SK5210 - USB and HID over I2C Dual Interface User Programmable FlexMatrix™ Keyboard Encoder with 1 external PS/2, 1 PWM Backlight and 7 LEDs Control, Field-Upgradable Bootloader


The SK5210 is a low power USB and I2C dual interface keyboard encoder with 1 PWM backlight and 7 LEDs control. While the USB interface is connected to the main PC as normal keyboard, the secondary I2C interface can be used to communicate with a system embedded controller (EC) for EC to receive all user events and get full control of the system. It’s the best choice for customized keyboard design for tablet / PC / laptop / docking station / Instrument.

The SK5210 scans and encodes an 8-row by 20-column matrix. The key press events are translated to keyboard report. The encoder gets matrix information from on-chip matrix tables.

The backlight LED PWM brightness control and 7 LEDs can be controlled via the dual interfaces by commands or key press events.

The SK5210 provides an external PS/2 port that supports hot plug and hot swap of PS/2 devices such as touchpad, pointing stick, mouse including wheel mice, and keyboard. The host can send commands via SK5210 PS/2 command relay feature to the external PS/2 device to change default settings.


  • Full speed USB 2.0 HID and HID over I2C 1.0 dual interfaces with Bootloader for field upgrade
  • One external PS/2 interface to PS/2 device such as mouse, touchpad, pointing stick, and keyboard
  • 7 LEDs (4 shared with column scan pins)
  • 1 PWM backlight brightness control
  • FN key support
  • 8 x 20 matrix keyboard scan
  • User-Programmable keyboard matrix
  • 4 Matrix Tables for LFn, RFn cases, NumLock On/Off cases
  • Support macro keys to generate like international characters “€, ¥, ♫”, “Ctrl+Alt+Del”, or “Coke Cola”, “000” sequential string outputs
  • USB and I2C can have different scan code reports for the same key event
  • PS/2 command relay support
  • Advanced ghost key detection algorithm to maximize the key combination without additional diodes
  • HID over I2C interface supports commands: RESET GET_REPORT SET_REPORT SET_POWER
  • Built-in oscillator and digital circuit. No external crystal is needed
  • LQFP 48 pin package: 7x7mm 1.6 Max (LxWxH)
  • Low power consumption: 0.3uA (no key pressed under I2C only), 240uA (under USB suspend)
  • Operation voltage range: 3.0 to 5.5V
  • Industrial temperature range: -40°C to +85°C
  • Custom versions available in small and large quantities

Typical Applications

  • Tablet/Mobile Phone Docking Station Embedded Keyboard
  • Laptop/Netbook PC's Internal Keyboard
  • Instrument Control Panels
  • Tablet PC's Cover Keyboard
  • PS/2 to USB or I2C Protocol Converter
SK5210 Typical Application Diagram
Typical Application - Tablet Docking Station Keyboard with an Attached PS/2 Touchpad or Pointing Stick

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 data 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