Overview
The PCA9538A, produced by NXP USA Inc., is a low-voltage 8-bit General Purpose Input/Output (GPIO) expander designed for I²C-bus/SMBus applications. This device provides a simple solution for expanding the number of I/O ports in a system while minimizing interconnections. It is particularly useful in applications such as ACPI power switches, sensors, push buttons, LEDs, and fan control.
Key Specifications
| Parameter | Value |
|---|---|
| Operating Power Supply Voltage Range | 1.65 V to 5.5 V |
| Standby Current Consumption | 1.5 μA (typical at 5 V VDD), 1.0 μA (typical at 3.3 V VDD) |
| I²C-bus Speed | 400 kHz Fast-mode |
| Reset Input | Active LOW reset input |
| Interrupt Output | Open-drain active LOW interrupt output |
| I/O Drive Capability | 25 mA maximum for directly driving LEDs |
| ESD Protection | 2000 V Human Body Model, 1000 V Charged-Device Model |
| Package Options | TSSOP16, HVQFN16 |
Key Features
- I²C-bus to parallel port expander
- Schmitt-trigger action on SCL and SDA inputs for better noise immunity
- 5 V tolerant I/Os
- Internal power-on reset
- Power-up with all channels configured as inputs, no glitch on power-up
- Latched outputs with 25 mA drive capability
- Latch-up performance exceeds 100 mA per JESD78, Class II
Applications
- ACPI power switches
- Sensors
- Push buttons
- LEDs
- Fan control
- General-purpose I/O expansion in microprocessor and microcontroller systems
Q & A
- What is the PCA9538A?
The PCA9538A is a low-voltage 8-bit General Purpose Input/Output (GPIO) expander for I²C-bus/SMBus applications.
- What is the operating power supply voltage range of the PCA9538A?
The operating power supply voltage range is from 1.65 V to 5.5 V.
- What is the standby current consumption of the PCA9538A?
The standby current consumption is 1.5 μA (typical at 5 V VDD) and 1.0 μA (typical at 3.3 V VDD).
- What is the I²C-bus speed of the PCA9538A?
The I²C-bus speed is 400 kHz Fast-mode.
- What type of reset input does the PCA9538A have?
The PCA9538A has an active LOW reset input.
- What type of interrupt output does the PCA9538A have?
The PCA9538A has an open-drain active LOW interrupt output.
- What is the maximum drive capability of the I/Os?
The I/Os can drive up to 25 mA, suitable for directly driving LEDs.
- What kind of ESD protection does the PCA9538A offer?
The PCA9538A offers ESD protection exceeding 2000 V Human Body Model and 1000 V Charged-Device Model.
- In what packages is the PCA9538A available?
The PCA9538A is available in TSSOP16 and HVQFN16 packages.
- What are some common applications of the PCA9538A?
Common applications include ACPI power switches, sensors, push buttons, LEDs, and fan control.
- Does the PCA9538A have internal power-on reset?
Yes, the PCA9538A has an internal power-on reset.
