SK5222 - Ultra-Low Power Low Cost HID over I2C FlexMatrix™ Keyboard Encoder with 8x20 Keyboard Scan, 1 PWM Backlight and 4 LEDs Control, Field-Upgradable Bootloader

Overview

The SK5222 is an ultra-low power (0.1uA@3V) HID over I2C interface keyboard encoder ASIC with 1 PWM backlight and 4 LEDs control. The failure-safe bootloader design allows the SK5222 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 tablet / laptop / docking station / Instrument.

The SK5222 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 SK5222 provides one key-controlled and 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.

Features

• HID over I2C v1.0 interface
• Failure-safe Bootloader for firmware upgrade
• 8 x 20 matrix keyboard scan
• 1 PWM backlight brightness control
• Fn, FnLock and NumLock Impacted key support
• KeyLock for undetachable washable design
• Support macro keys like “Ctrl+Alt+Del”
• 350+ predefined keys and unlimited custom key definitions
• User-Programmable keyboard matrix
• Supports all HID over I2C commands: RESET, GET_REPORT, SET_REPORT, GET_IDLE, SET_IDLE, GET_PROTOCOL, SET_PROTOCOL, SET_POWER
• Advanced ghost key detection algorithm to maximize the key combination without additional diodes
• Support macro keys to generate like “Ctrl+Alt+Del”, or “Coke Cola”, “000” sequential string outputs
• 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
• Wireless Keyboard

SK5222 Pin Assignment

Technical Documents

Support Software

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™ Programmer

The software is used to download configuration matrix data and upgrade firmware to keyboard controller.

FlexMatrix™ Tester

The software is used to test all Sprintek USB and PS/2 keyboard products.