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TCA6408

WITH INTERRUPT OUTPUT, RESET, AND CONFIGURATION REGISTERS

SCPS151C – FEBRUARY 2007 – REVISED JUNE 2007

ORDERING INFORMATION

ORDERABLE PART NUMBER

TOP-SIDE MARKING

QFN – RGT

Reel of 3000

TCA6408RGTR

ZWP

BGA – ZXY (Pb-free)

Reel of 2500

TCA6408ZXYR

PH408

–40

°C to 85°C

Tube of 70

TCA6408PW

TSSOP – PW

PH408

Reel of 2000

TCA6408PWR

(1)

For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI

on the SDA/SCL side. This allows the TCA6408 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 TCA6408 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 TCA6408 in the event of a timeout or other improper operation by asserting a

state machine. The RESET pin causes the same reset/initialization to occur without depowering the part.

The TCA6408 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 device P port outputs have high-current sink capabilities for directly driving LEDs while consuming low

device current.

2

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