Part Number : TCA8424
Function : Low-Voltage 8x16 Keyboard Scanner with HID over I2C Compliant Interface
Package : PLCC 40 Pin Type
Maker : Texas Instruments
Pinouts : 
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.
The device generates INPUT reports of standard 8-byte length with the 1st byte being the modifier byte. After the 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.
Datasheet PDF Download :
Others datasheet of same file : TCA-8424,TCA8424RHAR