Overview
The TCA6408A, produced by Texas Instruments, is a 16-pin device designed to provide 8-bits of general-purpose parallel input/output (I/O) expansion for the two-line bidirectional I2C bus (or SMBus) protocol. This device is versatile, operating with a power supply voltage range of 1.65 V to 5.5 V on both the I2C bus side and the P-port side, making it compatible with next-generation microprocessors and microcontrollers as well as components like LEDs that may operate at different voltage levels.
Key Specifications
| Specification | Value |
|---|---|
| Package | TSSOP (PW) with 16 pins |
| Operating Temperature Range | -40°C to 85°C |
| Operating Power-Supply Voltage Range | 1.65 V to 5.5 V |
| I2C Bus Clock Frequencies | 100 kHz (Standard-mode), 400 kHz (Fast-mode) |
| Standby Current Consumption | 1 µA |
| I/O Port Tolerance | 5-V Tolerant |
| Interrupt Output | Open-drain active-low interrupt (INT) |
| Reset Input | Active-low reset (RESET) |
| ESD Protection | 2000-V Human body model, 1000-V Charged-device model |
Key Features
- I2C to Parallel port expander
- Bidirectional voltage-level translation and GPIO expansion between 1.8-V, 2.5-V, 3.3-V, and 5-V I2C bus and P-ports
- Low standby current consumption of 1 µA
- 5-V Tolerant I/O ports
- Hardware address pin allows two TCA6408A devices on the same I2C/SMBus bus
- Active-low reset (RESET) input and open-drain active-low interrupt (INT) output
- Input and output configuration register and polarity inversion register
- Internal power-on reset and power up with all channels configured as inputs
- No glitch on power up and noise filter on SCL and SDA inputs
- Latched outputs with high-current drive capability for directly driving LEDs
- Latch-up performance exceeds 100 mA per JESD 78, class II
- Schmitt-trigger action for better switching noise immunity
Applications
The TCA6408A is designed to provide additional I/Os for various applications, including switches, sensors, push-buttons, LEDs, fans, and other components. It is particularly useful in scenarios where microprocessors and microcontrollers have limited I/O pins or where voltage-level translation is necessary between different components on the PCB.
Q & A
- What is the TCA6408A used for?
The TCA6408A is used as an I2C to Parallel port expander, providing 8-bits of general-purpose parallel input/output (I/O) expansion. - What is the operating power-supply voltage range of the TCA6408A?
The operating power-supply voltage range is from 1.65 V to 5.5 V. - What are the supported I2C bus clock frequencies?
The device supports both 100 kHz (Standard-mode) and 400 kHz (Fast-mode) clock frequencies. - Does the TCA6408A support voltage-level translation?
Yes, it allows bidirectional voltage-level translation and GPIO expansion between 1.8-V, 2.5-V, 3.3-V, and 5-V I2C bus and P-ports. - What is the standby current consumption of the TCA6408A?
The standby current consumption is 1 µA. - Can the TCA6408A drive LEDs directly?
Yes, it has latched outputs with high-current drive capability for directly driving LEDs. - What kind of ESD protection does the TCA6408A have?
The device has ESD protection exceeding 2000-V Human body model and 1000-V Charged-device model. - Can multiple TCA6408A devices be used on the same I2C/SMBus bus?
Yes, a hardware address pin allows two TCA6408A devices on the same I2C/SMBus bus. - What is the purpose of the internal power-on reset?
The internal power-on reset ensures that the device powers up with all channels configured as inputs and no glitch on power up. - Does the TCA6408A have noise filtering capabilities?
Yes, it has noise filters on SCL and SDA inputs and Schmitt-trigger action for better switching noise immunity.
