Overview
The PCA9554DBR, produced by Texas Instruments, is an 8-bit I2C and SMBus I/O expander designed to provide general-purpose remote I/O expansion for most microcontroller families. This device operates within a voltage range of 2.3V to 5.5V and is compatible with both I2C and SMBus protocols. It features an open-drain interrupt output and configuration registers, allowing for flexible I/O configuration and interrupt handling. The PCA9554DBR is pin-to-pin and I2C address compatible with the PCF8574, although software changes may be necessary due to the enhancements in the PCA9554.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage Range | 2.3 | - | 5.5 | V |
| Input Voltage Range | -0.5 | - | 6 | V |
| Output Voltage Range | -0.5 | - | 6 | V |
| Continuous Output Low Current | - | - | 50 | mA |
| Continuous Output High Current | - | - | -50 | mA |
| Supply Current (Operating Mode) | 20 | 65 | 175 | μA (at 2.7V, fscl = 400 kHz) |
| Storage Temperature Range | -65 | - | 150 | °C |
Key Features
- 8-bit I/O expander for I2C and SMBus interfaces.
- Operating voltage range: 2.3V to 5.5V.
- Open-drain interrupt output for indicating input state changes.
- Configuration, Input, Output, and Polarity Inversion registers.
- High-current drive capability for directly driving LEDs.
- Low current consumption.
- Hardware address pins (A0, A1, A2) for programming and varying the fixed I2C address, allowing up to eight devices on the same I2C/SMBus.
- Power-on reset feature to initialize the device to its default state.
Applications
- Personal computers and personal electronics (e.g., gaming consoles).
- Industrial automation.
- Telecom switching equipment and routers.
- Products with GPIO-limited processors.
- General-purpose remote I/O expansion for various microcontroller families).
Q & A
- What is the operating voltage range of the PCA9554DBR?
The PCA9554DBR operates within a voltage range of 2.3V to 5.5V).
- What is the purpose of the interrupt output on the PCA9554DBR?
The interrupt output is used to indicate to the system master that an input state has changed).
- How many PCA9554DBR devices can be connected on the same I2C/SMBus?
Up to eight PCA9554DBR devices can be connected on the same I2C/SMBus using the hardware address pins (A0, A1, A2)).
- What is the maximum continuous output low current of the PCA9554DBR?
The maximum continuous output low current is 50 mA).
- Can the PCA9554DBR be reset to its default state?
- Is the PCA9554DBR compatible with other Texas Instruments devices?
The PCA9554DBR is pin-to-pin and I2C address compatible with the PCF8574, although software changes may be necessary).
- What is the storage temperature range for the PCA9554DBR?
The storage temperature range is -65°C to 150°C).
- Does the PCA9554DBR support both standard and fast I2C modes?
- What is the purpose of the configuration registers in the PCA9554DBR?
The configuration registers allow the system master to configure the I/Os as either inputs or outputs and to set the polarity of the input port register).
- Can the PCA9554DBR drive LEDs directly?
