SDAA267 January   2026 TCA9539-Q1 , TCA9539A-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction to TCA9539A-Q1 I2C GPIO expander
  5. 2Key Specification Comparison: TCA9539A-Q1 vs TCA9539-Q1
    1. 2.1 I²C Addressing Scheme and Compatibility
    2. 2.2 Multidevice and Zonal Architectures
  6. 3Why Use Interrupts with I²C GPIO Expanders?
  7. 4Application Examples Using TCA9539A-Q1
    1. 4.1 Zonal Controller
    2. 4.2 Infotainment and ADAS Peripheral Control
    3. 4.3 Automotive Body Control Module (BCM)
    4. 4.4 Audio and Peripheral Monitoring
  8. 5Summary
  9. 6References

Abstract

The TCA9539A-Q1 is a next-generation 16-bit I²C general purpose parallel input and output (GPIO) expander that builds on the proven functionality of TCA9539-Q1 and TCA9539QPWRQ1.

The TCA9539A-Q1 supports wider supply-voltage range and features dual address variants, as orderable part numbers TCA9539AQPWRQ1 and TCA9539BQPWRQ1, that allow up to eight devices on a single I²C bus, simplifying scalable GPIO expansion in zonal and high-density architectures. The TCA9539AQPWRQ1 is designed to be pin-to-pin and software compatible with TCA9539-Q1 and TCA9539QPWRQ1, enabling straightforward replacement in existing automotive designs while offering enhanced robustness.