Introduction

Many PIC® microcontrollers have a High/Low-Voltage Detect (HLVD) module that can be used to monitor the device voltage (V_DD) and inform the user through an interrupt signal when the supply voltage drops below the specified threshold (i.e., trip point) or exceeds the trip point. This is a programmable circuit that allows the user to set the device voltage trip point and the direction of change from the trip point: positive going (exceeding the trip point), negative going (falling below the trip point) or both. This feature is useful in battery monitoring applications.

This technical brief describes the HLVD peripheral in detail. It also covers the following use cases:

• Monitoring battery discharge
• Detection of USB-power attach or detach