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  • TCA8418E I2C Controlled Keypad Scan IC With Integrated ESD Protection

    • SCPS222C May   2010  – October 2015 TCA8418E

      PRODUCTION DATA.  

  • CONTENTS
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  • TCA8418E I2C Controlled Keypad Scan IC With Integrated ESD Protection
  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics
    6. 6.6  I2C Interface Timing Requirements
    7. 6.7  Reset Timing Requirements for Standard Mode, Fast Mode, Fast Mode Plus (FM+) I2C Bus
    8. 6.8  Switching Characteristics for Standard Mode, Fast Mode, Fast Mode Plus (FM+) I2C Bus
    9. 6.9  Keypad Switching Characteristics for Standard Mode, Fast Mode, Fast Mode Plus (FM+) I2C Bus
    10. 6.10 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Key Events
        1. 8.3.1.1 Key Event Table
        2. 8.3.1.2 General Purpose Input (GPI) Events
        3. 8.3.1.3 Key Event (FIFO) Reading
        4. 8.3.1.4 Key Event Overflow
      2. 8.3.2 Keypad Lock/Unlock
      3. 8.3.3 Keypad Lock Interrupt Mask Timer
      4. 8.3.4 Control-Alt-Delete Support
      5. 8.3.5 Interrupt Output
        1. 8.3.5.1 50-µs Interrupt Configuration
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-On Reset (POR)
      2. 8.4.2 Powered (Key Scan Mode)
        1. 8.4.2.1 Idle Key Scan Mode
        2. 8.4.2.2 Active Key Scan Mode
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
      2. 8.5.2 Bus Transactions
        1. 8.5.2.1 Writes
        2. 8.5.2.2 Reads
    6. 8.6 Register Maps
      1. 8.6.1 Device Address
      2. 8.6.2 Control Register and Command Byte
        1. 8.6.2.1  Configuration Register (Address 0x01)
        2. 8.6.2.2  Interrupt Status Register, INT_STAT (Address 0x02)
        3. 8.6.2.3  Key Lock and Event Counter Register, KEY_LCK_EC (Address 0x03)
        4. 8.6.2.4  Key Event Registers (FIFO), KEY_EVENT_A-J (Address 0x04-0x0D)
        5. 8.6.2.5  Keypad Lock1 to Lock2 Timer Register, KP_LCK_TIMER (Address 0x0E)
        6. 8.6.2.6  Unlock1 and Unlock2 Registers, UNLOCK1/2 (Address 0x0F-0x10)
        7. 8.6.2.7  GPIO Interrupt Status Registers, GPIO_INT_STAT1-3 (Address 0x11-0x13)
        8. 8.6.2.8  GPIO Data Status Registers, GPIO_DAT_STAT1-3 (Address 0x14-0x16)
        9. 8.6.2.9  GPIO Data Out Registers, GPIO_DAT_OUT1-3 (Address 0x17-0x19)
        10. 8.6.2.10 GPIO Interrupt Enable Registers, GPIO_INT_EN1-3 (Address 0x1A-0x1C)
        11. 8.6.2.11 Keypad or GPIO Selection Registers, KP_GPIO1-3 (Address 0x1D-0x1F)
        12. 8.6.2.12 GPI Event Mode Registers, GPI_EM1-3 (Address 0x20-0x22)
        13. 8.6.2.13 GPIO Data Direction Registers, GPIO_DIR1-3 (Address 0x23-0x25)
        14. 8.6.2.14 GPIO Edge/Level Detect Registers, GPIO_INT_LVL1-3 (Address 0x26-0x28)
        15. 8.6.2.15 Debounce Disable Registers, DEBOUNCE_DIS1-3 (Address 0x29-0x2B)
        16. 8.6.2.16 GPIO Pullup Disable Register, GPIO_PULL1-3 (Address 0x2C-0x2E)
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Ghosting Considerations
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Designing the Hardware Layout
        2. 9.2.2.2 Configuring the Registers
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Community Resources
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information
  14. IMPORTANT NOTICE
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DATA SHEET

TCA8418E I2C Controlled Keypad Scan IC With Integrated ESD Protection

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.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TCA8418E DSBGA (25) 2.00 mm × 2.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

TCA8418E MainGraphic.gif
Only 7 GPIOs are shown out of the full 18 GPIOs

4 Revision History

Changes from B Revision (September 2010) to C Revision

  • Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo

Changes from A Revision (June 2010) to B Revision

  • Replaced ±8-kV with ±15-kV Human Body Model High Voltage ESD (GPIO lines)Go
  • Replaced all TBD valuesGo

5 Pin Configuration and Functions

YFP Package
25-Pin DSBGA
Laser Marking and Bump Views
TCA8418E po_yfp_cps215.gif

Pin Assignments

E INT GND COL5 COL0 ROW3
D SCL COL9 COL4 ROW0 ROW4
C SDA COL8 COL3 ROW1 ROW5
B VCC COL7 COL2 CAD_INT ROW6
A RESET COL6 COL1 ROW2 ROW7
5 4 3 2 1

Pin Functions

PIN I/O DESCRIPTION
NO. NAME
A1 ROW7 I/O GPIO or row 7 in keypad matrix. If unused, connect to VCC through a pullup resistor.
A2 ROW2 I/O GPIO or row 2 in keypad matrix. If unused, connect to VCC through a pullup resistor.
A3 COL1 I/O GPIO or column 1 in keypad matrix. If unused, connect to VCC through a pullup resistor.
A4 COL6 I/O GPIO or column 6 in keypad matrix. If unused, connect to VCC through a pullup resistor.
A5 RESET I Active-low reset input. Connect to VCC through a pullup resistor, if no active connection is used.
B1 ROW6 I/O GPIO or row 6 in keypad matrix
B2 CAD_INT O Active-low interrupt hardware output for 3-key simultaneous press-event. Open drain structure. Connect to VCC through a pullup resistor.
B3 COL2 I/O GPIO or column 2 in keypad matrix. If unused, connect to VCC through a pullup resistor.
B4 COL7 I/O GPIO or column 7 in keypad matrix. If unused, connect to VCC through a pullup resistor.
B5 VCC - Supply voltage of 1.65 V to 3.6 V
C1 ROW5 I/O GPIO or row 5 in keypad matrix. If unused, connect to VCC through a pullup resistor.
C2 ROW1 I/O GPIO or row 1 in keypad matrix. If unused, connect to VCC through a pullup resistor.
C3 COL3 I/O GPIO or column 3 in keypad matrix. If unused, connect to VCC through a pullup resistor.
C4 COL8 I/O GPIO or column 8 in keypad matrix. If unused, connect to VCC through a pullup resistor.
C5 SDA I/O Serial data bus. Connect to VCC through a pullup resistor.
D1 ROW4 I/O GPIO or row 4 in keypad matrix. If unused, connect to VCC through a pullup resistor.
D2 ROW0 I/O GPIO or row 0 in keypad matrix. If unused, connect to VCC through a pullup resistor.
D3 COL4 I/O GPIO or column 4 in keypad matrix. If unused, connect to VCC through a pullup resistor.
D4 COL9 I/O GPIO or column 9 in keypad matrix. If unused, connect to VCC through a pullup resistor.
D5 SCL I Serial clock bus. Connect to VCC through a pullup resistor.
E1 ROW3 I/O GPIO or row 3 in keypad matrix. If unused, connect to VCC through a pullup resistor.
E2 COL0 I/O GPIO or column 0 in keypad matrix. If unused, connect to VCC through a pullup resistor.
E3 COL5 I/O GPIO or column 5 in keypad matrix. If unused, connect to VCC through a pullup resistor.
E4 GND – Ground
E5 INT O Active-low interrupt output. Open drain structure. Connect to VCC through a pullup resistor.

 
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