Power Management

Cross Reference

Application Notes


Tools & Software

Block Diagrams

PowerLab™ Reference Design Library

WEBENCH® Design Center

HDQ Communication Basics (Rev. A)


This report compares the communication timing specifications for the different battery gas gauge and battery monitor products. It discusses some of the interface requirements necessary for robust HDQ communication, such as the need for a break prior to each communication, how to reliably read 16-bit dynamic values over the 8-bit bus, and the need for some noise filtering on the HDQ line. It also discusses the firmware strategy required for implementing the HDQ interface using a discrete I/O port and describes the popular option of using a UART to handle the HDQ bit timing requirement