DATASHEET ISL8502A FN7940 Rev 0.00 2A Synchronous Buck Regulator with Integrated MOSFETs October 21, 2011 The ISL8502A is a synchronous buck controller with internal Features MOSFETs packaged in a small 4mmx4mm QFN package. The Up to 2A Continuous Output Current ISL8502A can support a continuous load of 2A and has a very wide input voltage range. With the switching MOSFETs Integrated MOSFETs for Small Regulator Footprint integrated into the IC, the complete regulator footprint can be Adjustable Switching Frequency, 500kHz to 1.2MHz very small and provide a much more efficient solution than a Tight Output Voltage Regulation, 1% Over-temperature linear regulator. Wide Input Voltage Range, 5V 10% or 5.5V to 14V The ISL8502A is capable of stand-alone operation or it can be used in a master slave combination for multiple outputs that Wide Output Voltage Range, from 0.6V are derived from the same input rail. Multiple slave channels Simple Single-Loop Voltage-Mode PWM Control Design (up to six) can be synchronized. This method minimizes the Input Voltage Feed-Forward for Constant Modulator Gain EMI and beat frequencies effect with multi-channel operation. Fast PWM Converter Transient Response The switching PWM controller drives two internal N-Channel MOSFETs in a synchronous-rectified buck converter topology. Lossless r High Side and Low Side Overcurrent DS(ON) The synchronous buck converter uses voltage-mode control Protections with fast transient response. The switching regulator provides Undervoltage Detection a maximum static regulation tolerance of 1% over line, load, Integrated Thermal Shutdown Protection and temperature ranges. The output is user-adjustable by means of external resistors down to 0.6V. Power-Good Indication Adjustable Soft-Start The output is monitored for undervoltage events. The switching regulator also has overcurrent protection. Thermal shutdown is Start-Up with Pre-Bias Output integrated. The ISL8502A features a bi-directional Enable pin Pb-free (RoHS Compliant) that allows the part to pull the enable pin low during fault detection. Applications PGOOD delay for ISL8502A has been decreased to 1ms typical Point of Load Applications (at 500kHz switching frequency) compared to 250ms (at Graphics Cards - GPU and Memory Supplies 500kHz) for ISL8502. ASIC Power Supplies Embedded Processor and I/O Supplies DSP Supplies V IN 4.5V TO 5.5V POWER GOOD POWER GOOD PGOOD PGOOD VIN V VIN IN + + ENABLE EN ENABLE EN 5.5V TO 14V PVCC SYNCH BOOT BOOT VCC M/S SS VCC ISL8502A V ISL8502A V OUT OUT PVCC PHASE PHASE SS + + SYNCH PGND PGND M/S FS FS FB FB SGND COMP SGND COMP FIGURE 1. STAND-ALONE REGULATOR: V 5.5V TO 14V FIGURE 2. STAND-ALONE REGULATOR: V 4.5V TO 5.5V IN IN FN7940 Rev 0.00 Page 1 of 20 October 21, 2011ISL8502A FN7940 Rev 0.00 Page 2 of 20 October 21, 2011 Block Diagram VCC PVCC SS PGOOD VIN (x4) VIN OC PVCC MONITOR SERIES POR 30 A REGULATOR MONITOR BIAS SGND PVCC BOOT EN FAULT MONITORING GATE DRIVE AND ADAPTIVE PHASE (x4) SHOOT THRU VOLTAGE MONITOR PROTECTION SYNCH CLOCK AND M/S OSCILLATOR GENERATOR OC 0.6V MONITOR FS REFERENCE FB COMP PGND (x4)