1 Features
• Operating Power-Supply Voltage Range of 1.65-V
to 3.6-V
• ±15-kV Human Body Model High Voltage ESD
(GPIO lines)
• Supports 80 Buttons With Use of 18 GPIOs
• Supports QWERTY Keypad Operation Plus GPIO
Expansion
• Low Standby (Idle) Current Consumption: 3 μA
• Supports 1-MHz Fast Mode Plus I2C Bus
• 10-Byte FIFO to Store 10 Key Presses and
Releases
• Open-Drain Active-Low Interrupt Output
• Integrated Debounce Time of 50 μs
• Schmitt-Trigger Action Allows Slow Input
Transition and Better Switching Noise Immunity at
the SCL and SDA Inputs: Typical Vhys 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

2 Applications
• Smart Phones
• Tablets
• HMI Panels
• GPS Devices
• MP3 Players
• Digital Cameras

3 Description
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.
The TCA8418E saves power and bandwidths since it
handles the keypad scanning algorithms. The
TCA8418E is also ideal for usage with processors
that have limited GPIOs.
The key controller debounces inputs 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. A CAD_INT pin is included to indicate
the detection of CTRL-ALT-DEL (essentially, 1, 11,
21) key press action.