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 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

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.

1. For all available packages, see the orderable addendum at the end of the data sheet.