DEMO BOARD QUICK START GUIDE DC424 2-PHASE, DUAL-OUTPUT SWITCHING REGULATOR CONTROLLER LTC3701 DESCRIPTION Demonstration Circuit DC424 provides 2.5V/1.6A and 1.8V/1.6A using the LTC3701 2-phase, dual-output switching regulator controller. The input range is from 2.5V to 9.8V. Operating the two controller channels 180 out of phase significantly reduces peak input ripple current; thereby reducing radiated and conducted EMI. Output voltages can be externally set to as low as 0.8V. The board is optimized for small size and low cost. Higher output current can be easily achieved by changing external components. For example, maximum output current can be increased to 2A if Murata LQH55DN4R7M01 inductors are used at the L1 and L2 locations. Switching frequency is internally set at 550kHz, allowing the use of small inductors and capacitors. For noise sensitive applications, an external clock can be applied to synchronize from 300kHZ to 750kHz. The frequency can also be externally set by apply- ing a voltage in the range from 0V to 2.4V to the PLLLPF pin. Gerber files for this circuit board are available. Call the LTC factory. Table 1. Performance Summary (Operating Temperature Range: -40C to 85C) PARAMETER CONDITION Input Voltage Range VALUE 2.5V to 9.8V VOUT1 = 2.5V; 0 to 1.6A 2.5V 3% VOUT2 = 1.8V; 0 to 1.6A 1.8V 3% Typical Output Ripple 10MHz BW; 1.6A Load; VIN = 5V 26mVP-P Typical Operating Frequency PLLLPF Pin Floating 550kHz Typical Shutdown Current VIN = 5V 15A Typical Standby Current VIN = 5V; RUN1 and RUN2 are on; No Load Current 310A Outputs QUICK START PROCEDURE Refer to Figure 1 for equipment requirements and proper setup. 1. Apply a voltage source to the input of the circuit between the Vin and GND terminals. The circuit will start up at input voltage higher than 2.5V. Do not apply more than 9.8V to the input. 2. Attach voltmeters or oscilloscope probes between VOUT1, VOUT2 and their closest GND terminals to monitor the outputs. Switch on the desired channel(s) by setting JP1 and JP2 to the run position. 3. Connect the load at each The board can supply up to each output. Higher output are possible by changing components. output. 1.6A for currents external 4. Proper hook-up is essential for ac- curate and meaningful evaluation of efficiency and regulation. Figure 1 shows the appropriate arrangement of supply, loads, ammeters and voltmeters. 1 DEMO BOARD QUICK START GUIDE DC424 2-PHASE, DUAL-OUTPUT SWITCHING REGULATOR CONTROLLER + + - - LOAD + - - + - + + - + + - BENCH SUPPLY - + - LOAD Figure 1. Proper Measurement Equipment Setup 2 5 4 3 2 1 E3 VIN 2.5V - 9.8V E8 M3 (Optional) SI9803DY 8 D R3 C9 R7 169K 3 2 1 10 C8 0.68uF 1nF R6 78.7K 1 10K JP1 RUN1 SD1 SENSE1+ R1 16 6 5 2 1 4 0.03 C6 2 ITH/RUN1 3 VFB1 4 SGND VIN 15 1 2 PGATE1 14 PGND 13 E1 VOUT1 = 2.5V@1.6A M1 C2 10uF 220pF L1 4.7uH 3 3 R10 SENSE1- C14 1uF FDC638P 10V D1 MBRM120LT3 D3 MBRS320 C1 47uF (Optional) E7 3 GND 5 2 R5 10K C4 6 VFB2 PGATE2 ITH/RUN2 PGOOD 12 C R4 1M 11 R12 C7 0 10nF 7 PLLLPF 8 SENSE2- EXTCLKMODE SENSE2+ D2 MBRM120LT3 R11 220pF 1M 10 3 JP2 RUN2 SD2 1 C D 4 U1 LTC3701EGN GND 7 6 5 4 1 2 5 6 0.03 4 R8 80.6K R9 100K C3 1 2 3 1nF M4 (Optional) SI9803DY E6 PLLLPF B C5 47uF M2 FDC638P L2 R2 9 D4 MBRS320 (Optional) E2 VOUT2 = 1.8V @1.6A 4.7uH C15 1uF 5 6 7 8 E4 PGOOD E5 EXTCLK/MODE B E9 GND L1 R3 R10 C8 C6 C9 R7 D1 R6 U1 R8 R9 D2 C4 C3 R5 A C1 M1 R1 CONTRACT NO. C2 M2 R2 APPROVALS DRAWN L2 DATE June Wu 4/17/01 TECHNOLOGY LTC3701EGN, 2-Phase Dual Step-Down Converter APPROVED ENGINEER Dongyan Zhou PCB SILKSCREEN DESIGNER 4 3 4/17/01 SIZE CAGE CODE DWG NO REV A DC424A Friday, November 16, 2001 5 A TITLE CHECKED C5 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 2 SCALE: FILENAME: SHEET 1 1 OF 1 Bill Of Material Demo Bd. # 424A Linear Technology Corporation LTC3701EGN 6/17/2005 8:05 AM Item Qty Reference 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 2 1 2 1 1 2 2 2 0 3 6 2 2 2 2 0 2 2 2 1 1 1 1 1 1 1 1 1 C1,C5 C2 C4,C6 C7 C8 C9,C3 C14,C15 D1,D2 D3,D4 (OPT) E4-E6 E1-E3,E7-E9 JP1,JP2 JP1,JP2 L1,L2 M2,M1 M3,M4 (OPT) R1,R2 R5,R10 R4,R11 R12 R6 R8 R7 R9 R3 U1 Part Description CAP., POSCAP, 47uF, 6.3V, C SIZE CAP., X7R, 10uF, 10V, 20%, 1210 CAP., X7R, 220pF, 50V, 20% 0402 CAP., X7R, 10nF, 50V, 20% 0603 CAP., 0.68uF, 10V, 20% 0603 CAP., X7R, 1nF, 50V, 20% 0402 CAP., X5R, 1uF, 6.3V, 20%, 0603 DIODE, MBRM120LT3, POWERMITE DIODE, MBRS320 SMC TURRET, TEST PIN, .061 TURRET, TEST PIN, .095 JUMPER, 0.079, 3PIN SHUNT INDUCTOR, 4.7uH, P-MOSFET, FDC638P, TSOP-6 P-MOSFET, SI9803DY, SO-8 RES., CHIP, 0.03, 1/4W, 1% 1206 RES., CHIP, 10K, 1/16W, 5% 0402 RES., CHIP, 1M, 1/16W, 5% 0603 RES., CHIP, 0, 1/16W, 0603 RES., CHIP, 78.7K, 1/16W, 1% 0402 RES., CHIP, 80.6K, 1/16W, 1%, 0402 RES., CHIP, 169K, 1/16W, 1% 0402 RES., CHIP, 100K, 1/16W, 1% 0402 RES., CHIP, 10, 1/16W, 5% 0402 I.C., LTC3701EGN, SSOP-16GN PRINTED CIRCUIT BOARDS STENCIL Page 1 - of - 1 Manufacture / Part # SANYO, 6TPA47M TAIYO TUDEN, LMK325BJ106MN AVX, 04025C221MAT AVX, 06035C103MAT TAIYO TUDEN, LMK107BJ684MA AVX, 04025C102MAT TAIYO YUDEN, JMK107BJ105MA ON SEMI., MBRM120LT3 OPTIONAL MILL-MAX 2308-2-00-44 MILL-MAX 2501-2 COMM CON, 2802S-03G1 COMM CON, CCIJ2MM-138G TOKO, A915AY-4R7M FAIRCHILD, FDC638P OPTIONAL IRC, LR1206-01-R030-F AAC, CR05-103JM AAC, CR16-105JM AAC, CJ06-000M AAC, CR05-7872FM AAC, CR05-8062FM AAC, CR05-1693FM AAC, CR05-1003FM AAC, CR05-100JM LINEAR, LTC3701EGN DEMO BOARD DC424A STENCIL DC424A