Atmel : New 5V, 32-bit MCUs SMART SAM C20 & SMART SAM C21 offer touch-sensing and flexible choice of communications options

The Atmel® | SMART SAM C20 and SAM C21 are families of 5V microcontrollers based on the low-power ARM® Cortex®-M0+ core which offer an unusually broad range of peripheral capabilities for use in industrial, home-appliance and control applications.

The SAM C2x MCUs operate from a wide 2.7V to 5.5V operating voltage, which provides for a good signal-tonoise ratio, and makes the devices robust against the dangers of noise, EMI, ESD and latch-up.

All the SAM C2x devices offer a QTouch® peripheral touch controller, giving built-in hardware support for buttons, sliders, wheels and proximity sensing. The QTouch controller supports both mutual- and self-capacitive touch-sensing without the need for external components. It provides superb sensitivity and noise tolerance, and supports self-calibration, which makes user tuning unnecessary.

The MCUs give designers a flexible choice of peripherals: an innovative serial communication module (SERCOM) is fully softwareconfigurable to handle I2C, USART/UART, SPI, RS-485 and LIN communications. With four (SAM C20) or six (SAM C21) SERCOM modules on a device, the peripheral mix may be precisely tailored to the needs of each application.

All these capabilities are available on both the SAM C20 and the SAM C21. In addition, the SAM C21 offers features including two modules supporting CAN 2.0A/B and CAN-FD 1.0, an RS-485 interface, DAC, and 16-bit sigma-delta ADC. The SAM C20 series features a 6-channel DMA controller supporting both memory and peripheral data transfers, while the SAM C21 features a 12-channel DMA controller.

Flash memory densities range from 32kbytes to 256kbytes, and the devices are available in packages with 32, 48 or 64 pins.


  • Operating frequency up to 48MHz
  • Up to five timer/counters and three timer/counters for control
  • 32-bit real-time clock and calendar
  • 14 PWM channels
  • Up to 18-channel, 12-bit ADC
  • Hardware divide and square-root module
  • Internal temperature sensor
  • Two analogue comparators
  • Configurable custom logic
  • Memory protection unit
  • Support for up to 256 touch channels


  • Home appliances
  • Industrial and home automation
  • Car access controls
  • Lighting control systems
  • Residential energy-usage display units


The Atmel SAM C21 Xplained Pro evaluation kit, which features an ATSAMC21J18A microcontroller, is supported by the Atmel Studio integrated development platform. It also includes an on-board embedded debugger and offers additional peripherals to extend the features of the board.

Orderable Part Number: ATSAMC21-XPRO