SK5103 - Medical Programmable USB FlexMatrix™ Keyboard Encoder IC with 9 AB Rotary Encoders, 16 Analog Sliders, 36 GPOs


The SK5103 is a USB keyboard designed for medical applications and other complex industrial applications with a user-programmable keyboard matrix, USB controlled GPOs, PWMs. The IC can be programmed to any keyboard with four matrix tables for FN and NUMLOCK (or RFN) cases, so the IC is the best choice for custom keyboard solution but with an off-the-shelf IC.

The SK5103 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 SK5103 scans 9 AB rotary encoder inputs then reports the encoders’ rotation events as an 8-bit counter. The SK5103 deploys Sprintek encoder debounce algorithm to work with any mechanical encoders reliably. The SK5103 samples 16 channel analog inputs and reports the 8-bit absolute values to PC after a change.

The SK5103 needn’t install special software device driver at PC side to support GPOs, PWMs, AB rotary encoders and analog sliders.


  • USB 2.0 full speed
  • User-Programmable keyboard matrix, scan code and macro keys
  • 4 sets of 8 x 20 keyboard matrix for Numlock(or RFN) and FN cases
  • Up to 255 Custom/Macro keys: generate “LCTRL+LALT+DEL”, “000” and “Diet Coke”
  • Interface 9 AB rotary encoders
  • Interface 16 analog sliders
  • Key-controlled and USB-controlled 36 GPOs via an external logic circuit
  • Key-controlled and USB-controlled 2 PWMs
  • No custom device driver is required
  • Support three FN control modes: Level, Toggle and Sticky
  • Support two delay keys
  • 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 56 pin package: 8x8mm 1.0 Max (LxWxH)
  • Low power consumption. 420uA (USB suspend) and 25 mA (USB operation)
  • 4.75 to 5.25V operating voltage
  • Commercial temperature range:0°C to +70°C
  • Custom versions available in small and large quantities

Typical Applications

  • Medical Keyboards (Ultrasound devices)
  • Industrial Keyboards

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
FlexMatrix™ Communicator for SK5103
The software is used to demostrate USB controlled features such as GPOs, PWMs and receive AB rotary encoder and analog slider reports.
FlexMatrix Editor Screenshot