Overview
The PCA9555PWRG4, produced by Texas Instruments, is a 16-bit I2C and SMBus I/O expander designed for remote I/O expansion in various applications. It operates within a voltage range of 2.3-V to 5.5-V and is compatible with most microcontroller families via the I2C interface. The device features two 8-bit configuration registers, input port, output port, and polarity inversion registers, allowing for flexible configuration of the I/Os as either inputs or outputs. At power-on, the I/Os are configured as inputs, and the system master can change this configuration by writing to the I/O configuration bits.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 2.3 | - | 5.5 | V |
| Operating Temperature Range | -40 | - | 85 | °C |
| Standby Current Consumption | - | - | 1 | μA |
| I2C Bus Frequency | - | - | 400 | kHz |
| High-Level Output Current | - | - | -10 | mA |
| Low-Level Output Current | - | - | 25 | mA |
| ESD Protection | - | - | 2000 | V (Human-Body Model) |
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 Use of up to Eight Devices
- Polarity Inversion Register
- Latched Outputs With High-Current Drive Capability for Directly Driving LEDs
- ESD Protection Exceeds JESD 22 (2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model)
Applications
- Routers (Telecom Switching Equipment)
- Personal Computers
- Personal Electronics
- Industrial Automation Equipment
- Products with GPIO-Limited Processors
Q & A
- What is the operating voltage range of the PCA9555PWRG4?
The PCA9555PWRG4 operates within a voltage range of 2.3-V to 5.5-V.
- What is the maximum standby current consumption of the PCA9555PWRG4?
The maximum standby current consumption is 1 μA.
- What is the frequency of the I2C bus supported by the PCA9555PWRG4?
The PCA9555PWRG4 supports a 400-kHz fast I2C bus.
- How many devices can share the same I2C bus using the PCA9555PWRG4?
Up to eight devices can share the same I2C bus using the three hardware address pins.
- What is the purpose of the polarity inversion register in the PCA9555PWRG4?
The polarity inversion register allows the polarity of the input port register to be inverted between active high and active low operation.
- Can the PCA9555PWRG4 directly drive LEDs?
- What type of ESD protection does the PCA9555PWRG4 offer?
The PCA9555PWRG4 offers ESD protection exceeding JESD 22 standards, including 2000-V Human-Body Model, 200-V Machine Model, and 1000-V Charged-Device Model.
- How are the I/Os configured at power-on?
- Can the system master reset the PCA9555PWRG4?
- What is the purpose of the open-drain active-low interrupt output?
The open-drain active-low interrupt output is activated when any input state differs from its corresponding input port register state, indicating to the system master that an input state has changed.
