SK5120 - Low Power USB Programmable FlexMatrix™ Keyboard Encoder with an External PS/2 port and KeyMouse Support


The SK5120 is a low power USB keyboard encoder with a user-programmable keyboard matrix. The IC can be programmed to any keyboard with four matrix tables for FN and NUMLOCK cases, so the IC is the best choice for custom keyboard solution but with an off-the-shelf IC.

The IC operates under low voltage 3.3V and can interface a low voltage (3V) PS/2 mouse such as touchpad to minimize the system power consumption.

The SK5120 scans and encodes an 8-row by 18-column matrix. The key press events are translated to keyboard and mouse report. The encoder gets matrix information from on-chip flash matrix table. Sprintek provides Windows® application FlexMatrix Editor and Programmer software to edit, download and upload the matrix table.

The SK5120 provides an external PS/2 port that supports hot plug and hot swap of PS/2 mouse including wheel mouse, and keyboard devices. It is ideal to work with touchpad or pointing stick PS/2 mouse encoder for new architecture laptop/netbook computers.


  • USB 2.0 full speed
  • User-Programmable keyboard matrix
  • 4 sets of 8 x 18 keyboard matrix for Numlock and FN cases
  • Up to 255 Custom/Macro keys: generate “LCTRL+LALT+DEL” or “000” keys
  • Key-controlled external PS/2 device lock feature without driver required
  • Built-in 8 direction KeyMouse
  • Support PS/2 command pass-through via USB port
  • Support one external PS/2 to interface an PS/2 mouse or keyboard
  • Key-controlled 3 general purpose output(GPO), 1 state control output(SCO), Blackout control
  • Support three FN control modes: Level, Toggle and Sticky
  • Supports USB selective suspend and remote wakeup
  • Built-in oscillator and digital circuit. No external crystal is needed
  • Windows® application to design keyboard matrix
  • Low profile QFN 48 pin package: 7x7mm 1.0 Max (LxWxH)
  • Low power consumption: 235 uA (USB suspend) and 4.6 mA (USB operation)
  • Operating voltage: 3.15 to 3.45V and 4.35 to 5.25V (pin selectable)
  • Commercial range: 0°C to +70°C
  • Custom versions available in small and large quantities

Typical Applications

  • Netbook PCs
  • Notebook PCs
  • Industrial Keyboard
  • Point-of-sale (POS) terminals
  • Portable devices
SK5120 Typical Application Diagram
Typical Application - USB 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