SAM R34 Arm® Cortex® -M0+ MCUs with Inte

By Microchip Technology 180

SAM R34 Arm® Cortex® -M0+ MCUs with Inte

Microchip's SAM R34 and R35 product families are ultra-low power microcontrollers combined with a UHF transceiver communication interface. They use a 32-bit Arm Cortex -M0+ processor and offer up to 256 KB of flash and 40 KB of SRAM, including an area of battery backed-up SRAM. The UHF transceiver supports LoRa and FSK modulation. LoRa technology is a spread spectrum protocol optimized for low data-rate, ultra-long-range signaling. It is ideal for battery-powered remote sensors and controls. The SAM R34 includes an integrated microcontroller with USB and the UHF transceiver, making it suitable for USB dongle applications or for software updates via USB. The SAM R35 offers the same microcontroller functions along with the UHF transceiver, without the USB interface.

The UHF transceiver supports LoRa and FSK modulation schemes. The LoRa technology is optimized for long-range communication with minimal line-power demand. The transceiver can work from frequencies of 137 MHz to 1020 MHz. Maximum transmit power is +20 dBm without external amplification. Operational frequency bands and power limits are defined by local regulations and the LoRa alliance. LoRa network stack regional options ensure compliance. FSK modulation is also supported for applications, including IEEE 802.15.4g, Wi-SUN, and legacy proprietary networks.

MCU Features
  • Processor:
    • Arm Cortex -M0+ CPU running at up to 48 MHz (2.46 CoreMark®/MHz)
    • Single-cycle hardware multiplier
    • Micro trace buffer (MTB)
  • Memory:
    • In-system self-programmable flash memory, with options for sizes 256 KB, 128 KB, or 64 KB
    • Static random-access memory (SRAM) with options for sizes 32 KB, 16 KB, or 8KB
    • 8 KB low-power RAM with battery backup retention (with 4 KB option)
  • Operating voltage: 1.8 V to 3.6 V
  • System:
    • Power-on reset (POR) and brown-out reset
    • Internal and external clock options with 48 MHz digital frequency locked loop (DFLL48M) and 48 MHz to 96 MHz fractional digital phase locked loop (FDPLL96M)
    • External interrupt controller (EIC)
    • Up to 15 external interrupts
    • One non-maskable interrupt
    • Two-pin serial wire debug (SWD) programming, test, and debugging interfaces
RF/Analog Features
  • Integrated LoRa technology transceiver:
    • Tri-band coverage
      • 137 MHz to 175 MHz
      • 410 MHz to 525 MHz
      • 862 MHz to 1020 MHz
    • +20 dBm (100 mW) max power (VDDANA > 2.4 VDC)
    • +17 dBm (50 mW) max power (regulated PA)
    • +13 dBm (20 mW) high-efficiency PA
  • High sensitivity:
    • Down to -136 dBm (LoRaWAN™ protocol compliant modes)
    • Down to -148 dBm (proprietary narrowband modes)
  • Up to 168 dB maximum link budget
  • Robust front-end: IIp3 = -11 dBm
  • Excellent blocking immunity
  • Low RX current of 17 mA (typical)
  • Fully integrated synthesizer with a resolution of 61 Hz
  • LoRa technology, (G)FSK, (G)MSK and OOK modulation
  • Preamble detection
  • 127 dB dynamic range RSSI
  • Automatic RF sense and CAD with ultra-fast automatic frequency control (AFC) packet engine up to 256 B with cyclic redundancy check (CRC)