1 Introduction to TCA9539A-Q1 I²C GPIO expander

GPIO expanders are commonly used in automotive systems to increase input and output (I/O) availability while minimizing microcontroller pin count and routing complexity. The TCA9539-Q1 device is widely adopted in body electronics and control modules. The orderable part number TCA9539AQPWRQ1 extends this portfolio as a drop-in upgrade for automotive applications such as:

• Body control modules
• Door, mirror, and seat control modules
• Automotive lighting and LED control
• Switch and sensor input monitoring
• Zonal controllers

The TCA9539A-Q1 provides 16-bits of GPIO expansion for I²C bus designed for 1.65V to 5.5V. Key specifications and features include:

• AEC-Q100 qualification
• 400kHz I²C Fast mode
• Interrupt (INT pin) asserted when an input port changes state
• Polarity Inversion
• Hardware RESET pin
• Two I²C address schemes: TCA9539AQPWRQ1 and TCA9539BQPWRQ1 each enabling four addresses or a total of eight unique addresses on the I²C bus.