Date: 22/10/2009
I2C controlled keypad/keyboard scan device from TI supporting QWERTY
TI has introduced the TCA8418, a key scan device with integrated ESD protection that generate an interrupt output signal using a three-key combination such as CTRL-ALT-DEL, which frees up the processor from scanning the keys for presses and releases, saving power and bandwidth. The TCA8418 is suitable for the applications such as smartphones, multimedia handsets, personal digital assistants (PDA) and mobile Internet devices (MID).
The key controller includes an oscillator that debounces at 50 us and maintains a 10-byte FIFO of key-press and key-release events, which can store up to 10 keys with overflow wrap capability. An interrupt (/INT) output can be configured to alert key presses and releases, either as they occur or at maximum rate.
The key features and benefits of the TCA8418 are,
Operating input voltage ranges from 1.65 V to 3.6 V
Supports QWERTY keypad operation plus GPIO expansion
18 GPIOs can be configured into eight inputs and ten outputs to support an 8 × 10 keypad array (80 buttons) through the I2C interface
3 ľA of low standby (Idle) current consumption extends battery life in portable devices
Polling current drain 70 ľA for one key pressed
The TCA8418 is also ideal for usage with processors that have limited GPIOs.
Package: 4 mm x 4 mm QFN package
Price: Each $1.20 for 1k pieces
Availability: Now
A small, 2 mm x 2 mm WCSP version will be available in 1Q2010.
For more details visit www.ti.com
Editorial Product Rating: Average