Single Synchronous Buck PWM Controller with LDO Regulator

The RT8234A is a cost effective synchronous buck controller with an integrated 3A linear regulator. The PWM controller provides high efficiency, excellent transient response, and high DC output accuracy needed for stepping down high voltage batteries to generate low voltage supplies in notebook computers.
The constant on-time PWM control scheme handles wide input/output voltage ratios with ease and provides "instant-on" response to load transients while maintaining a relatively constant switching frequency. The Ultra Sonic Mode (USM) setting maintains the switching frequency above 30kHz, which eliminates noise in audio applications.
The RT8234A is intended for CPU core, chipset, DRAM, or other low voltage supplies as low as 0.75V at a reduced cost without the need for a current sense resistor.
The 3A LDO regulator maintains fast transient response, only requiring a 20μF ceramic output capacitor. In addition, the LDO supply input is provided by an external power source to significantly reduce the total power loss. The RT8234A is available in a WQFN-16L 3x3 package.