Overview
The PCA9538PWR, produced by Texas Instruments, is an 8-bit I2C and SMBus low-power I/O expander. This device is designed to provide general-purpose parallel input and output expansion for systems using the two-line bidirectional I2C bus or SMBus protocol. It operates within a power supply range of 2.3 V to 5.5 V and supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. The PCA9538PWR is particularly useful in applications where additional I/O ports are needed for devices such as switches, sensors, push-buttons, LEDs, and fans.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage (VCC) | 2.3 to 5.5 | V |
| Input Voltage (VI) | -0.5 to 6 | V |
| Output Voltage (VO) | -0.5 to 6 | V |
| Standby Current Consumption | 1 | μA (max) |
| I2C Clock Frequency | 100 kHz (Standard-mode), 400 kHz (Fast-mode) | |
| Operating Temperature Range | -40 to 85 | °C |
| Package Type | TSSOP16 | |
| ESD Protection | 2000-V Human-body model, 200-V Machine model, 1000-V Charged-device model |
Key Features
- Low standby current consumption of 1 μA max.
- I2C to parallel port expander.
- Open-drain active-low interrupt output.
- Hardware selectable address pins (A0 and A1) allowing up to four devices on the same I2C bus.
- Active-low reset input.
- High-current drive capability for directly driving LEDs.
- Push-pull design structure for P-port input-output.
- Interrupt generation on INT pin whenever an input port changes state.
Applications
The PCA9538PWR is suitable for a variety of applications where additional I/O ports are required. These include:
- Expanding the I/O capabilities of microcontrollers.
- Interfacing with switches, sensors, and push-buttons.
- Driving LEDs and other output devices.
- Implementing fan control and monitoring.
- Enhancing the functionality of embedded systems.
Q & A
- What is the PCA9538PWR?
The PCA9538PWR is an 8-bit I2C and SMBus low-power I/O expander produced by Texas Instruments. - What is the operating voltage range of the PCA9538PWR?
The PCA9538PWR operates within a power supply range of 2.3 V to 5.5 V. - What are the supported I2C clock frequencies?
The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. - How many devices can be connected on the same I2C bus?
Up to four PCA9538 devices can be connected on the same I2C bus using the hardware selectable address pins (A0 and A1). - What is the purpose of the INT pin?
The INT pin generates an interrupt signal whenever an input port changes state, allowing the microcontroller to be informed without continuous polling. - What is the maximum standby current consumption?
The maximum standby current consumption is 1 μA. - What type of ESD protection does the PCA9538PWR have?
The device has ESD protection exceeding JESD 22 standards for Human-body, Machine, and Charged-device models. - What is the package type of the PCA9538PWR?
The PCA9538PWR is available in a TSSOP16 package. - Can the PCA9538PWR directly drive LEDs?
Yes, the device has high-current drive capability for directly driving LEDs. - How is the device reset?
The device can be reset using the active-low reset input or by cycling the power supply to cause a power-on reset.
