RT8223B - Richtek

RT8223B Main Power Supply Controller

The RT8223A/B dual step-down, switch-mode powersupply controller generates logic-supply voltages in battery-powered systems. The RT8223A/B includes two pulse-width modulation (PWM) controllers fixed at 5V/ 3.3V or adjustable from 2V to 5.5V. This device also features 2 linear regulators providing fixed 5V and 3.3V outputs. The linear regulator each provides .

Features

2 linear regulators providing fixed 5V and 3.3V outputs. The linear regulator each provides up to 70mA output current with automatic linear-regulator bootstrapping to the PWM outputs. The RT8223A/B includes on-board power-up sequencing, the power good output, internal softstart, and internal soft-discharge output that prevents negative voltages on shutdown. A constant on-time PWM control scheme operates without sense resistor and provides 100ns response to load transients while maintaining a relatively constant switching frequency. The unique ultrasonic mode maintains the switching frequency a.