IRDC3448-P1V0 SupIRBuck TM USER GUIDE FOR IR3448 EVALUATION BOARD DESCRIPTION A thermally compensated output over-current protection function is implemented by sensing the voltage developed across the on-resistance of the synchronous rectifier MOSFET for optimum cost and performance. The IR3448 is a synchronous buck converter, providing a compact, high performance and flexible solution in a small 5mmx6mm QFN package. Key features offered by the IR3448 include internal Digital Soft Start, precision 0.6V reference voltage, Power Good, thermal protection, programmable switching frequency, Enable input, input under-voltage lockout for proper start-up, enhanced line/ load regulation with feed forward, external frequency synchronization with smooth clocking, internal LDO, true differential remote sensing and pre-bias start-up. This user guide contains the schematic and bill of materials for the IR3448 evaluation board. The guide describes operation and use of the evaluation board itself. Detailed application information for IR3448 is available in the IR3448 data sheet. BOARD FEATURES • Vin = +12V (+ 13.2V Max), No Vcc required. • Vout = +1.0V @ 10A • Fs = 600kHz • L = 0.51uH • Cin = 3x22uF (ceramic 1206) + 1x330uF (electrolytic, optional)) • Cout = 5x100uF (ceramic 0805) * * If cost is critical, the Cout can be replaced by 5x47uF/0805/6.3V/X5R with compensation changes in Table II. This updated 5x47uF design can still meet the Intel P1V0 rail spec. in 546835_PDG_Purley_EP_rev0_7. 3/26/2014 Confidential 1 This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 CONNECTIONS and OPERATING INSTRUCTIONS A well regulated +12V input supply should be connected to VIN+ and VIN-. A maximum of 10A load should be connected to VOUT+ and VOUT-. The inputs and output connections of the board are listed in Table I. IR3448 needs only one input supply and internal LDO generates Vcc from Vin. If operation with external Vcc is required, then R33 should be removed and external Vcc can be applied between Vcc+ and Vcc- pins. Vin pin and Vcc pins should be shorted together for external Vcc operation by installing R35. The board is configured for remote sensing. If local sense is desired, R8 should be uninstalled and R16 should be installed instead. External Enable signal can be applied to the board via exposed Enable pad and R18 should be removed for this purpose. Table I. Connections Connection Signal Name VIN+ Vin (+12V) VIN- Ground of Vin Vout+ Vout(+1.0V) Vout- Ground for Vout Vcc+ Vcc Pin Vcc- Ground for Vcc input Enable Enable PGood Power Good Signal AGnd Analog ground LAYOUT The PCB is a 6-layer board. All of layers are 2 Oz. copper. The IR3448 and most of the passive components are mounted on the top side of the board. Power supply decoupling capacitors and feedback components are located close to IR3448. The feedback resistors are connected to the output of the remote sense amplifier of the IR3448 and are located close to the IR3448. To improve efficiency, the circuit board is designed to minimize the length of the on-board power ground current path. Separate power ground and analog ground are used and may be connected together using a 0 ohm resistor at one of three possible locations. It is preferred to use one of R43 or R44. 3/26/2014 Confidential 2 This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 CONNECTIONS and OPERATING INSTRUCTIONS LAYOUT The PCB is a 6-layer board. All of layers are 2 Oz. copper. The IR3448 and most of the passive components are mounted on the top side of the board. Power supply decoupling capacitors and feedback components are located close to IR3448. The feedback resistors are connected to the output of the remote sense amplifier of the IR3448 and are located close to the IR3448. To improve efficiency, the circuit board is designed to minimize the length of the on-board power ground current path. Separate power ground and analog ground are used and may be connected together using a 0 ohm resistor at one of three possible locations. It is preferred to use one of R43 or R44. Vin Gnd Gnd Vo Top View 3/26/2014 Confidential 3 This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL 1 VPB 1 Vout_Adj N/S C9 N/S Vp M3 Vp R41 N/S C52 N/S 2 Vout R26 D2 PG_PU PG_Pullup N/S 11 Rt/Sy nc N/S D3 Sy nc Optional Pre-Bias test circuit 2 1 1 Sy nc 100pF C10 1 1 R40 N/S 1 Vref Optional "1-bit VID" circuit N/S N/S R27 PGD PGood Vp 1 Fb Vcc- 4 OCSelect 2 1 3 Agnd 4pin jumper C68 N/S R17 10K NC0 NC1 NC2 NC3 NC4 Rt/Sy nc OCSelect PGD Vcc Comp FB RSo Vp Vref IR3448 1 N/S 6.49K 9.76K N/S R21 C8 Vsns 2200pF R2 127 C50 N/S 0.1uF C37 C39 1uF 2 C56 N/S C54 N/S R28 C55 N/S C25 0.1uF R3 Fb 13 6 20 21 22 23 24 25 32 2 26 C57 N/S R4 RS+ Vsns SW SW SW SW SW SW SW Boot PGnd Vin R33 0 49.9K R35 VCC R18 SWs R6 20 BODE Vout Vsns C7 N/S N/S R16 Vo_R_N Vo_R_P 6.49K R15 C24 N/S R20 N/S 0.51uH L1 C31 N/S N/S C38 JUMPER 2 0 R11 N/S R12 0 R10 9.76K R32 C32 N/S 3 x 22uF / 1206 / 25V Ceramic N/S C44 N/S N/S 0 R44 N/S N/S N/S C43 C40 5 x 100uF / 0805 / 4V Ceramic C27 1 x 330 uF / 25V / Electrolytic C4 22uF C28 R43 N/S C42 N/S C29 C5 N/S N/S C41 N/S C20 C3 22uF C18 + C17 330uF C1 C16 0 ohm R30 0 ohm C15 N/S C21 N/S C22 + C35 N/S + C36 N/S + 100uF 100uF 100uF 100uF 100uF C19 C2 22uF PVin R31 C34 N/S + C14 0.1uF Vin- Vin+ Vout 6 5 4 3 2 1 6 5 4 3 2 1 C51 N/S 6 5 4 3 2 1 6 5 4 3 2 1 Ground and Signal ( “analog” ) Ground Single point of connection between Power N/S C45 N/S N/S C33 C30 C6 N/S Fig. 1: Schematic of the IR3448 evaluation board R9 39.2K 19 28 30 31 33 Rt/Sy nc 4 5 16 PGD 8 7 9 U3 PG_PU R29 10K Vcc+ 4.7nF C26 C11 120pF 18 C66 10uF VCC 5.62K R1 0 R8 R19 7.5K Enable VDDQ 1 15 NC5 1 3 CByp 14 17 Vin Vref LGnd 11 1 PVin PGnd PGnd PGnd 10 27 29 1 1 RS12 3/26/2014 1 Enable Vout- Vout+ IRDC3448-P1V0 Confidential 4 * If cost is critical, the Cout can be replaced by 5x47uF/0805/6.3V/X5R with compensation changes in Table II. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 Schematic for Transient Load set up Vout VCC 3 1 R22 ExtLoadCtrl R23 2 1 N/S N/S S3 SW N/S R24 N/S R36 N/S U2 1 2 3 4 R39 N/S C46 N/S C49 N/S VS VS IN OUT2 N/A OUT1 GND GND 8 7 6 5 MIC4452/SO8 N/S R37 N/S R53 N/S R54 N/S D7 N/S D6 N/S Vo_R_P R25 M1 IRF6721 N/S Vout N/S C47 N/S C48 N/S 1 R38 N/S C58 N/S C59 N/S C60 N/S C61 N/S C62 N/S C65 N/S C64 N/S C63 N/S I-Monitor Vo_R_N Optional transient load circuit Table II. Compensation Changes Between 5x100uF Design and 5x47uF Design 3/26/2014 Confidential 5 This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 Bill of Materials (5x100uF Design) Item Qty 1 3 2 1 C1 330uF 3 4 5 6 1 3 1 1 100pF 0.1uF 2200pF 120pF 7 5 100uF 0805, 4V, X5R, 20% Murata GRM21BR60G107ME15L 8 9 10 11 12 13 14 15 1 1 1 2 2 1 1 1 4.7nF 4.3nF 0.51uH 5.62K 6.49K 9.76K 127 20 39.2K 0603, 50V, X7R, 10% 0.51uH, DCR=0.29mohm 0603,1/10 W,1% 0603,1/10 W,1% 0603,1/10 W,1% 0603,1/10 W,1% 0603,1/10 W,1% 0603,1/10 W,1% Murata Coiltronics Panasonic Panasonic Panasonic Panasonic Vishay/Dale Panasonic GRM188R71H472KA01D GRM188R71H432KA01D FP1107R1-R51-R ERJ-3EKF5621V ERJ-3EKF6491V ERJ-3EKF9761V ERJ-3EKF1270V CRCW060320R0FKEA ERJ-3EKF3922V 16 5 0 0603,1/10 W,5% Vishay/Dale CRCW06030000Z0EA 17 18 19 20 21 22 23 1 1 1 2 1 1 2 C10 C14 C25 C37 C8 C11 C15 C16 C17 C18 C19 C26 L1 R1 R2, R15 R3, R32 R4 R6 R9 R8 R10 R11 R33 R44 C39 C66 R28 R30 R31 R18 R19 R17 R29 Description 1206, 25V, X5R, 10% SMD Elecrolytic, Fsize, 25V, 20% 0603, 50V, C0G, 5% 0603, 25V, X7R, 10% 0603, 50V, X7R, 10% 50V, 0603, NP0, 5% 24 1 Jumper 25 2 Vin+ Vout+ RED 26 2 Vin- Vout- BLACK 27 1 U1 IR3448 3/26/2014 Part Reference C2 C3 C4 Value 22uF 1uF 10uF 2 0 49.9K 7.5K 10K Manufacturer Murata Part Number GRM31CR61E226KE15L Panasonic EEE-FK1E331P Murata Murata Murata Murata GRM1885C1H101JA01D GRM188R71E104KA01D GRM188R71H222KA01D GRM1885C1H121JA01D 0603, X5R, 25V TDK 0603, X5R, 10V TDK Yageo 0603,1/10 W,1% 1206,1/4 W,5% Yageo 0603,1/10 W,1% Panasonic 0603,1/10 W,1% Panasonic 0603,1/10 W,1% Panasonic PLUG 40 POS DBL ROW Omron STR Electronics Inc Keystone SCREW TERMINAL Electronics Keystone SCREW TERMINAL Electronics International IR3448 5mm X6mm Rectifier Confidential C1608X5R1E105M C1608X5R1A106M RC0603FR-072RL RC1206JR-070RL ERJ-3EKF4992V ERJ-3EKF7501V ERJ-3EKF1002V XG8W-4041-ND 8199-2 8199-3 IR3448MPBF 6 This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 TYPICAL OPERATING WAVEFORMS Vin=12.0V, Vo=1.0V, Io=0A-10A, 600kHz, Room Temperature, No air flow Fig. 2: Start up at 10A Load Ch1:Vin, Ch2:Vo, Ch3:PGood, Ch4:Enable Fig. 3: Start up at 10A Load, Ch1:Vin, Ch2:Vo, Ch3:PGood,Ch4:Vcc Fig. 4: Start up with 1.05V Pre Bias , 0A Load, Ch2:Vo, Fig. 7: Short (Hiccup) Recovery Ch2:Vo, Ch3:PGood, Ch4=Io Fig. 6: Inductor node at 10A load Ch1:LX 3/26/2014 Fig. 5: Output Voltage Ripple, 10A load Ch2: Vo Confidential 7 Note that the results in the page are conducted with 5x100uF design. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 TYPICAL OPERATING WAVEFORMS Vin=12.0V, Vo=1.0V, Io=1.6A-6.4A, 600kHz, Room Temperature, No air flow Fig. 8: Transient Response, 1A to 5A step (3A/us) Ch2:Vout 3/26/2014 Confidential 8 Note that the results in the page are conducted with 5x100uF design. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 TYPICAL OPERATING WAVEFORMS Vin=12.0V, Vo=1.0V, Io=11.2A-10A, 600kHz, Room Temperature, No air flow Fig. 9: Transient Response, 6A to 10A step (3A/us) Ch2:Vout 3/26/2014 Confidential 9 Note that the results in the page are conducted with 5x100uF design. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 TYPICAL OPERATING WAVEFORMS Vin=12.0V, Vo=1.0V, Io=10A, 600kHz, Room Temperature, No air flow Fig. 10: Bode Plot at 10A load shows: Fc = 102.9kHz, Phase Margin = 48.82º, Gain Margin = -20.24dB 3/26/2014 Confidential 10 Note that the results in the page are conducted with 5x100uF design. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 TYPICAL OPERATING WAVEFORMS Vin=12.0V, Vo=1.0V, Io=0-10A, 600kHz, Room Temperature, No air flow p Fig.11: g Efficiency y versus load current Fig.12: Power loss versus load current 3/26/2014 Confidential 11 Note that the results in the page are conducted with 5x100uF design. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL IRDC3448-P1V0 THERMAL IMAGES Vin=12.0V, Vo=1.0V, Io=10A, 600kHz, Room Temperature, No air flow Fig. 13: Thermal Image of the board at 16A load Test point 1 is IR3448: 43.580C Test point 2 is inductor: 39.150C 3/26/2014 Confidential 12 Note that the results in the page are conducted with 5x100uF design. This evaluation board is a preliminary version meant for the engineering evaluation of the IR3448. Based on the results of the continuing evaluation, this board can evolve and change without notice AL