SK5223 - Ultra-Low Power, User-Programmable SMBus (I2C) FlexMatrix™ Keyboard Controller with 8x20 Scan, PWM Backlight, Upgradable Bootloader


The SK5223 is an ultra-low power (0.1uA@3V) SMBus v1.1 (or I2C) interface keyboard encoder ASIC with 1 PWM backlight and 4 LEDs control. The failure-safe bootloader design allows the SK5223 to still have full keyboard functions even when any interruption failure happens during the firmware update. It’s the best choice for customized keyboard design for battery powered notebook / netbook / tablet / docking station / Instrument / IO expander. The SK5223 deploys Sprintek FlexMatrix™ technology for users to upgrade firmware in the field.

The SK5223 scans and encodes an 8-row by 20-column matrix. The key press events are translated to keyboard event report.

The SK5223 provides command-controlled PWM for backlight LED PWM brightness control. An IO pin BLEN can be used to turn off the backlight circuit totally. When BLEN is used, the keyboard scan will be 8-row by 19-columns.


  • SMBus v1.1 (or I2C) interface with get UDID
  • PEC CRC enabled communication
  • Failure-safe Bootloader for firmware upgrade
  • 8 x 20 matrix keyboard scan
  • 1 PWM backlight brightness control
  • 4 Keyboard LEDs
  • Advanced ghost key detection algorithm to maximize the key combination without additional diodes
  • Built-in oscillator and digital circuit. No external crystal is needed
  • QFN 46 pin package: 6.5x4.5mm 0.9 Max (LxWxH)
  • or LQFP 48 pin package: 7x7mm 1.6 Max (LxWxH)
  • Low power consumption: @ 3V: 0.1uA (no key pressed) 110uA (1 key) 50uA (inc per Key)
  • Operation voltage range: 2.2 to 5.5V
  • Industrial temperature range: -40°C to +85°C
  • Custom versions available in small and large quantities

Typical Applications

  • Laptop/Netbook PC's Internal Keyboard
  • Tablet PC's Cover Keyboard
  • Tablet/Mobile Phone Docking Station Embedded Keyboard
  • Instrument Control Panels
  • I/O Expander
  • Wireless keyboards
SK5223 Pin Assignment
SK5223 Pin Assignment

Support Software

Click here to download these tools.
FlexMatrix™ Editor
The software is used to generate configuration data (keyboard matrix, macro key definition, scan code definition and other feature control parameters) into a binary file.
FlexMatrix Editor Screenshot
FlexMatrix™ Programmer
The software is used to download configuration matrix data and upgrade firmware to keyboard controller.
FlexMatrix Programmer Screenshot
FlexMatrix™ Tester
The software is used to test all Sprintek USB and PS/2 keyboard products.
FlexMatrix Tester Screenshot