5 Functional Description

The MCP16367/8/9 is a high input voltage step-down regulator capable of supplying 400 mA to a regulated output voltage ranging from 2.0V to 24V. The device features a precision-trimmed 2.2 MHz internal oscillator that provides a fixed switching frequency. Output voltage regulation is achieved through a Peak Current Mode Control architecture, which adjusts the duty cycle as needed. An internal floating driver controls the high-side integrated N-Channel MOSFET, with power supplied to the driver via an external bootstrap capacitor. This capacitor is typically biased from a fixed voltage between 3.0V and 5.5V, such as the converter’s input or output voltage. For applications where the output voltage falls outside this range (e.g., 12V), the bootstrap capacitor can be biased from the output using a simple Zener diode regulator.