Overview
The TCA9538PWR, produced by Texas Instruments, is a low-voltage 8-bit I2C and SMBus low-power I/O expander. This device is designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface. It operates within a power-supply voltage range of 1.65 V to 5.5 V, making it versatile for various applications. The TCA9538PWR features an open-drain active-low interrupt output, an active-low reset input, and supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies on the I2C bus.
Key Specifications
| Parameter | Description |
|---|---|
| Operating Power-Supply Voltage Range | 1.65 V to 5.5 V |
| I2C Bus Frequency | 100 kHz (Standard-mode), 400 kHz (Fast-mode) |
| Number of I/O Ports | 8 bits |
| Interrupt Output | Open-drain active-low |
| Reset Input | Active-low |
| I/O Port Configuration | Input or output selection via configuration register |
| Hardware Address Pins | Two pins (A0 and A1) allowing up to four devices on the same I2C/SMBus |
| Package Type | TSSOP (16 pins), SSOP (16 pins) |
| Thermal Resistance (Junction-to-Ambient) | 122 °C/W (TSSOP), 113.2 °C/W (SSOP) |
| ESD Protection | Exceeds JESD 22 – 2000-V Human-Body Model, 1000-V Charged-Device Model |
Key Features
- Low standby current consumption
- I2C to parallel port expander
- Open-drain active-low interrupt output
- Active-low reset input
- 5-V tolerant I/O ports
- Latched outputs with high-current drive capability for directly driving LEDs
- No glitch on power-up
- Noise filter on SCL/SDA inputs
- Polarity inversion register for input ports
- Configuration, input port, output port, and polarity inversion registers
Applications
- Servers
- Routers and telecom switching equipment
- Personal computers
- Personal electronics (e.g., gaming consoles)
- Industrial automation
- Products with GPIO-limited processors
Q & A
- What is the operating voltage range of the TCA9538PWR?
The TCA9538PWR operates within a power-supply voltage range of 1.65 V to 5.5 V. - What are the supported I2C bus frequencies?
The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. - How many I/O ports does the TCA9538PWR have?
The TCA9538PWR has 8 bits of general-purpose parallel input and output (I/O) expansion. - What is the purpose of the interrupt output on the TCA9538PWR?
The open-drain active-low interrupt output is activated when any input state differs from its corresponding Input Port register state, indicating to the system master that an input state has changed. - How can the TCA9538PWR be reset?
The device can be reset by asserting a low on the RESET input pin or by cycling the power supply and causing a power-on reset (POR). - What is the significance of the hardware address pins (A0 and A1)?
The two hardware address pins allow up to four devices to share the same I2C/SMBus. - What type of ESD protection does the TCA9538PWR have?
The device exceeds JESD 22 – 2000-V Human-Body Model and 1000-V Charged-Device Model for ESD protection. - Can the TCA9538PWR directly drive LEDs?
Yes, the latched outputs have high-current drive capability for directly driving LEDs. - What is the thermal resistance of the TCA9538PWR in TSSOP and SSOP packages?
The thermal resistance (junction-to-ambient) is 122 °C/W for TSSOP and 113.2 °C/W for SSOP. - What are some common applications of the TCA9538PWR?
Common applications include servers, routers, personal computers, personal electronics, industrial automation, and products with GPIO-limited processors.
