TCA8418E Datasheet, PDF (1/35 Pages) Texas Instruments – I2C CONTROLLED KEYPAD SCAN IC WITH INTEGRATED ESD PROTECTION

TCA8418E
www.ti.com
SCPS222B – MAY 2010 – REVISED SEPTEMBER 2010
I²C CONTROLLED KEYPAD SCAN IC WITH INTEGRATED ESD PROTECTION
Check for Samples: TCA8418E
FEATURES
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• Operating Power-Supply Voltage Range of
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)
• ESD Protection Exceeds JESD 22 on non-GPIO
pins
– 2000-V Human Body Model (A114-A)
– 1000-V Charged Device Model (C101)
• ±15kV Human Body Model High Voltage ESD
(GPIO lines)
• Low Standby (Idle) Current Consumption: 3 mA
• Polling Current Drain 70 mA for One Key
Pressed
• 10 Byte FIFO to Store 10 Key Presses and
Releases
• Supports 1-MHz Fast Mode Plus I²C Bus
• Open-Drain Active-Low Interrupt Output,
Asserted when Key is Pressed and Key is
Released
• Minimum Debounce Time of 50 ms
• Schmitt-Trigger Action Allows Slow Input
Transition and Better Switching Noise
Immunity at the SCL and SDA Inputs: Typical
V_hys at 1.8 V is 0.18 V
• Latch-Up Performance Exceeds 200 mA Per
JESD 78, Class II
• Very Small Package
– WCSP (YFP): 2 mm × 2 mm; 0.4 mm pitch
APPLICATIONS
• Smart Phones
• PDAs
• GPS Devices
• MP3 Players
• Digital Cameras
DESCRIPTION/ORDERING INFORMATION
The TCA8418E is a keypad scan device with
integrated ESD protection. It can operate from 1.65 V
to 3.6 V and has 18 general purpose inputs/outputs
(GPIO) that can be used to support up to 80 keys via
the I²C interface [serial clock (SCL), serial data
(SDA)].
The key controller includes an oscillator that
debounces at 50 ms and maintains a 10 byte FIFO of
key-press and 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. Also, for the YFP package, a CAD_INT pin is
included to indicate the detection of CTRL-ALT-DEL
(i.e., 1, 11, 21) key press action.
The major benefit of this device is it frees up the
processor from having to scan the keypad for presses
and releases. This provides power and bandwidth
savings. The TCA8418E is also ideal for usage with
processors that have limited GPIOs.
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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.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated