Overview
The PCA9555PWR, produced by Texas Instruments, is a 16-bit I/O expander designed for use with the two-line bidirectional bus (I2C) and SMBus. This device operates within a voltage range of 2.3 V to 5.5 V and provides general-purpose remote I/O expansion for most microcontroller families. It features an I2C interface with serial clock (SCL) and serial data (SDA) lines, enabling communication with the system master. At power-on, the I/Os are configured as inputs, but they can be set as either inputs or outputs by writing to the I/O configuration bits.
Key Specifications
| Parameter | Value |
|---|---|
| Operating Voltage Range | 2.3 V to 5.5 V |
| Number of I/O Bits | 16 bits |
| I2C Bus Frequency | 0 Hz to 400 kHz |
| Package Type | TSSOP (24 pins) |
| Operating Temperature Range | -40°C to 85°C |
| Standby Current Consumption | 1 µA Max |
| ESD Protection | 2000 V HBM, 200 V MM, 1000 V CDM |
| Interrupt Output | Open-drain active-low |
| I/O Configuration | Input or output selection via configuration bits |
Key Features
- Low standby-current consumption of 1 µA max
- I2C to parallel port expander
- Open-drain active-low interrupt output
- 5 V tolerant I/O ports
- Compatible with most microcontrollers
- 400 kHz fast I2C bus
- Address by three hardware address pins for up to eight devices
- Polarity inversion register
- Latched outputs with high-current drive capability for directly driving LEDs
- No glitch on power-up and internal power-on reset
- ESD protection exceeds JESD 22 standards
Applications
- Routers and telecom switching equipment
- Personal computers and personal electronics
- Industrial automation equipment
- Products with GPIO-limited processors
- ACPI power switches, sensors, push buttons, LEDs, fans, etc.
Q & A
- What is the operating voltage range of the PCA9555PWR?
The PCA9555PWR operates within a voltage range of 2.3 V to 5.5 V.
- How many I/O bits does the PCA9555PWR provide?
The PCA9555PWR provides 16 bits of general-purpose parallel I/O expansion.
- What is the maximum I2C bus frequency supported by the PCA9555PWR?
The PCA9555PWR supports an I2C bus frequency of up to 400 kHz.
- What type of package is the PCA9555PWR available in?
The PCA9555PWR is available in a TSSOP (24 pins) package.
- What is the standby current consumption of the PCA9555PWR?
The standby current consumption of the PCA9555PWR is 1 µA max.
- Does the PCA9555PWR have ESD protection?
Yes, the PCA9555PWR has ESD protection that exceeds JESD 22 standards (2000 V HBM, 200 V MM, 1000 V CDM).
- How does the PCA9555PWR handle interrupt outputs?
The PCA9555PWR features an open-drain active-low interrupt output.
- Can the I/O ports of the PCA9555PWR be configured as either inputs or outputs?
Yes, the I/O ports can be configured as either inputs or outputs by writing to the I/O configuration bits.
- What is the purpose of the polarity inversion register in the PCA9555PWR?
The polarity inversion register allows the polarity of the input port register to be inverted (active high or active low operation).
- How many devices can share the same I2C bus using the PCA9555PWR?
Up to eight devices can share the same I2C bus using the PCA9555PWR, thanks to three hardware address pins (A0, A1, A2).
