Overview
The Texas Instruments TCA6424ARGJR is a 24-bit I/O expander designed for I2C and SMBus interfaces. It provides general-purpose remote I/O expansion for most microcontroller families, enabling the addition of 24 extra input/output pins controlled via the I2C or SMBus protocol. The device operates over a wide voltage range of 1.65 V to 5.5 V on both the P-port and SDA/SCL sides, making it compatible with various voltage levels. It features low standby current consumption, an open-drain interrupt output, a reset input, and configuration registers, making it versatile for different applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Temperature Range | -40 to 85 | °C |
| Supply Voltage Range (VCCI and VCCP) | 1.65 to 5.5 | V |
| Standby Current Consumption | 1 | µA |
| I2C Bus Frequency | 400 kHz | |
| Package Type | UQFN-32 | |
| ESD Protection | 2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model | |
| Latch-Up Performance | Exceeds 100 mA per JESD 78, Class II |
Key Features
- Allows bidirectional voltage-level translation between different voltage levels (1.8 V, 2.5 V, 3.3 V, 5 V) on the P-port and SDA/SCL sides.
- Low standby current consumption of 1 µA.
- Open-drain active-low interrupt output (INT) to signal changes in input states.
- Active-low reset input (RESET) to reset the device to its default state.
- Configuration registers for input/output selection, input, output, and polarity inversion.
- Internal power-on reset and no glitch on power up.
- Noise filter on SCL/SDA inputs and Schmitt-Trigger action for better noise immunity.
- Latched outputs with high-current drive capability for directly driving LEDs.
- 5-V tolerant I/O ports.
- Address pin (ADDR) to program and vary the fixed I2C address, allowing up to two devices to share the same I2C bus or SMBus.
Applications
- Keypad control: Can be used to scan and debounce a matrix keypad, reducing the number of pins required by the microcontroller and simplifying the software.
- LED control: Can drive multiple LEDs with different brightness levels using the PWM feature of the microcontroller and the output registers of the expander.
- GPIO control: Expands the number of general-purpose input/output pins for the microcontroller, allowing more flexibility and functionality for various applications.
Q & A
- What is the TCA6424ARGJR?
The TCA6424ARGJR is a 24-bit I/O expander for I2C and SMBus interfaces, designed to provide general-purpose remote I/O expansion for most microcontroller families.
- What is the operating voltage range of the TCA6424ARGJR?
The device operates over a voltage range of 1.65 V to 5.5 V on both the P-port and SDA/SCL sides.
- What is the standby current consumption of the TCA6424ARGJR?
The standby current consumption is 1 µA.
- What is the purpose of the open-drain interrupt output (INT) in the TCA6424ARGJR?
The INT output is activated when any input state differs from its corresponding Input Port register state, indicating to the system controller that an input state has changed.
- How does the TCA6424ARGJR handle power-on reset?
The power-on reset puts the registers in their default state and initializes the I2C/SMBus state machine. The RESET pin can also reset the device without depowering it.
- What is the significance of the configuration registers in the TCA6424ARGJR?
The configuration registers allow the system controller to set the direction, polarity, and output state of each pin, enabling flexible control over the I/Os.
- Can the TCA6424ARGJR drive LEDs directly?
Yes, the device P-port outputs have high-current sink capabilities for directly driving LEDs.
- What is the ESD protection level of the TCA6424ARGJR?
The device exceeds 2000-V Human-Body Model, 200-V Machine Model, and 1000-V Charged-Device Model for ESD protection.
- How can multiple TCA6424ARGJR devices share the same I2C bus?
Up to two devices can share the same I2C bus or SMBus by using the address pin (ADDR) to program and vary the fixed I2C address.
- What are some common applications of the TCA6424ARGJR?
Common applications include keypad control, LED control, and GPIO expansion for microcontrollers.
- What package type is the TCA6424ARGJR available in?
The device is available in a UQFN-32 package.
