TCAL9539RTWRQ1 is TI's automotive-grade 16-bit I2C/SMBus IO expander that expands 16 independently configurable GPIO ports for microcontrollers or processors via a two-wire I2C/SMBus interface. Each port can be independently configured as input or output mode with optional pull-up resistors (up to 100kohm). Operating voltage range of 1.65V to 5.5V enables seamless connection with 1.8V/3.3V/5V systems.

The device has a built-in open-drain interrupt output pin (INT). When any port is configured as input and a level change is detected, the INT pin is pulled low to notify the host without requiring polling, reducing system power consumption. In standby mode, quiescent current is below 1uA.

AEC-Q100 automotive certified with an operating temperature range of -40 degrees C to +125 degrees C, suitable for automotive BCM, ADAS cameras, instrument clusters, and body electronics applications.

Note: For detailed electrical parameters, refer to the official TI datasheet. Specifications are subject to change without notice. Engineers should verify all parameters before final design.

TCAL9539RTWRQ1 uses a standard TSSOP-24 (RTW) package measuring 4.4mm x 7.6mm with 0.65mm pin pitch. TSSOP (Thin Shrink Small Outline Package) is a 24-pin gull-wing package suitable for standard SMT assembly. The low-profile package (approximately 1.1mm height) is ideal for board-thickness-sensitive automotive modules. The package is RoHS compliant and supports lead-free soldering.

TCAL9539RTWRQ1 in TSSOP-24 package has 24 functional pins:

• Pins 1-8 - P00~P07 (Port 0): 8 bidirectional IO pins for Port 0. Each pin independently configurable as input or output. Input mode enables 100kohm internal pull-up; output mode supports push-pull or open-drain structure.
• Pin 9 - GND: Device ground pin.
• Pins 10-17 - P10~P17 (Port 1): 8 bidirectional IO pins for Port 1, same function as Port 0.
• Pin 18 - INT (Interrupt Output): Open-drain interrupt output pin. Pulled low when any input-configured port detects a level change. Requires external pull-up resistor (connect to VCC).
• Pin 19 - SCL (Clock): I2C/SMBus serial clock input pin. Requires external pull-up resistor (recommended 10kohm).
• Pin 20 - SDA (Data): I2C/SMBus serial data bidirectional pin. Open-drain, requires external pull-up resistor (recommended 10kohm).
• Pin 21 - A0 (Address): I2C slave address pin. Can connect to VCC/GND or function as additional input IO, used to set device slave address.
• Pin 22 - A1 (Address): Same as A0, for further I2C address configuration.
• Pin 23 - VCC: Device supply positive terminal (1.65V to 5.5V). A 0.1uF decoupling capacitor should be placed close between VCC and GND.
• Pin 24 - A2/NC (Address/No Connect): Can serve as third address pin for address setting, or left floating.

The following alternative parts are listed for reference. Before selecting an alternative, verify operating voltage range, IO port count, package compatibility, and I2C address configuration method.

Selection tips: Key points: operating voltage range must cover target system levels; IO port count must be sufficient; package must be compatible with PCB layout; I2C address must not conflict with other I2C devices on the bus.

Texas Instruments (NASDAQ: TXN), headquartered in Dallas, Texas, USA, is one of the world's largest analog semiconductor companies. TI's products span amplifiers, data converters, interface chips, embedded processors, and power management devices. The I2C/SMBus interface product line includes IO expanders, level shifters, real-time clocks (RTC), and EEPROMs, widely used in automotive electronics and industrial automation.

TCAL9539RTWRQ1 belongs to TI's TCAL95xx automotive IO expander family, designed for space-constrained automotive modules. TI provides complete reference designs and I2C driver examples for Chinese automotive customers, supporting rapid integration into AutoSAR and Linux embedded systems.