Programmable Output Voltage Single Synchronous Buck Controller

The RT8208A/B is a constant-on-time PWM controller which provides four resistor programmable DC output voltages by controlling the G0 and G1 digital input. The output voltage is programmable from 0.75V to 3.3V. The RT8208A/B offers the lowest total solution cost in systems where need output voltage slewing. The RT8208A/B provides an automatic masking power good output during output voltage transition.
The constant-on-time PWM control scheme handles wide input/output ratios with ease and provides 100ns "instant-on" response to load transient while maintaining a relatively constant frequency. It provides the high efficiency, excellent transient response, and DC output accuracy needed for stepping down high voltage batteries to generate low voltage CPU core, graphics, I/O and chipset RAM supplies in notebook computers.
The RT8208A/B achieves high efficiency at a reduced cost by eliminating the current sense resistor in traditional current mode PWMs. Efficiency is further enhanced by its ability to drive very large synchronous rectifier MOSFETs. The buck conversion allows this device to directly step down from high voltage batteries for the highest possible efficiency. Additional features include soft-start, under voltage protection, programmable over current protection and non-overlapping gate drive.The RT8208A/B is available in a WQFN-16L 3x3 package.