More DDR product information

The FAN5234 PWM controller provides high efficiency and regulation with an adjustable output from 0.9V to 5.5V that are required to power I/O, chip-sets, memory banks or peripherals 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 if PWM mode is desired for all load levels. Efficiency is even further enhanced by using MOSFET's R_DS(ON) as a current sense component.

Feed-forward ramp modulation, average current mode control, and internal feedback compensation provide fast response to load transients. The FAN5234 monitors these outputs and generates a PGOOD (power good) signal when the soft-start is completed and the output is within ±10% of its set point. A built-in over-voltage protection prevents the output voltage from going above 120% of the set point. Normal operation is automatically restored when the over-voltage conditions go away. Under-voltage protection latches the chip off when the output drops below 75% of its set value after the soft-start sequence is completed. An adjustable over-current function monitors the output current by sensing the voltage drop across the lower MOSFET.

• Wide input voltage range (2 to 24V) for Mobile systems
• Excellent dynamic response with Voltage Feed-Forward and Average Current Mode control
• Lossless current sensing on low-side MOSFET or precision over-current using sense resistor
• VCC Under-voltage Lockout
• Power-Good Signal
• Light load Hysteretic mode maximizes efficiency
• QSOP16, TSSOP16
• 300Khz or 600Khz operation

• Mobile PC regulator
• Hand-Held PC power