXQCW1BC 3 4 C6 c7 Cll1 cl4 Smoso3 O01uF 50V CAP 0 1 pF 50 V 0603 VJ0603Y104KXACW1BC 4 3 C10 C20 C22 593D 68uF 20V 68 UF TAN 20 V 593D 20 593D686X0020D2TES 5 4 C12 Radial 150uF 35V Cap Radial 150 pF 35 V EU FM1V151 6 4 C13 SM0402 0 01uF 50V CAP 0 01 pF 50 V 0402 vJ0402Y103KXACW1BC 7 4 GIB Ct is smisi2 100uF 10v CAP SER eae V 20 C3216X5R1A107M160AC 8 T1 C30 SM0402 68pF 50V CAP 68 pF 50 V 0402 VJ0402Y680KXACW1BC 9 T1 C26 smos0s 4 7pF 10V 4 7 uF 10 V 0805 LMK212B7475KG T jo 1 C28 SM0402 O1pF 10V CAP 0 1 pF 10 V 0402 VJ0402Y104MXQCW1BC nla C29 SMo603 22nF 25V CAP CER 22 nF 25 V VJO603Y223KXACW1BC 2 1 C36 SM0402 560pF 50V CAP 560 pF 0402 VJ0402A561KXAPW1BC 13 1 C37 SM0402 10nF 50V CAP 10 nF 50 V 0402 OK SED ma l L1 for SiC401 IHLP4040 0 56 pH 0 56 pH IHLP4040DZERR56M01 P1 P2 P3 P4 P5 15 11 P6 P7 P8 P9 Terminal 0 0 Test points 1573 3 P10 P11
8. 401 2 3 Demo Board PCB Document Number 62923 SiC401DB SiC402DB SiC403DB Vishay Siliconix ayy VISHAY www vishay com BILL of MATERIAL for SiC402A ITEM QTY REFERENCE egorpaint VALUE VOLTAGE DESCRIPTION PART NUMBER 1 4 C1 C2 c3 c4 Smi2i0 22urF 16V CAP 22 pF 16 V 1210 GRM32ER71C226ME18L 2 4 C5 smo402 0 1pF 10V CAP 0 1 pF 10 V 0402 VJ0402Y104MXQCW1BC 3 4 C6 C7 C11 c14 SM0603 01pF 50V CAP 0 1 pF 50 V 0603 VJ0603Y104KXACW1BC 4 3 C10 C20 C22 593D 68pF 20V 68 UF TAN 20 V 593D 20 593D686X0020D2TE3 5 4 C12 Radial 150pF 35V CAP Radial 150 pF 35 V EU FM1V151 6 1 C13 Sm0402 0 01pF 50V CAP 0 01 pF 50 V 0402 VJ0402103KXACW1BC 7 3 ae Joo SM1206 100pF 10V CAP PE le C3216X5R1A107M160AG 8 4 C30 SM0402 68pF 50V CAP 68 pF 50 V 0402 VJ0402Y680KXACW1BC 9 4 C26 SM0805 47pF 10V 4 7 uF 10 V 0805 LMK212B7475KG T to 4 C28 Smo402 0 1pF 10V CAP 0 1 pF 10 V 0402 VJ0402Y104MXQCW1BC mli C29 SM0603 22nF 25V CAP CER 22 nF 25 V VJ0603Y223KXACW1BC 2l C36 Smo402 560pF 50V CAP 560 pF 0402 VJ0402A561KXAPW1BC 13 1 C37 smo4o2 10nF 50V CAP 10 nF 50 V 0402 Sede ee ae 4 4 Li IHLP4040 1 pH 0 THH IHLP4040DZER1ROMO1 P1 P2 P3 P4 15 11 P5 P6 P7 P8 Terminal 0 0 Test points 1573 3 P9 P10 P11 w m Pap P au N Channe
9. 60pF 0402 VJ0402A561KXAPW1BC 13 1 C37 smo4o2 1onF 50V CAP 10 nF 50 V 0402 eee er ae 14 1 Ltforsicao3 IHLP2525 15pH 0 1 5 pH IHLP2525CZER1R5M01 P1 P2 P3 P4 15 11 P5 P6 P7 P8 Terminal 0 0 Test points 1573 3 P9 P10 P11 ey ai ee i ae N Channel 30 V pS MOSFET with i 7 Ri smoe03 300K 50V RES 300K Q 1 10 W 5 CRCWO603300KJNEA 8 4 R2 SM0603 100K 50V RES 100K 0603 CRCW0603100KFKEA 79 4 R4 SM2512 10 200V 10 2512 CRCW25121ROOFKEG 20 2 R5 R6 smoe03 100K 50V RES 100K 0603 CRCW0603100KFKEA a R7 sMmo603 02 50V RES 0 CRCWO06030000Z0EA 22 4 R8 smoe03 10K 50V RES 10K 50 V 0603 CRCW060310KFKED 23 4 R10 SM0402 511K 50V RES 5 11K 0402 CRCW04025K11FKED 24 R29 smoe03 10K 50V RES 10K 50 V 0603 CRCW060310KFKED 25 R12 Smo603 57 6K 50V RES 57 6K 0603 CRCW060357K6FKEA 2 1 R13 SM00402 1009 50V 100R 50 V 0402 CRCW0402100RFKED 27 R14 smo402 1009 50V 100R 50 V 0402 CRCW0402100RFKED 2 R15 sMo603 10K 50V RES 10K 50 V 0603 CRCW060310KFKED 2 1 R23 SM0402 511K 50V RES 5 11K 0402 CRCW04025K11FKED 30 R30 Smo603 69 8K 50V RES 69 8K 0603 CRCWO060369K8FKEA 31 4 R39 smo402_ 02 50V OR 50 V 0402 CRCW04020000Z0ED 32 4 R51 smos05 33R 50V RES 3 3R 0805 CRCWO08053R3FKEA 33 4 R52 Smo603 31 6K 50V RES 31 6K 50 V 0603 CRCW060331K6FKEA 34 4 U1 MLP55 32L 0 SiC403B MicroBuck Regulator 0 35 4 Bi B2 B3 B4 0 0 BANANA JACK 575 4 36 1
10. Inventory Delivery amp Lifecycle Information Vishay SIC401DB SIC403DB SIC402DB
11. ay VISHAY www vishay com SiC401DB SiC402DB SiC403DB Vishay Siliconix Reference Board User s Manual THE CHIP PRODUCT SUMMARY SiC401A B Input Voltage Range 3Vto17V Output Voltage Range 0 6 V to 5 5 V Operating Frequency 200 kHz to 1 MHz Continuous Output Current 15A Peak Efficiency 95 Package PowerPAK MLP55 32L PRODUCT SUMMARY SiC402A B Input Voltage Range 3V to 28V Output Voltage Range 0 6 V to 5 5 V Operating Frequency 200 kHz to 1 MHz Continuous Output Current 10A Peak Efficiency 95 Package PowerPAK MLP55 32L PRODUCT SUMMARY SiC403A B Input Voltage Range 3V to 28 V Output Voltage Range 0 6 V to 5 5 V Operating Frequency 200 kHz to 1 MHz Continuous Output Current 6A Peak Efficiency 95 Package PowerPAK MLP55 32L DESCRIPTION The Vishay Siliconix SiC401A B SiC402A B and SiC403A B are advanced stand alone synchronous buck regulators featuring integrated power MOSFETs bootstrap switch and a programmable LDO in a space saving PowerPAK MLP55 32L pin packages The SiC401A B SiC402A B and SiC403A B are capable of operating with all ceramic solutions and switching frequencies up to 1 MHz The programmable frequency synchronous operation and selectable power save feature allow operation at high efficiency across the full range of load current The internal LDO may be used to supply 5 V for the gate drive circuits or it may be bypassed with
12. e voltage injection circuit consisting of 3 inexpensive passive components R9 C19 and C24 is needed The network is a series RC connected across the output inductor and a cap which couples this signal to the FB pin The objective is to stabilize the IC by increasing the ripple at the FB pin by summing the ripple generated by this ESR circuit with the low ripple generated by the ceramic output capacitors Using the following formula and the circuit below we can get approximate values For example L1 1 uH DCR of inductor 3 5 mQ Let R1 3K solving for C1 we get L1 DCR R9 C19 C19 1 pH 3 5 mQ 3K 95 nF 0 1 YF Revision 22 Jan 14 5 SiC401DB SiC402DB SiC403DB Vishay Siliconix Decreasing R9 will allow more signal through hence more ripple will be seen at the FB pin Be sure to check that the signal from the virtual ESR circuit is in phase with the output ripple C24 is a 0 1 uF capacitor Fig 5 Ripple Voltage Injection Circuit Before adding a ripple injection circuit the ripple voltage in the feedback of the device need to be determined first to make sure the ripple voltage is lower than 20 mV The ripple injection circuit is required only when the ripple voltage in the feedback is lower than 20 mV There may be difficulty measuring the ripple voltage of feedback pin on the demo board However it is recommended to measure the ripple voltage on the output voltage Vo The ripple voltage on the feedback can be
13. fied e Since the internal LDO is set to 5 V it is used to drive the Vpp input on the reference board Input voltages lower then 5 V require an external 5 V supply and should be connected to Vpp to bias the internal drivers and logic Since an external source is used the internal LDO should be disabled by removing R6 Efficiency is expected to be improved since the internal LDO is not used INPUT CAPACITORS The input capacitors are chosen as a combination of electrolytic and ceramics so that the capacitance the RMS current the ESR the input voltage ripple and the cost can be all fairly satisfied For a combination of high voltage input and low voltage output low duty cycle the electrolytic capacitor C12 may not be required The reference board uses 25 V input ceramics therefore please limit Vin to 25 V or less INDUCTORS If off the shelf inductors are to be used then their DCR and saturation current parameters are key besides the inductance values The DCR causes an I R loss which will decrease the system efficiency and generate heat The saturation current has to be higher than the maximum output current plus 1 2 the ripple current In over current condition the inductor current may be very high All this needs to be considered when selecting the inductor On this board Vishay IHLP4040DZ or IHLP5050 series inductors are used to meet cost requirement and get better efficiency OUTPUT CAPACITORS Voltage ESR and RMS curre
14. l 0 V pS MOSFET with 7 4 Ri smoe03 300K 50V RES 300K Q 1 10 W 5 CRCW0603300KJNEA 8 4 R2 smo603 100K 50V RES 100K 0603 CRCW0603100KFKEA 79 4 R4 SM2512 10 200V 10 2512 CRCW25121ROOFKEG 20 2 R5 R6 SM0603 100K 50V RES 100K 0603 CRCW0603100KFKEA a R7 smo603 02 50V RES 0 CRCWO06030000Z0EA 22 4 R8 smoe03 11K 50V RES 11K 0603 CRCW060311KOFKEA 23 4 R10 SM0402 5 11K 50V RES 5 11K 0402 CRCW04025K11FKED 24 R29 smoe03 10K 50V RES 10K 50 V 0603 CRCW060310KFKED 25 R12 Smo603 57 6K 50V RES 57 6K 0603 CRCW060357K6FKEA 2 1 R13 SM00402 1009 50V 100R 50 V 0402 CRCW0402100RFKED 27 R14 smo402 1009 50V 100R 50 V 0402 CRCW0402100RFKED 2 R15 sMo603 10K 50V RES 10k 50 V 0603 CRCW060310KFKED 2 1 R23 SM0402 511K 50V RES 5 11K 0402 CRCW04025K11FKED 30 R30 Smo603 69 8K 50V RES 69 8K 0603 CRCWO060369K8FKEA 31 4 R39 smo402_ 02 50V OR 50 V 0402 CRCW04020000Z0ED 32 4 R51 smos05 33R 50V RES 3 3R 0805 CRCWO08053R3FKEA 33 4 R52 Smo603 31 6K 50V RES 31 6K 50 V 0603 CRCW060331K6FKEA 34 4 U1 MLP55 32L 0 SiC402B MicroBuck Regulator 0 35 4 B1 B2 B3 B4 0 0 BANANA JACK 575 4 36 1 R9forSiC402 SMo603 26 7K RES 26 7K Q 1 10 W 1 0603 SMD _ CRCW060326K7FKEA 37 4 C24 SM0603 820 pF CAP CER 820 pF 50V 5 NP00603 C1608C0G1H821J080AA 38 4 c19 SM0603 10nF CAP GER NEE Gach 10V 10 C0603X5R1A103K030BA 30 4 PCB iC401 2 3 Demo B
15. le voltage See the following demo board schematic for R10 and R23 INPUT VOLTAGE RANGE ADJUSTMENT The input voltage range for this demo board is from 12 V to 25 V because a input power UVLO circuit is designed in to protect the demo board For the user who wants to explorer the operation of the demo board in the lower input voltage he can remove the R52 to disable the input power UVLO function of the demo board OUTPUT RIPPLE VOLTAGE The controller used in the SiC40x requires at least of 20 mV of ripple at the FB pin of the Ic This is easily attainable when using a combination of output capacitors with higher ESR like Electrolytic or Tantalum in parallel with low ESR ceramic The rule of thumb used for setting a limit for output ripple voltage is a nominal 3 of the output voltage Using this as a representative value and choosing a ripple current el that is between 20 to 40 of full load current we can now calculate for an inductor value By measuring the actual ripple voltage using the values calculated so far and adjusting one or more of the following the inductor value number of output caps and Fg used would lock in the final values chosen for the design ESR 0 03 Vout 0 4 loutmax using 40 for the ripple current L Vin Vout Vout Few Vin 0 4 loutmax When an all ceramic output capacitor is used which limits the amount of ripple voltage because of the very low ESR an additional rippl
16. mer applications e Networking and telecommunication equipment e Printers DSL and STB applications e Embedded applications e Point of load power supplies ORDERING INFORMATION DEMO BOARD PART NUMBER MAX OUTPUT CURRENT SiC403DB 6A SiC402DB 10A SiC401DB 15A Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 Gy VISHAY www vishay com THE REFERENCE BOARD This reference board allows the end user to evaluate the SiC401A B SiC402A B and SiC403A B for its features and all functionalities It can also be a reference design for a user s application SPECIFICATION Input voltage Vpc 3 V to 17 V for SiC401A B or 3 V to 25 V for SiC402A B or 3 V to 25 V for SiC403A B Output voltage Vpc 0 6 V to 5 5 V Output current A 15 A for SiC401A B or 10 A for SiC402A B or 6 A for SiC403A B Notes e This board is by default preset to 1 2 V output with 12 V input Note for inputs lower than 12 V see Input Voltage Range Adjustment page 5 e This board can be set to any output voltage between 0 6 V and 5 5 V and any input voltage between 6 V and 28 V For a specific input output voltage combination the values of inductor and ripple injection circuit may need to be modi
17. nt capability and capacitance are essential elements to consider when choosing output capacitors The ESR and capacitance affect the output voltage ripple transient response and system stability The current capability determines the capacitor power dissipation and life time To meet all of these 4 requirements a combination of ceramics and tantalums can be used Revision 22 Jan 14 2 SiC401DB SiC402DB SiC403DB Vishay Siliconix Due to the nature of this controller which requires a minimum amount of ripple of 20 mVpp to operate properly if an all ceramic output solution is required an additional ripple injection circuit R9 C19 and C24 must be used This will artificially generate ripple and apply it directly to the FB pin while the output ripple is very low More detail can be found in the datasheet and in the output voltage ripple section below CONNECTION AND SIGNAL TEST POINTS Power sockets Vin B1 Vin ano B2 Input voltage source with Viy to be positive Connect to a 12 V to 25 V source that powers SiC40xCD Vo B3 Vo anp B4 Output voltage with Vour to be positive Connect to a load that draws less than 15 A current Signal and test leads Vin P8 Vin_anp P9 Input voltage sense pins with Vin to be positive An oscilloscope or Volt meter can be connected to these terminals to measure or observe the input Vo P10 Vout anp P11 Output voltage sense pins with Vo to be positive An oscilloscope
18. oad step amplitude is correct Time base 2 ms div Bandwidth 20 MHz Connect oscilloscope channel 1 probe positive to Vo P10 and negative to Vo enp P11 and channel 2 probe positive to Vo P10 and negative to Step_ _SENSE P3 Turn on the system power Output voltage should be shown on the electronic load with current of l4 Turn on the power source for Vexrt Set the function generator output to be ON The transient response waveforms should be seen on the oscilloscope If needed re adjust the trigger waveform s rising and falling time on the function generator so that the current slew rate is satisfied the current slew rate can be seen on oscilloscope channel 2 waveform by setting the time base to 1 us or 500 ns To change load step decrease or increase the value of Vext To cease transient response test simply set the function generator output to off turn off the power source for Vext and then shut down the system power ee Switching Node Voltage 2Vidiv Output Transient __ 10us div Voltage 50mVidiv Output Transient Current 4A div Fig 1 SiC401A Transient Step Load Response in Forced Continuous Mode Revision 22 Jan 14 Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www
19. oard PCB Revision 22 Jan 14 8 Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 aay VISHAY www vishay com SiC401DB SiC402DB SiC403DB Vishay Siliconix BILL of MATERIAL for SiC403A ITEM QTY REFERENCE egorpaint VALUE VOLTAGE DESCRIPTION PART NUMBER 1 4 C1 c2 c3 c4 Smi2i0 22urF 16V CAP 22 pF 16 V 1210 GRM32ER71C226ME18L 2 4 C5 smo402 0 1pF 10V CAP 0 1 pF 10 V 0402 VJ0402Y104MXQCW1BC 3 4 C6 C7 C11 c14 SM0603 01pF 50V CAP 0 1 pF 50 V 0603 VJ0603Y104KXACW1BC 4 2 C10 C20 593D 68pF 20V 68 UF TAN 20 V 593D 20 593D686X0020D2TE3 5 4 C12 Radial 150pF 35V CAP Radial 150 pF 35 V EU FM1V151 6 1 C13 SM00402 0 01pF 50V GAP 0 01 pF 50 V 0402 VJ0402Y103KXACW1BC 7 2 AZER smiz06 100pF 10V CAP PE e C3216X5R1A107M160AC 8 4 C30 SM0402 68pF 50V GAP 68 pF 50 V 0402 VJ0402Y680KXACW1BC 9 l C26 SM0805 47pF 10V 4 7 uF 10 V 0805 LMK212B7475KG T to 4 C28 Smo402 0 1pF 10V CAP 0 1 pF 10 V 0402 VJ0402Y104MXQCW1BC mli C29 SM0603 22nF 25V CAP CER 22 nF 2 5 V VJ0603Y223KXACW1BC 2l C36 SM0402 560pF 50V CAP 5
20. orm from a function generator using the following parameters and set its output to OFF refer to the specific function generator manual for its setup Shape Pulse Frequency 50 Hz or whatever is required Duty cycle 0 1 or whatever is required keep duration small so load step resistor will not be damaged Amplitude 10 V level Rising time and falling time 1 us or whatever is required 3 Connect the function generator output positive to LDTRG and negative to GND 4 Preset the current of an electronic load to l4 and turn it on 5 Set up an oscilloscope using the following parameters Channel 1 for probing output voltage AC coupled 50 mV div or whatever is required Channel 2 for probling the current on the 1 Q resistor R4 use differential probe DC coupled 1 V div corresponds to 1 A div for the step load current more SiC401DB SiC402DB SiC403DB 10 11 12 Vishay Siliconix than 7 5 A please use 0 5 Q resistor for R4 1 V div is corresponds to 2 A div To view the output choke current a simpler method is to install a current loop using 18AWG wire after the inductor and using a current probe Lift the side of the inductor connected to the output caps and solder the loop of wire from the inductor to where it was connected on the board Keep the loop of wire just big enough for the probe to fit This will have a slight delay in the waveform compared to the output voltage but is really used to varify the l
21. tage PGOOD is pulled low It is held low until the output voltage returns above 8 of nominal PGOOD will transition low if the Veg pin exceeds 20 of nominal which is also the over voltage shutdown threshold PGOOD also pulls low if the EN PSV pin is low when Vpp is present Document Number 62923 For technical questions contact powerictechsupport vishay com THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS SET FORTH AT www vishay com doc 91000 Gy VISHAY www vishay com SET UP LOAD STEP The hardware to test transient response is included in the board which allows users to see how the transient response performs The setup steps are 1 Decide what load step is wanted then based on the output voltage calculate the external voltage Vexr that will be connected between Vetri and GND For example a load step of 5 A between 0 A l4 and 5 A lo is required and the output voltage is 1 2 V Vext Vo lo h 1 Q 1 2 5 A 0 A 1 Q 3 8 V Preset a DC source voltage to Vexr 3 8 V current capability around 2 A and connect it to the board with positive side to GND and negative side to Vetra if Vexr is a positive value then connect the DC source positive to Vetri and negative to GND Note R4 need to change to 0 5 Q for the transient load step test if the step output current is more than 7 5 A 2 Preset a wavef
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