FAN5233

The FAN5233 is a high efficiency and high precision multiple-output voltage regulator for notebook PC and other similar battery-powered applications. It integrates three pulse-width modulated (PWM) switching regulator controllers and one linear regulator to convert 5.4V-to-24V notebook battery power into the voltage used by the circuitry that surrounds the microprocessor in these systems.
The two primary PWM controllers in the FAN5233 use synchronous-mode rectification to provide 3.3V and 5V at over 5A each. They switch out-of-phase to minimize input ripple-current. Utilization of both input and output voltage feedback in a current-mode control allows for fast and stable loop response over a wide range of input and output variations. PWM control in normal operation and hysteretic control under light load provides efficiency of greater than
95% over a wide range of input and output variations. The third PWM controller generates 12V at 120mA. A propri-etary technology is used for sensing of output current using the RDS(ON) of the external MOSFETs, eliminating exter-nal current sense resistors which saves board space and
reduces BOM cost.
One integrated linear regulator provides stand-by ALWAYS-ON power at 5V for light (50mA) loads. Additional FAN5233 features include over-voltage, under-
voltage, and over-current monitors and thermal shutdown protection. A single Power-Good signal is issued when soft start is completed and all outputs are within ±10% of their settings.