Thermal Pad

SIZE AND SHAPE

SHOWN ON SEPARATE SHEET

1

32

32X

0.30

0.18

0.10 M C A B

0.50

3.50

4X

32X

0.50

0.30

TCA8424

www.ti.com

SCDS341 – MARCH 2013

Low-Voltage 8x16 Keyboard Scanner with HID over I2C Compliant Interface

Check for Samples: TCA8424

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FEATURES

•

Operating Power-Supply Voltage Range of

•

ESD Protection Exceeds JESD 22

1.65V to 3.6V

–

1000-V Human-Body Model (A114-A)

•

Supports FM+ I2C Operation up to 1MHz

•

Can Support up to 128 (8x16) Key Scan

RHB 5mmx5mm

RSM 4mmx4mm

•

Internal Power-On-Reset

PREVIEW

•

Open Drain Open Drain Active Low INT Output

•

Noise Filter on SCL/SDA and Inputs

•

Open Drain Outputs Can Sink up to 12mA

Current for LED

•

Hardware Coded HID and REPORT Descriptors

•

Available With Preprogrammed Keyboard Map

•

Software Reset per HID Over I2C Standard

•

Internal Pull-up Resistors Make

Implementation Easy With no Need for

External Components

•

HID Over I2C Commands Supported

–

RESET

RHA 6mm x 6mm

–

GET REPORT

–

SET REPORT

–

SET POWER

•

Fixed Length 8-byte INPUT Report can Detect

up to 6 Simultaneous Key Presses Excluding

Modifiers (CTRL, ALT, SHIFT)

•

INPUT Report Generated on Key Press and

Release

•

Latch-Up Performance Exceeds 100 mA Per

JESD 78, Class II

DESCRIPTION

This 128 key scan device is specifically targeted towards end equipment that runs on Windows 8 operating

system. The device is fully compliant with the HID over I2C specification defined (ver 1.0) defined by Microsoft.

The HID and report descriptors are hard coded into the device so that they don’t need to be programmed at

production. The device also comes with a preprogrammed keyboard map that is compatible with most standard

laptop/notebook keyboards. However, the device also available without a pre-programmed keyboard, so that any

keyboard map may be written into it at production.

keyboard map is programmed into the device it automatically recognizes the row/column location of the modifier

keys based on their usage code. It is capable of detecting and reporting up to six simultaneous key presses plus

eight modifiers. It generates an input report on each key press and each key release.

The device also supports LED indicators that are standard on a keyboard. Different variations support 2,4 or 8

LED outputs. Each output has open drain architecture and is capable of sinking up to 12mA of current. The LEDs

are controlled by a standard OUTPUT report as described in the HID over I2C standard.

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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright © 2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.