In automotive audio systems, GPIOs are required for device enable, fault monitoring, and mode control of codecs, amplifiers, and DSPs. The TCA9539A-Q1 complements high-speed audio data interfaces such as I²S or TDM by handling low-speed control and monitoring signals as shown in Figure 4-4. Using an I2C-based GPIO expander helps isolate control functions from time-critical audio data paths while simplifying system integration.

Figure 4-4 Block Diagram of I²C GPIO Expander for Automotive Audio and Peripheral Monitoring