Overview
The PCA9554ADBR, produced by Texas Instruments, is a remote 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 power-supply voltage range of 2.3 V to 5.5 V, making it versatile for various applications. It features an open-drain active-low interrupt output and supports up to eight devices on the same I2C/SMBus, thanks to three hardware address pins (A0, A1, and A2). The PCA9554ADBR is pin-to-pin and I2C address compatible with the PCF8574, although software changes are necessary due to the enhancements in the PCA9554 series.
Key Specifications
| Specification | Value |
|---|---|
| Operating Power-Supply Voltage Range | 2.3 V to 5.5 V |
| I2C Bus Speed | 400 kHz |
| Number of I/O Pins | 8 |
| Interrupt Output Type | Open-Drain Active-Low |
| Package Types | SSOP (16), VQFN (16), TSSOP (16), SOIC, etc. |
| ESD Protection | 2000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model |
| I/O Configuration | Input or Output selection via I/O configuration bits |
| Polarity Inversion | Active high or active low via Polarity Inversion register |
Key Features
- I2C to Parallel Port Expander
- Open-Drain Active-Low Interrupt Output
- 5-V Tolerant I/Os
- 400-kHz Fast I2C Bus
- Three Hardware Address Pins for up to Eight Devices on the I2C/SMBus
- Input/Output Configuration Register
- Polarity Inversion Register
- Internal Power-On Reset
- Power-Up With All Channels Configured as Inputs
- No Glitch On Power Up
- Latched Outputs With High-Current Drive Capability for Directly Driving LEDs
- ESD Protection Exceeds JESD 22 Standards
Applications
The PCA9554ADBR is suitable for a variety of applications requiring remote I/O expansion, including:
- Automotive systems
- Industrial control systems
- Consumer electronics
- Medical devices
- Any system requiring additional I/O ports via an I2C interface
Q & A
- What is the operating voltage range of the PCA9554ADBR?
The PCA9554ADBR operates within a power-supply voltage range of 2.3 V to 5.5 V.
- How many devices can be connected on the same I2C/SMBus?
Up to eight devices can be connected on the same I2C/SMBus using the three hardware address pins (A0, A1, and A2).
- What is the purpose of the interrupt output?
The interrupt output is used to inform the microcontroller of any changes in the input state without continuous communication via the I2C bus.
- Can the PCA9554ADBR drive LEDs directly?
- What is the ESD protection level of the PCA9554ADBR?
The PCA9554ADBR has 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/O pins configured at power-up?
- Can the PCA9554ADBR be reset by the system master?
- Is the PCA9554ADBR compatible with other I2C devices?
- What are the package options available for the PCA9554ADBR?
- Can multiple PCA9554ADBR devices be used on the same I2C/SMBus?
