Description
® RT8239A/B/C High Efficiency, Main Power Supply Controller for Notebook Computers General .
The RT8239A/B/C is a dual step down, Switch Mode Power Supply (SMPS) controller which generates logic supply voltages for battery powered systems.
Features
* include on board power up sequencing, a power good output, internal softstart, and a soft discharge output that prevents negative voltage during shutdown. A constant on-time PWM control scheme operates without sense resistors and assures fast load transient response while maintaining nearly constant
Applications
* an ultrasonic mode is included, which maintains the switching frequency above 25kHz. Moreover, a diode emulation mode maximizes efficiency for light load applications. The SMPS1/SMPS2 switching frequency can be adjustable from 200kHz/233kHz to 400kHz/466kHz respectively. The RT8239A/B/C is availabl