TCA6424RGJR

Introduction to TCA6424RGJR
- What it is: A 24-bit I/O expander from NXP that adds IO capability to a host MCU via I2C.
- Structure: 24 bidirectional GPIOs organized as three 8-bit banks. Each pin can be set as input or output.
- Interfaces and addressing: I2C bus (standard/fast-mode up to 400 kHz). I2C address base + A0–A2 pins, typically on 0x20–0x27.
- Features: configurable pin directions, read/write GPIO state, optional per-pin pull-ups, and an interrupt output for change events.
- Power and packaging: RoHS-compliant device with a supply range suitable for common MCU rails; available in RGJR packaging variants.
- Typical uses: expand MCU I/O for LEDs, buttons, sensors, or other peripherals in embedded designs.
In short, TCA6424RGJR is a compact, I2C-driven 24-channel GPIO expander, ideal when more I/O is needed without adding parallel buses.

TCA6424RGJR is a 24-bit I2C GPIO expander (TI TCA6424A family). Equivalent or similar-function parts from other vendors include:
- TI variants in the TCA6424A family (other package/ordering codes)
- NXP PCA9555 / PCA8575 (16-bit I2C GPIO expanders)
- Microchip MCP23017 (16-bit I2C GPIO expander)
Note: many third‑party parts are 16‑bit; two devices can be combined to match 24‑bit functionality.

TCA6424RGJR features (concise):
- 24-bit I/O expander for I2C bus (three 8-bit ports: A, B, C) with bidirectional I/O.
- I2C interface with 7-bit slave address; A0–A2 pins allow up to 8 devices on the same bus.
- Programmable I/O direction per pin and corresponding GPIO data registers.
- Optional input polarity inversion and interrupt capability.
- Interrupt output to MCU for input-change events (configurable polarity).
- Operating voltage range 1.65 V to 5.5 V; I/O pins operate at Vcc.
- I2C Fast-mode compatible (up to 400 kHz).
- Low power consumption.
- 24-pin RoHS-compliant package; available in Tape & Reel (RGJR).

Pin count: 24 pins.
Function: The TCA6424RGJR is a 24-bit I2C/SMBus I/O expander (three 8-bit ports) that adds general-purpose I/O via an I2C slave interface. It provides per-pin direction control (input/output), output registers, input-polarity inversion, interrupt output for pin-change events, and hardware reset. Typical signals include SDA, SCL, INT, RESET, three address pins, VCC and GND plus the 24 GPIO pins arranged as Port0/Port1/Port2.

The TCA6424RGJR is manufactured by Texas Instruments (TI). TI is an American, publicly traded semiconductor company (NASDAQ: TXN) that designs and manufactures analog and embedded processing integrated circuits and related semiconductor products — including mixed-signal ICs, power-management devices, microcontrollers, interface and sensor chips — for industrial, automotive, communications and consumer electronics markets.

- 24-bit I/O expander over I2C for microcontrollers/SoCs with limited GPIOs (three 8-bit ports).
- Scales digital I/O in embedded systems for simple control and sensing.
- Common uses: driving LEDs/LED matrices, reading pushbuttons and switches, keypad scanning, interfacing with simple sensors, and driving relays/optocouplers.
- Suitable for development boards (Raspberry Pi, Arduino), robotics, home/industrial automation, and automotive electronics where many I/O signals are needed on a single I2C bus.

The TCA6424RGJR is supplied in a 24-pin TSSOP (thin shrink small-outline) package, RoHS-compliant and tape-and-reel packaged.