BS2824/BS2854/BS2868 -- Touch Key MCU (Restricted Products)

General Description

The BS2824/BS2854/BS2868 are a series of 8-bit high performance, RISC architecture touch key microcontrollers specifically designed for a wide range of touch key applications. The usual Holtek microcontroller features of low power consumption, I/O flexibility, timer functions, oscillator options, power down and wake-up functions, watchdog timer and  low voltage reset, combine to provide devices with a huge range of functional options while still maintaining a high level of cost effectiveness. The fully integrated system oscillator HIRC, which requires no external components and which has three frequency selections, opens up a huge range of new application possibilities for these devices.

The special features of the BS2824/BS2854/BS2868 devices lie in their touch key functions which can detect human body contact using external touch pads. The high level of device integration enable full touch key applications to be implemented with a minimum number of external components. The devices are equipped with a One-line serial interface to allow easy communication for device setup and for touch pin monitoring and setup purposes.

Special internal circuitry is also employed to ensure excellent power noise rejection to reduce the possibility of false detections, increasing the touch switch application reliability under adverse environmental conditions. With  auto-calibration, low standby current and a choice of wake-up features, this touch key MCU device range provides a simple, reliable and highly cost-effective means of implementing touch switches in a wide variety of user applications.

Features

Microcontroller Features

  • Operating voltage:
    fSYS= 4MHz: 2.2V~5.5V
    fSYS= 8MHz: 3.0V~5.5V
    fSYS= 12MHz: 4.5V~5.5V
  • Up to 0.33us instruction cycle with 12MHz system clock at VDD=5V
  • Multi Operational Modes - Normal/Slow/Idle/Sleep and wake-up functions to reduce power consumption
  • Oscillator types:
    External high freuency Crystal -- HXT
    External RC -- ERC
    Internal RC -- HIRC
    External low frequency crystal -- LXT
  • Fully integrated internal 4MHz, 8MHz and 12MHz oscillator requires no external components
  • Up to two 8-bit Timer/Event Counters
  • Two channel 8-bit PWM for BS2868
  • Up to 31 bidirectional I/O lines
  • Watchdog Timer function
  • Software controlled LCD driver
  • Low voltage reset function
  • Programmable Frequency Divider
  • Time-Base function
  • All instructions executed in one or two instruction cycles
  • Table read instructions
  • 63 powerful instructions
  • Up to 6-level subroutine nesting
  • Bit manipulation instruction
  • Wide range of available package types

Touch Key Features

  • Single Line Communication Serial Interface
  • Four or Eight Touch Key Inputs
  • Only requires one external reference capacitor
  • Auto-calibration
  • Reliable Touch Detections
  • High Power Supply Rejection

Technical Document

Other Information