Features • Wide input voltage range (2 to 24V) for mobile system • Good dynamic response with voltage feedforward and average current mode control • Lossless current sensing with low-side MOSFET or precision over-current sense resistors • Light load hysteresis mode improves efficiency • QSOP16, using TSSOP16
• 300kHz or 600kHz operation

Applications • Voltage Regulators for Mobile PCs • Handheld PC Power Supplies

FAN5234's PWM controller provides high efficiency and regulation from 0.9V to 5.5V, adjustable output required to power I/O chipsets, memory banks or peripherals for high performance notebook computers, personal digital assistants (PDAs) and Internet devices. Synchronous rectification and hysteretic mode work at light loads with high efficiency over the load range. Hysteresis Mode Load levels can be disabled if all desired PWM modes. Even further improve the efficiency by using the RRDS(ON) of the MOSFET as the current sensing element. Feedforward ramp modulation, average current mode control and internal feedback compensation provide fast load transient response. The FAN5234 monitors these outputs and generates a PGOOD (power good) signal when soft-start is complete and the output is within ±10% of its set point. A built-in overvoltage protection prevents the output voltage from rising above the 120% set point. Overvoltage will automatically return to normal operating conditions when it disappears. The undervoltage protection latch turns off when the output falls below 75% of its set value after the chip's soft-start sequence is complete. An adjustable overcurrent function monitors the output current by detecting the lower voltage drop across the MOSFET.