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

5 Summary

The TCA9539AQPWRQ1 delivers a seamless, drop-in upgrade for TCA9539-Q1/TCA9539QPWRQ1 automotive designs, combining full pin-to-pin and software compatibility with improved system flexibility and robustness. Designers can migrate without schematic, layout, or firmware changes while immediately benefiting from a wider 1.65V to 5.5V supply range, more I²C addresses, and higher thermal margin.

With Fast-mode I²C support, integrated interrupt signaling, and hardware reset, the device enables efficient event-driven operation that reduces MCU overhead and bus traffic. Dual address variants (TCA9539AQPWRQ1 and TCA9539BQPWRQ1) allow up to eight devices on a single bus, simplifying scalable GPIO expansion in zonal and high-density architectures.

Preferred for zonal and body domain controller, infotainment, ADAS, and peripheral monitoring, the TCA9539A-Q1 reduces MCU pin count and minimizes routing complexity.

For smaller pin-count needs, the TCA9536-Q1 offers a compact (1.08mm2), 4-bit, cost-optimized alternative, while TCAL9539-Q1 extends the same 16-bit I/O architecture with advanced diagnostics and functional-safety features in the QFN package.