1 Features

1• High-Accuracy Coulomb Counter with Input Offset

Error < 1 μV (Typical)

• High-Side FET Drive Allows Serial Bus

Communication During Fault Conditions

• Analog Front End with Two Independent ADCs

– Support for Simultaneous Current and Voltage

Sampling

• Bus Communications Interface Options

– I2C

– HDQ

• SHA-1 Hash Message Authentication Code

(HMAC) Responder for Increased Battery Pack

Security

– Split Key (2 × 64) Stored in Secure Memory

• Programmable Protection Levels for:

– Overcurrent in Discharge

– Short-Circuit Current in Charge

– Short-Circuit Current in Discharge

– Overvoltage

– Undervoltage

– Overtemperature

• Supports a 1-mΩ to 3-mΩ Current Sense Resistor

• Compact 12-Terminal SON Package (DRZ)

2 Applications

• Portable and Wearable Health Devices

• Portable Radios

• Industrial Data Collection

3 Description

The bq78z100 device provides a fully integrated

pack-based solution with a flash programmable

custom reduced instruction-set CPU (RISC), safety

protection, and authentication for 1-series to 2-series

cell Li-Ion and Li-Polymer battery packs.

The bq78z100 gas gauge communicates via an I2C-

compatible interface or single-wire HDQ interface and

combines an ultra-low-power, high-speed TI bqBMP

processor, high-accuracy analog measurement

capabilities, integrated flash memory, an array of peripheral and communication ports, an N-channel

FET drive, and a SHA-1 Authentication transform

responder into a complete, high-performance battery

management solution.

The bq78z100 device provides an array of battery

and system safety functions, including overcurrent in

discharge, short circuit in charge, and short circuit in

discharge protection for the battery, as well as FET

protection for the N-channel FETs, internal AFE

watchdog, and cell balancing. Through firmware, the

devices can provide a larger array of features

including protection against overvoltage, undervoltage, overtemperature, and more.