Overview
The PCA9555PW, produced by Texas Instruments, is a 16-bit I2C and SMBus I/O expander designed to provide general-purpose remote I/O expansion for various microcontroller families. This device operates within a wide voltage range of 2.3 V to 5.5 V, making it versatile for different applications. It features low standby current consumption, individual I/O configuration, and an open-drain active-low interrupt output. The PCA9555PW is part of the NXP Semiconductors family of I2C-bus I/O expanders, although it is now supported by Texas Instruments.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Operating Voltage Range | VCC | 2.3 V to 5.5 V |
| Standby Current Consumption | ICC | 1 μA (maximum) |
| I/O Configuration | Input or Output | Configurable via I/O configuration bits |
| Interrupt Output | INT | Open-drain active-low |
| I2C Bus Speed | 400 kHz Fast-mode | |
| Package Type | TSSOP-24 | |
| Operating Temperature Range | Tamb | -40°C to 85°C |
| I/O Drive Capability | Up to 25 mA | |
| I/O Tolerance | 5 V tolerant |
Key Features
- Low Standby Current Consumption: Maximum of 1 μA, ideal for power-sensitive applications.
- I2C to Parallel Port Expander: Provides 16 bits of general-purpose I/O expansion.
- Individual I/O Configuration: Each I/O can be configured as either an input or an output via the I/O configuration bits.
- Open-Drain Interrupt Output: Activated when any input state differs from its corresponding input port register state.
- 5 V Tolerant I/Os: Allows for operation with 5 V logic levels.
- Schmitt-Trigger Action: Enhances noise immunity on SCL and SDA inputs.
- Internal Power-On Reset: Initializes the device state machine and sets registers to default values.
- Addressing Flexibility: Three hardware pins (A0, A1, A2) allow up to eight devices to share the same I2C-bus/SMBus.
Applications
- ACPI Power Switches: Used in power management systems.
- Sensors and Push Buttons: Expands I/O capabilities for sensor and button interfaces.
- LEDs and Fan Control: Directly drives LEDs and controls fans with its 25 mA drive capability.
- Industrial Automation Equipment: Enhances I/O capabilities in industrial automation systems.
- Personal Computers and Personal Electronics: Useful in various consumer electronics and computing devices.
- Telecom Switching Equipment: Used in telecommunications infrastructure for expanded I/O needs.
Q & A
- What is the operating voltage range of the PCA9555PW?
The PCA9555PW operates within a voltage range of 2.3 V to 5.5 V.
- What is the maximum standby current consumption of the PCA9555PW?
The maximum standby current consumption is 1 μA.
- How can the I/Os be configured on the PCA9555PW?
The I/Os can be configured as either inputs or outputs by writing to the I/O configuration bits.
- What type of interrupt output does the PCA9555PW have?
The PCA9555PW has an open-drain active-low interrupt output.
- What is the maximum drive capability of the I/Os on the PCA9555PW?
The I/Os have a maximum drive capability of 25 mA.
- Is the PCA9555PW 5 V tolerant?
Yes, the PCA9555PW is 5 V tolerant.
- How many devices can share the same I2C-bus/SMBus using the PCA9555PW?
Up to eight devices can share the same I2C-bus/SMBus using the three address pins (A0, A1, A2).
- What is the purpose of the internal power-on reset in the PCA9555PW?
The internal power-on reset initializes the device state machine and sets the registers to their default values.
- What is the operating temperature range of the PCA9555PW?
The operating temperature range is -40°C to 85°C.
- What package type is the PCA9555PW available in?
The PCA9555PW is available in a TSSOP-24 package.
