Overview
The PCA9555AHF is a low-voltage 16-bit General Purpose Input/Output (GPIO) expander produced by NXP USA Inc. This device is designed for I²C-bus/SMBus applications and provides a simple solution for expanding the number of I/Os 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
| Specification | Value |
|---|---|
| VDD Range | 1.65 V to 5.5 V |
| Number of GPIOs | 16 bits |
| Interface | I²C-bus/SMBus |
| Interrupt Output | Open-drain interrupt (INT) |
| Pull-up Resistors | Weak pull-up resistors on all input/output pins |
| Package Options | TSSOP24, HWQFN24 |
| Operating Temperature | -40°C to +85°C |
| ESD Protection | 2000 V Human Body Model, 1000 V Charged-Device Model |
| Latch-up Performance | Exceeds 100 mA per JESD78, Class II |
Key Features
- Low-voltage operation with a wide VDD range of 1.65 V to 5.5 V, allowing compatibility with next-generation microprocessors and microcontrollers.
- 16-bit GPIO expander with interrupt and weak pull-up resistors.
- Open-drain interrupt output (INT) that can be connected to the interrupt input of a microcontroller to indicate changes in input state.
- Device outputs have 25 mA sink capabilities for directly driving LEDs.
- Power-on reset sets registers to their default values and initializes the device state machine.
- Three hardware pins (A0, A1, A2) for selecting the fixed I²C-bus address, allowing up to eight devices to share the same I²C-bus/SMBus.
Applications
- ACPI power switches
- Sensors
- Push buttons
- LEDs
- Fan control
- Other applications requiring additional I/Os with minimal interconnections.
Q & A
- What is the PCA9555AHF?
The PCA9555AHF is a low-voltage 16-bit General Purpose Input/Output (GPIO) expander for I²C-bus/SMBus applications. - What is the voltage range of the PCA9555AHF?
The PCA9555AHF operates within a voltage range of 1.65 V to 5.5 V. - What types of packages are available for the PCA9555AHF?
The PCA9555AHF is available in TSSOP24 and HWQFN24 packages. - What is the purpose of the interrupt output (INT) on the PCA9555AHF?
The interrupt output (INT) is used to indicate to the system master that an input state has changed, allowing the microcontroller to be notified without continuous I²C-bus communication. - How many devices can share the same I²C-bus/SMBus using the PCA9555AHF?
Up to eight devices can share the same I²C-bus/SMBus using the three hardware address pins (A0, A1, A2). - What is the ESD protection level of the PCA9555AHF?
The PCA9555AHF has ESD protection exceeding 2000 V Human Body Model and 1000 V Charged-Device Model. - What is the latch-up performance of the PCA9555AHF?
The latch-up performance exceeds 100 mA per JESD78, Class II. - Can the PCA9555AHF directly drive LEDs?
Yes, the device outputs have 25 mA sink capabilities for directly driving LEDs. - How does the power-on reset function work on the PCA9555AHF?
The power-on reset sets the registers to their default values and initializes the device state machine. - What are some common applications of the PCA9555AHF?
Common applications include ACPI power switches, sensors, push buttons, LEDs, and fan control.
