IRDC3637EVAL

IRDC3637EVAL IR3637 EVALUATION BOARD USER GUIDE DESCRIPTION The IR3637 controller IC is designed to provide a low cost synchronous Buck regulator for on-board DC to DC applications in a small 8-pin SOIC. The output voltage can be precisely regulated using the internal 0.8V reference voltage for low voltage applications. The IR3637 operates at a fixed internal 400KHz switching frequency to reduce the component size. The device features under-voltage lockout for both input supplies, an external programmable soft-start function as well as output under-voltage detection that latches off the device when an output short is detected. INPUT / OUTPUT CONNECTIONS The reference board is designed for 1.8V output using +5V and +12V supplies. This will demonstrate the main features of IC. This user guide contains the schematic and bill of materials, the design guidelines are described in data sheet. SPECIFICATION DATA Vc = 12V Vcc=Vin=5V Vout=1.8V Iout =7A Output Ripple = 50mV Fs = 400KHz The connection points are shown in Figure1. Connect the power supply The following is the input / output connections: cables according to this figure, Inputs: minimizing wire lengths to reduce JP1: Input (+5V) and GND losses in the wire. Test points J1 and JU1: Vc J2 provide easy connection for Outputs: oscilloscope voltage probe to monitor JP2: Vout (+1.8V) and GND the inductor points and output voltage. Other Connections: J1: Scope connection for Vout J2: Scope connection for Inductor Point PACKAGE INFORMATION Fb 1 Vcc 2 LDrv 3 Gnd 4 Rev1.0 4/29/2005 8 SS/SD 7 Comp 6 Vc 5 HDrv 1 IRDC3637EVAL CONNECTION DIAGRAM +12V Supply +5V Supply 7A Load Figure 1 – Connection diagram of evaluation board for IR3637 Rev1.0 4/29/2005 2 IRDC3637EVAL LAYOUT The top side (component) layer for IR3637 Eval board is shown in Figure 2. The input capacitors are all located close to the MOSFETs. All the decoupling capacitors, and feedback components are located close to IC. The feedback resistors are tied to the output voltage at the point of regulation. The PCB is 4-layers board, one layer is dedicated to Power GND and the analog GND is kept separated from the PGND and it is connected at a single point. Figure 2 – Top layer of evaluation board for IR3637 Rev1.0 4/29/2005 3 IRDC3637EVAL SCHEMATIC 1 2 3 4 JP1 VIN VIN D INPUT GND D R4 C8 D1 VC VC/VCC JU1 R5 C1 VCC C5 6 C6 BAT54SCT N15 C9 + + C10 2 Q1 S1 5 HDRV D3 N25 LX C12 + + VO VCC VC C C2 SS 8 SS D1 D1 L1 J2 J1 C JP2 + VO HDRV U1 IR3637 R6 VGH G1 COMP 7 COMP LDRV 3 LDRV R7 VGL S2 G2 D2 D2 C13 C11 OUTPUT GND 1 FB FB GND 4 MOSFET N_DUAL R1 C3 B R3 C4 R9 R10 C7 N40 R8 B R2 A Title Size Orcad A Date: File: 1 2 3 IR3637 - DUAL SO8 MOSFET Number Revision Sheet of Drawn By: 4 A JE3637S-V1R0 10-Mar-2005 C:\PCB2\PCB_last6.ddb Figure 3 – Schematic of the evaluation board Rev1.0 4/29/2005 4 IRDC3637EVAL BILL OF MATERIAL Ref Desig Description Value Qty Part# Manuf Q1 U1 D3 L1 C8,9,12,13 C2,C5 C1,10,11 C3 C4 R3 R8 R9 R2,4,6,7 R1,5,10 C6,7 D1 J1,J2 JP1,JP2 JU1 Dual MOSFET Controller Diode Inductor Cap, Poscap Cap, Ceramic Cap, Ceramic Cap, Ceramic Cap, Ceramic Resistor Resistor Resistor Resistor Resistor Capacitor Diode Socket Terminal Terminal 20V, 13.4mOhm Synchronous PWM Fast Switching 1.5uH, 8A, 10 mOhm 150uF, 6.3V, 40mOhm 0.1uF, X7R, 16V 1uF, X5R, 6.3V 22pF, NPO, 100V 1800pF, X7R, 50V 16K, 1% 1.24K, 1% 1K, 1% 0 Ohm Not Used Not Used Not Used Scope probe Wire Connect 2-Pin Header 1 1 1 1 4 2 3 1 1 1 1 1 4 3 2 1 2 2 1 IRF8910 IR3637 BAT54A DO3316P-152 6TPC150M ECJ-1VB1C104K ECJ-1VB0J105K ECJ-1VC2A220J ECJ-1VB1H182K Any Any Any Any IR IR IR Coilcraft Sanyo Panasonic Panasonic Panasonic Panasonic 131-5031-00 ED1973-ND S1012-02-ND Tektronix Digi-Key Digi-Key Rev1.0 4/29/2005 5 IRDC3637EVAL TYPICAL OPERATING WAVEFORMS Test Conditions: Vcc=Vin=5V, Vc=12V, Vout=1.8V, Iout=0-7A, Ta=Room Temp, No Air Flow. Unless otherwise specified. Figure 4 - Start up waveforms Ch1: Vin=Vcc, Ch2: Vc, Ch3: Vss, Ch4: Vout Figure 5 - Start up waveforms Ch1: Vin=Vcc, Ch2: Vc, Ch3: Vss, Ch4: Vout Figure 6 - Gates waveforms Ch1: Hdrv, Ch2Ldrv,, Ch4:Inductor Current ILoad=5A Figure 7 - Gates waveforms Ch1: Hdrv, Ch2Ldrv,, Ch3:Inductor Point ILoad=5A Rev1.0 4/29/2005 6 IRDC3637EVAL TYPICAL OPERATING WAVEFORMS Test Conditions: Vcc=Vin=5V, Vc=12V, Vout=1.8V, Iout=0-7A, Ta=Room Temp, No Air Flow. Unless otherwise specified. Figure 8 - Shutdown by shorting the SS pin Ch1: Hdrv, Ch2Ldrv,, Ch3:SS ILoad=5A Figure 9 - Output Voltage Ripple Ch1: Vout, Ch4: Inductor Current ILoad=5A Figure 10 - Load Transient (0-5A) Ch1: Vout, Ch4: Step Load Current Figure 11 - Load Transient (5-0A) Ch1: Vout, Ch4: Step Load Current Rev1.0 4/29/2005 IRDC3637EVAL TYPICAL PERFORMANMCE CURVES Test Conditions: Vcc=Vin=5V, Vc=12V, Vout=1.8V, Iout=0-7A, Ta=Room Temp, No Air Flow. Unless otherwise specified. Efficiency Vc=12V, Vcc=Vbus=5V, Iout=0-8A, Fs=400KHz 100 90 80 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 9 Iout (A) Efficiency (%) Figure 12 - Efficiency using IRF8910 Dual MOSFET This product has been designed and qualified for the Industrial market. IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310)252-7105 TAC FAX: (310) 252-7903 Visit us at www.irf.com for sales contact information Data and specification subject to change without notice. 02/01 Rev1.0 4/29/2005