BS45R2141

General Information

The device is an OTP type 8-bit high performance RISC architecture microcontroller, designed for 3.7V lithium touch personal care products (electric toothbrushes, shavers, etc.) and 3.7V lithium portable touch electronic products.

For memory features, the device is supplied with One-Time Programmable, OTP memory. Other memory includes an area of RAM Data Memory.

Analog features include a multi-channel 12-bit A/D Converter. Multiple Timer Modules for time measurement, input capture, compare match output or PWM output or single pulse output function. Communication with the outside world is catered for by including fully integrated I²C interface function, the popular interface which provides designers with a means of easy communication with external peripheral hardware. Protective features such as an internal Watchdog Timer and Low Voltage Reset coupled with excellent noise immunity and ESD protection ensure that reliable operation is maintained in hostile electrical environments.

A full choice of internal high and low speed oscillators are provided and the two fully integrated system oscillators require no external components for their implementation. The ability to operate and switch dynamically between a range of operating modes using different clock sources gives users the ability to optimize microcontroller operation and minimize power consumption. The inclusion of flexible I/O programming features, Time-Base funcitons, a CRC and Sink Current Generator along with many other features ensure that the device will find excellent use.

The device includes 3 touch keys which can detect human body contact using external touch pads. The high level of device integration enable applications to be implemented with a minimum number of external components.

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, excellent resistance to voltage fluctuation and other features, this touch key device provides a simple and effective means of implementing touch key operation in a wide variety of applications.

The device includes the functions of input over/under voltage protection, linear charger, charger status indication, reference voltage output, etc. It supports a maximum input rating of 20V to overcome unexpected high voltage from the USB input. The linear charger provides an up to 1A charging current for the Li-ion battery. The reference voltage function is used by the MCU for measuring battery voltage and current. The device uses a two-line communication interface to select different function, such as to control the linear charger and reference voltage function, or to read the charging status and control the STDBY signal and CHRG pin by using the FN signal.

The device will find excellent use in a huge range of 3.7V lithium touch personal care products (electric toothbrushes, shavers, etc.) and 3.7V lithium portable touch electronic products to name but a few.