Overview
The PCA9557PWR, produced by Texas Instruments, is an 8-bit I2C and SMBus low-power I/O expander. This device is designed to provide general-purpose remote I/O expansion for most microcontroller families through the I2C interface. It operates within a power-supply voltage range of 2.3V to 5.5V and is known for its low standby current consumption of 1μA maximum. The PCA9557PWR features an 8-bit configuration register, input port register, output port register, and polarity inversion register, allowing for flexible configuration of the I/O pins as either inputs or outputs.
Key Specifications
| Parameter | Description |
|---|---|
| Operating Voltage | 2.3V to 5.5V |
| Standby Current | 1μA maximum |
| I/O Configuration | 8-bit input port register, 8-bit output port register, and polarity inversion register |
| Interface | I2C and SMBus |
| Addressing | Three hardware pins (A0, A1, A2) for programming the I2C address |
| Output Current | Up to 50 mA per pin (IO1 to IO7), high-current drive capability for directly driving LEDs |
| Reset | Active-low reset pin, power-on reset |
| Package Options | SOIC-16, SSOP-16, TVSOP-16, TSSOP-16 |
| Operating Temperature | -40°C to +85°C |
| Storage Temperature | -65°C to +150°C |
Key Features
- Low standby current consumption of 1μA maximum
- I2C to parallel port expander with 8-bit configuration
- Flexible I/O configuration: inputs or outputs with polarity inversion
- High-current drive capability for directly driving LEDs
- Active-low reset pin and power-on reset for initialization
- Three hardware pins for programming the I2C address, allowing up to eight devices on the same bus
- Low voltage operation: 2.3V to 5.5V
Applications
- Telecom shelters and filter units
- Servers and routers (telecom switching equipment)
- Personal computers and personal electronics
- Industrial automation
- Products with GPIO-limited microcontrollers
Q & A
- What is the operating voltage range of the PCA9557PWR?
The PCA9557PWR operates within a voltage range of 2.3V to 5.5V.
- How is the I/O configuration managed in the PCA9557PWR?
The I/O configuration is managed through an 8-bit configuration register, allowing the system controller to set the I/O pins as either inputs or outputs.
- What is the standby current consumption of the PCA9557PWR?
The standby current consumption is 1μA maximum.
- How does the reset function work on the PCA9557PWR?
The PCA9557PWR has an active-low reset pin and a power-on reset. Asserting the reset pin low or a power-on reset initializes the registers and the I2C/SMBus state machine to their default states.
- What are the package options available for the PCA9557PWR?
The PCA9557PWR is available in SOIC-16, SSOP-16, TVSOP-16, and TSSOP-16 packages.
- Can multiple PCA9557PWR devices share the same I2C bus?
Yes, up to eight devices can share the same I2C bus using the three hardware pins (A0, A1, A2) for programming the I2C address.
- What is the output current capability of the PCA9557PWR?
The output current capability is up to 50 mA per pin (IO1 to IO7), with high-current drive capability for directly driving LEDs.
- What is the operating temperature range of the PCA9557PWR?
The operating temperature range is -40°C to +85°C.
- How does the polarity inversion work on the PCA9557PWR?
The polarity of the input port register can be inverted by writing to the active HIGH polarity inversion register.
- What are some common applications of the PCA9557PWR?
Common applications include telecom shelters, servers, routers, personal computers, personal electronics, and industrial automation.
- How is the storage temperature range for the PCA9557PWR?
The storage temperature range is -65°C to +150°C.
