Overview
The PCA9555BSHP, produced by NXP USA Inc., is a 24-pin CMOS device designed to provide 16 bits of General Purpose parallel Input/Output (GPIO) expansion for I2C-bus/SMBus applications. This device is part of NXP's family of I2C-bus I/O expanders and offers several enhancements, including higher drive capability, 5 V I/O tolerance, lower supply current, individual I/O configuration, and smaller packaging options. The PCA9555 is particularly useful in scenarios where additional I/O is required for devices such as ACPI power switches, sensors, push buttons, LEDs, and fans.
Key Specifications
| Parameter | Description |
|---|---|
| Package Type | HVQFN24 |
| Number of I/O Pins | 16 |
| Supply Voltage Range | 2.3 V to 5.5 V |
| I/O Voltage Tolerance | 5 V tolerant |
| Clock Frequency | 0 Hz to 400 kHz |
| Interrupt Output | Open-drain, active LOW |
| ESD Protection | Exceeds 2000 V HBM, 200 V MM, and 1000 V CDM |
| Latch-up Testing | Exceeds 100 mA (JEDEC Standard JESD78) |
| Power-on Reset | Internal power-on reset sets registers to default values |
Key Features
- Operating power supply voltage range of 2.3 V to 5.5 V
- 5 V tolerant I/Os
- Polarity Inversion register for active HIGH or active LOW operation
- Open-drain interrupt output activated on input state change
- Low standby current
- Noise filter on SCL/SDA inputs
- No glitch on power-up
- Internal power-on reset
- 16 I/O pins which default to 16 inputs
- ESD protection exceeds 2000 V HBM, 200 V MM, and 1000 V CDM
- Latch-up testing exceeds 100 mA (JEDEC Standard JESD78)
Applications
The PCA9555 is suitable for a variety of applications where additional I/O is needed, such as:
- ACPI power switches
- Sensors
- Push buttons
- LEDs
- Fans
- Other general-purpose I/O expansion needs in I2C-bus/SMBus systems
Q & A
- What is the PCA9555?
The PCA9555 is a 24-pin CMOS device that provides 16 bits of General Purpose parallel Input/Output (GPIO) expansion for I2C-bus/SMBus applications.
- What are the key enhancements of the PCA9555 over previous models?
The PCA9555 offers higher drive capability, 5 V I/O tolerance, lower supply current, individual I/O configuration, and smaller packaging options.
- What is the voltage range for the PCA9555?
The PCA9555 operates within a supply voltage range of 2.3 V to 5.5 V.
- How many I/O pins does the PCA9555 have?
The PCA9555 has 16 I/O pins.
- What is the clock frequency range for the PCA9555?
The clock frequency range is from 0 Hz to 400 kHz.
- What type of interrupt output does the PCA9555 have?
The PCA9555 has an open-drain, active LOW interrupt output.
- Does the PCA9555 have ESD protection?
Yes, the PCA9555 exceeds 2000 V HBM, 200 V MM, and 1000 V CDM for ESD protection.
- What is the purpose of the Polarity Inversion register?
The Polarity Inversion register allows for active HIGH or active LOW operation of the I/O pins.
- How does the PCA9555 handle power-on reset?
The PCA9555 has an internal power-on reset that sets the registers to their default values and initializes the device state machine.
- What types of applications is the PCA9555 suitable for?
The PCA9555 is suitable for applications such as ACPI power switches, sensors, push buttons, LEDs, fans, and other general-purpose I/O expansion needs in I2C-bus/SMBus systems.
