Low-Voltage 8-Bit I2C and SMBus I/O Expander - TCA6408A

TCA6408A (ACTIVE)

Low-Voltage 8-Bit I2C and SMBus I/O Expander



TCA6408A Free Sample Package Options

TCA6408A Low-Voltage 8-Bit I2C and SMBus I/O Expander

The TCA6408A Low-voltage 8-Bit I2C and SMBus I/O expander allows bidirectional voltage-level translation and GPIO expansion from 1.8V-5V on the P-port side to 1.8V-5V on the SDA/SCL side.

6.4mm x 5mm 3mm x 3mm 2.6mm x 1.8mm

Features

  • Operating Power-Supply Voltage Range of
    1.65 V to 5.5 V
  • Allows Bidirectional Voltage-Level Translation and
    GPIO Expansion Between
    • 1.8-V SCL/SDA and 1.8-V, 2.5-V,
      3.3-V, or 5-V P Port
    • 2.5-V SCL/SDA and 1.8-V, 2.5-V,
      3.3-V, or 5-V P Port
    • 3.3-V SCL/SDA and 1.8-V, 2.5-V,
      3.3-V, or 5-V P Port
    • 5-V SCL/SDA and 1.8-V, 2.5-V,
      3.3-V, or 5-V P Port
  • I2C to Parallel Port Expander
  • Low Standby Current Consumption of 1 µA
  • Schmitt-Trigger Action Allows Slow Input Transition and
    Better Switching Noise Immunity at the SCL and SDA Inputs
    • Vhys = 0.18 V Typ at 1.8 V
    • Vhys = 0.25 V Typ at 2.5 V
    • Vhys = 0.33 V Typ at 3.3 V
    • Vhys = 0.5 V Typ at 5 V
  • 5-V Tolerant I/O Ports
  • Active-Low Reset (RESET) Input
  • Open-Drain Active-Low Interrupt (INT) Output
  • 400-kHz Fast I2C Bus
  • Input/Output Configuration Register
  • Polarity Inversion Register
  • Internal Power-On Reset
  • Power Up With All Channels Configured as Inputs
  • No Glitch On Power Up
  • Noise Filter on SCL/SDA Inputs
  • Latched Outputs With High-Current Drive Maximum
    Capability for Directly Driving LEDs
  • Latch-Up Performance Exceeds 100 mA Per JESD 78,
    Class II
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 1000-V Charged-Device Model (C101)

DESCRIPTION/ORDERING INFORMATION

This 8-bit I/O expander for the two-line bidirectional bus (I2C) is designed to provide general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL) and serial data (SDA)].

The major benefit of this device is its wide VCC range. It can operate from 1.65-V to 5.5-V on the P-port side and on the SDA/SCL side. This allows the TCA6408A to interface with next-generation microprocessors and microcontrollers on the SDA/SCL side, where supply levels are dropping down to conserve power. In contrast to the dropping power supplies of microprocessors and microcontrollers, some PCB components such as LEDs remain at a 5-V power supply.

The bidirectional voltage-level translation in the TCA6408A is provided through VCCI. VCCI should be connected to the VCC of the external SCL/SDA lines. This indicates the VCC level of the I2C bus to the TCA6408A. The voltage level on the P port of the TCA6408A is determined by VCCP.

The TCA6408A consists of one 8-bit Configuration (input or output selection), Input, Output, and Polarity Inversion (active high) Register. At power on, the I/Os are configured as inputs. However, the system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding Input or Output Register. The polarity of the Input Port Register can be inverted with the Polarity Inversion Register. All registers can be read by the system master.

The system master can reset the TCA6408A in the event of a timeout or other improper operation by asserting a low in the RESET input. The power-on reset puts the registers in their default state and initializes the I2C/SMBus state machine. The RESET pin causes the same reset/initialization to occur without depowering the part.

The TCA6408A open-drain interrupt (INT) output is activated when any input state differs from its corresponding Input Port Register state and is used to indicate to the system master that an input state has changed.

INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I2C bus. Thus, the TCA6408A can remain a simple slave device.

The device P-port outputs have high-current sink capabilities for directly driving LEDs while consuming low device current.

One hardware pin (ADDR) can be used to program and vary the fixed I2C address and allow up to two devices to share the same I2C bus or SMBus.

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Parametrics Compare all products in I2C IO Expander

 
Voltage Nodes (V)
Approx. Price (US$)
Pin/Package
Operating Temperature Range (C)
Max Frequency (kHz)
I2C Address
# of I/Os
Rating
Special Features
TCA6408A PCA6107 TCA6416A TCA6424A TCA7408
1.8
2.7
3.3
3.6
5    
  1.8
2.7
3.3
3.6
5    
1.8
2.7
3.3
3.6
5    
1.8
2.7
3.3
3.6
5    
0.60 | 1ku     0.90 | 1ku     0.79 | 1ku     0.95 | 1ku     0.85 | 1ku    
16QFN
16TSSOP
16UQFN    
18SOIC     24BGA MICROSTAR JUNIOR
24TSSOP
24WQFN    
32UQFN     16uCSP    
-40 to 85     -40 to 85     -40 to 85     -40 to 85     -40 to 85    
400       400     400     400    
0100 00x       0100 00x     0100 01x     0100 00x    
8     8     16     24     8    
Catalog     Catalog     Catalog     Catalog     Catalog    
5V Tolerant I/O
Configuration Registers
Interrupt Driven
Interrupt Output
Low Power
Low Voltage
Push-Pull I/O Type
Reset Input    
  5V Tolerant I/O
Configuration Registers
Interrupt Driven
Interrupt Output
Low Power
Low Voltage
Push-Pull I/O Type
Reset Input    
5V Tolerant I/O
Configuration Registers
Interrupt Driven
Interrupt Output
Low Power
Low Voltage
Push-Pull I/O Type
Reset Input    
Configuration Registers
Interrupt Driven
Interrupt Output
Low Power
Low Voltage
Programmable Pull-Up/Pull-Down
Push-Pull I/O Type
Reset Input    
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