FAN5236

www.fairchildsemi.com FAN5236 Dual Mobile-Friendly DDR / Dual-output PWM Controller Features Highly flexible dual synchronous switching PWM controller includes modes for: – DDR mode with in-phase operation for reduced channel interference – 90˚ phase shifted two-stage DDR Mode for reduced input ripple – Dual Independent regulators 180° phase shifted Complete DDR Memory power solution – VTT Tracks VDDQ/2 – VDDQ/2 Buffered Reference Output Lossless current sensing on low-side MOSFET or precision over-current using sense resistor VCC Under-voltage Lockout Converters can operate from +5V or 3.3V or Battery power input (5 to 24V) Excellent dynamic response with Voltage Feed-Forward and Average Current Mode control Power-Good Signal Also supports DDR-II and HSTL Light load Hysteretic mode maximizes efficiency QSOP28, TSSOP28 General Description The FAN5236 PWM controller provides high efficiency and regulation for two output voltages adjustable in the range from 0.9V to 5.5V that are required to power I/O, chip-sets, and memory banks in high-performance notebook computers, PDAs and Internet appliances. Synchronous rectification and hysteretic operation at light loads contribute to a high efficiency over a wide range of loads. The hysteretic mode of operation can be disabled separately on each PWM converter if PWM mode is desired for all load levels. Efficiency is even further enhanced by using MOSFET’s RDS(ON) as a current sense component. Feed-forward ramp modulat...