Back to Texas Instruments

Texas Instruments TCAL9539/TCAL9539-Q1 I2C-Bus/SMBus I/O Expander

Texas Instrument TCAL9539/TCAL9539-Q1 I2C-Bus/SMBus I/O Expander provides a general-purpose parallel input/output (I/O) expansion for the two-line bidirectional I2C bus (or SMBus) protocol. This device is designed for 1.08V to 3.6V VCC operation. The device supports 100kHz (Standard-mode), 400kHz (Fast-mode), and 1MHz (fast-mode-plus) I2C clock frequencies. I/O expanders such as the TCAL9539/TCAL9539-Q1 provide a simple solution when additional I/Os are needed for sensors, switches, push buttons, LEDs, fans, etc.

The TCAL9539/TCAL9539-Q1 has Agile I/O ports, which include additional features designed to enhance the I/O performance in terms of power consumption, speed, and EMI. Other features are programmable pull-up and pull-down resistors, programmable output drive strength, latchable inputs, interrupt status register, maskable interrupt, and programmable open-drain or push-pull outputs. The Texas Instruments TCAL9539-Q1 devices are AEC-Q100 qualified for automotive applications.

Features

  • Operating power-supply voltage range of 1.08V to 3.6V
  • Low standby current consumption of 1µA typical at 1.8mV
  • 1MHz fast mode plus I2C bus
  • Hardware address pin allows two devices on the same I2C, SMBus bus
  • Active-low reset input (RESET)
  • Open-drain active-low interrupt output (INT)
  • Input or output configuration register
  • Polarity inversion register
  • Configurable I/O drive strength register
  • Pull-up and pull-down resistor configuration register
  • Internal power-on reset
  • Noise filter on SCL or SDA inputs
  • Latched outputs with high-current drive maximum capability for directly driving LEDs
  • Latch-up performance exceeds 100 mA per JESD 78, class II
  • ESD protection exceeds JESD 22
    • 2000V Human-body model (A114-A)
    • 1000V Charged-device model (C101)

Applications

  • Servers
  • Routers (telecom switching equipment)
  • Personal computers
  • Personal electronics
  • Industrial automation
  • Gaming consoles
  • Products with GPIO-limited processors

Datasheet

Simplified Schematic

Schematic - Texas Instruments TCAL9539/TCAL9539-Q1 I2C-Bus/SMBus I/O Expander
Published: 2024-01-17 | Updated: 2025-08-07