SLVSKW0 December   2025 BQ79735B-Q1

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Device and Documentation Support
    1. 4.1 Device Support
      1. 4.1.1 Third-Party Products Disclaimer
    2. 4.2 Documentation Support
      1. 4.2.1 Related Documentation
    3. 4.3 Receiving Notification of Documentation Updates
    4. 4.4 Support Resources
    5. 4.5 Trademarks
    6. 4.6 Electrostatic Discharge Caution
    7. 4.7 Glossary
  6. 5Revision History
  7. 6Mechanical, Packaging, and Orderable Information
    1. 6.1 Package Option Addendum
    2. 6.2 Tape and Reel Information
    3. 6.3 Mechanical Data

3 Description

The BQ79735B-Q1 device can be used to measure divided down high voltage nodes in a battery system. The device can measure voltage across Fuse, Contactors and check isolation voltage in battery junction box (BJB) system. There are 15 GPIOs/auxiliary inputs that can be used for HV measurements, thermistor measurements and driving relays. There are 4 SW outputs that can be used to drive MOSFET switches in the measurement path. The device can function as a SPI HUB and interface with up to 8 separate SPI devices/groups. The isolated bi-directional daisy chain ports support both capacitor and transformer based isolation. The device can also communicate with MCU over SPI.

Package Information
PART NUMBER(2)(3)PACKAGE (1)BODY SIZE (NOM)
BQ79735B-Q1HTQFP (48-pin)7mm × 7mm
(1) For all available packages, see Section 6.
(2) Any mention of BQ79735 in diagram in this data sheet refers to BQ79735B.
(3) The legacy SPI naming has been replaced with Controller and Peripheral, such that SPI pins MOSI become PICO and MISO becomes POCI.

BQ79735B-Q1 Simplified System Diagram

Simplified System Diagram