Overview
The TCA9554DBQR, produced by Texas Instruments, is a low-voltage 8-bit I2C and SMBus I/O expander. This device provides 8 bits of general-purpose parallel input and output (I/O) expansion for the two-line bidirectional I2C bus (or SMBus) protocol. It operates with a power supply voltage ranging from 1.65 V to 5.5 V and supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. The TCA9554 is particularly useful when additional I/Os are needed for devices such as switches, sensors, push-buttons, LEDs, fans, and other similar peripherals.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Operating Power-Supply Voltage | Range | 1.65 V to 5.5 V |
| I2C Clock Frequency | Standard-mode / Fast-mode | 100 kHz / 400 kHz |
| Package Type | SSOP (16 pins) | |
| Operating Temperature | Range | -40°C to 85°C |
| Address Pins | Number of devices supported | 3 (A0, A1, A2) - up to 8 devices |
| Interrupt Output | Type | Open-drain active-low |
| I/O Ports | Configuration | 5-V tolerant, push-pull design |
| Standby Current Consumption | Low | |
| Thermal Resistance (Junction-to-Ambient) | 122 °C/W (SSOP) |
Key Features
- Interrupt Generation: An interrupt is generated on the INT pin whenever an input port changes state.
- Hardware Addressable: Three hardware selectable address pins (A0, A1, A2) allow up to eight TCA9554 devices on the same I2C bus.
- Internal Power-On Reset: The device can be reset to its default state by cycling the power supply.
- Input and Output Configuration Register: Allows for flexible configuration of I/O ports.
- Polarity Inversion Register: Enables polarity inversion of the I/O ports.
- Low Standby Current Consumption: Minimizes power consumption in standby mode.
- Power-Up Configuration: All channels are configured as inputs on power-up.
- No Glitch on Power Up: Ensures clean power-up without glitches.
- Noise Filter on SCL/SDA Inputs: Enhances reliability by filtering noise on the I2C bus.
- Latched Outputs with High-Current Drive: Capable of directly driving LEDs with high current.
- ESD Protection: Exceeds JESD 22 – 2000-V Human-Body Model and 1000-V Charged-Device Model.
Applications
- Servers and Routers: Ideal for telecom switching equipment and data center applications.
- Personal Computers: Useful in expanding I/O capabilities in PC systems.
- Personal Electronics: Suitable for gaming consoles and other consumer electronics.
- Industrial Automation: Enhances I/O capabilities in industrial control systems.
- Products with GPIO-Limited Processors: Provides additional I/Os for processors with limited GPIO resources.
Q & A
- What is the operating voltage range of the TCA9554DBQR?
The TCA9554DBQR operates with a power supply voltage ranging from 1.65 V to 5.5 V.
- What are the supported I2C clock frequencies for the TCA9554DBQR?
The device supports both 100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies.
- How many devices can be connected on the same I2C bus using the TCA9554DBQR?
Up to eight TCA9554 devices can be connected on the same I2C bus using the three hardware selectable address pins (A0, A1, A2).
- What type of interrupt output does the TCA9554DBQR have?
The TCA9554DBQR has an open-drain active-low interrupt output.
- How does the TCA9554DBQR handle power-on reset?
The device can be reset to its default state by cycling the power supply, causing a power-on reset.
- What is the thermal resistance (junction-to-ambient) of the TCA9554DBQR in SSOP package?
The thermal resistance (junction-to-ambient) is 122 °C/W for the SSOP package.
- Does the TCA9554DBQR have ESD protection?
Yes, the TCA9554DBQR exceeds JESD 22 – 2000-V Human-Body Model and 1000-V Charged-Device Model for ESD protection.
- What is the standby current consumption of the TCA9554DBQR?
The TCA9554DBQR has low standby current consumption.
- Can the TCA9554DBQR directly drive LEDs?
Yes, the TCA9554DBQR has latched outputs with high-current drive capability, making it suitable for directly driving LEDs.
- What types of applications is the TCA9554DBQR suitable for?
The TCA9554DBQR is suitable for servers, routers, personal computers, personal electronics, industrial automation, and products with GPIO-limited processors.
