The MC33565 Low Drop Out Voltage Regulator is designed for computer peripheral card applications, allowing glitch–free transitions from “sleep” to “active” system modes. It has internal logic circuitry to detect whether there is a 5.0 V supply (“active” system mode) or an auxiliary 3.3 V supply (“sleep” system mode). A guaranteed 3.3 V regulated output voltage at 200 mA is always available even if the main 5.0 V supply drops out. The regulated 3.3 V output voltage is provided by either an internal low dropout voltage regulator or an external P–channel MOSFET switch, depending on the system being in the “active” or “sleep” mode.

Features
•Glitch–Free Transition from “Sleep” to “Active” Mode
•Compatible with Instantly Available PC Systems
•Output Current up to 200 mA
•Output Regulated to 2% over Temperature
•Excellent Line and Load Regulation (0.4%)
•Prevents Reverse Current Flow during Sleep Mode
•Short Circuit Protection