IRDC3622D USER GUIDE FOR DUAL OUTPUT IRDC3622D EVALUATION BOARD USING IRF6622 AND IRF6629 DIRECTFET MOSFETS Table of Contents Page Description 1 Board Features 1 Connections & Operating Instructions 2 Layout 5 Schematic 10 Bill of Materials 11 Waveforms 12 Synchronization 21 Voltage & Tracking 22 MLPQ Package 24 www.irf.com RD-0621 1 USER GUIDE FOR DUAL OUTPUT IRDC3622D EVALUATION BOARD USING IRF6622 AND IRF6629 DIRECTFET MOSFETS DESCRIPTION This user guide contains the schematic and bill of start ramp, pre-bias start-up, latched over-voltage materials for the IRDC3622D evaluation board. protection, thermal protection, accurate reference The guide describes operation and use of the voltage, on-board regulator, threshold sensitive Enable input, programmable switching frequency up evaluation board itself. The IR3622 IC is a dual 600kHz, and input under-voltage lockout for proper channel synchronous buck controller, providing a start-up. cost-effective, high performance and flexible solution. The two channels can be configured to An output over-current protection function and a either two independent outputs or current sharing hiccup current limit are implemented by sensing the single output. The current share configuration is voltage developed across the on-resistance of the ideal for high current applications. synchronous rectifier MOSFET for optimum cost and performance. Detailed application information Key features offered by the IR3622 Include for the IR3622 integrated circuit is available in the configurable dual output, output voltage tracking, IR3622 data sheet. power up/down sequencing, programmable soft- BOARD FEATURES The board is designed for two output voltages 2.5V and 1.8V up to 20A for each output. V = +12V, (13.2V Max) IN V = +2.5V 3% 20A, V = +1.8V 3% 20A O1 O2 V (ripple)= 50mV maximum for each output o F =350kHz s L1=990nH, L2=540nH C =2x100uF (SP) + 2x10uF (ceramic 0805) for 2.5V output o1 C =2x220uF (SP) + 2x10uF (ceramic 0805) for 1.8V output o2 The input voltage start threshold of the converter is set about 10V using enable pin and two external resistors (R16A1 and R16A2). The converter has the option to sequence with other supplies using SEQ and Track pins (R6A1, R16A3 and R16A4). These pins are pulled high as default. www.irf.com RD-0621 2