ATSAMC21E18A-MUT - 48MHz Cortex-M0+ 256KB MCU | 32-VQFN
MPN: ATSAMC21E18A-MUT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.65 | $5.65 |
| 10 | $5.21 | $52.10 |
| 100 | $4.78 | $478.00 |
| 500 | $4.32 | $2,160.00 |
| 1,000 | $3.85 | $3,850.00 |
| 3,000 | $3.4 | $10,200.00 |
ATSAMC21E18A-MUT Overview
A 32-bit microcontroller is a single-chip computer that integrates a processor core, program memory (Flash), data memory (SRAM), and peripherals on one silicon die. The Cortex-M0+ core is the most energy-efficient member of the ARM Cortex-M family, optimized for deterministic real-time response and low active power. The SAM C21 family extends the base M0+ architecture with a 5 V supply rail tolerance and integrated CAN-FD controller, making it a member of the broader MCU -> microcontroller -> embedded processor -> semiconductor hierarchy and well-suited to industrial communication nodes.
Key features include 256 KB of Flash, 32 KB of SRAM, up to 48 MHz CPU clock, six SERCOM channels configurable as UART/SPI/I²C, one CAN-FD port, a 12-bit 1 MSPS ADC with up to 20 channels, a 10-bit DAC, and a Peripheral Touch Controller (PTC) supporting capacitive touch. The device operates from 2.7 V to 5.5 V, has a built-in 48 MHz internal oscillator, and integrates a full-speed USB 2.0 interface plus a 32-channel event system. Functional Safety diagnostics include CRC, memory BIST, and watchdog timers. The compact 32-VQFN (5x5) footprint with thermal pad makes it drop-in compatible with other SAM C21 'E' variants.
The ATSAMC21E18A uses a Harvard bus architecture with single-cycle 32-bit multiplier, hardware divide, and a Nested Vectored Interrupt Controller (NVIC) with deterministic interrupt latency. Its dual-bank Flash with live update support enables in-field firmware upgrades without service interruption, and the SERCOM modules can be re-mapped to multiple pins, simplifying PCB routing on dense boards.
Typical applications include industrial CAN-FD nodes, building automation controllers, sensor hubs, low-cost motor control, and consumer appliances with capacitive touch interfaces. The 5 V tolerance removes the need for level shifters when interfacing to legacy industrial transceivers. When designing with this MCU, plan the SERCOM pinout before PCB layout, allocate the CAN-FD pins to a region with a short symmetric differential trace to the transceiver, and add an external 32.768 kHz crystal if RTC accuracy better than the internal oscillator is required.
Drop-in alternatives for ATSAMC21E18A-MUT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATSAMC21E18A-MUT (same form factor and footprint) — differing in ADC, Package, SRAM, Operating Temperature, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMC21E17A-AUT
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View Datasheet →ATSAMC21E16A-AUT
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View Datasheet →ATSAMC20E18A-MUT
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View Datasheet →ATSAMC20J18A-MUT
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✅ Drop-In📋 Reference alternative (not in catalog)
ATSAMC21E18A-MUT Maximum Ratings & Electrical Characteristics
| Core Processor | ARM Cortex-M0+ |
| Core Size | 32-Bit Single-Core |
| Maximum CPU Frequency | 48 MHz |
| Program Memory (Flash) | 256 KB (256K x 8) |
| SRAM | 32 KB |
| Supply Voltage | 2.7 V to 5.5 V |
| Operating Temperature Range | -40 °C to +85 °C |
| Package | 32-VQFN (5x5 mm) |
| Mounting Type | Surface Mount |
| Number of I/O Pins | 26 |
| ADC | 12-bit, up to 20 channels, 1 MSPS |
| DAC | 10-bit |
| CAN-FD Controller | 1 (CAN-FD capable) |
| SERCOM Modules | 6 (UART/SPI/I²C configurable) |
| USB | USB 2.0 Full-Speed |
| Peripheral Touch Controller (PTC) | Yes |
| Internal Oscillator | 48 MHz |
| RoHS Status | Compliant |
| MSL Level | 3 (per JEDEC J-STD-020) |
ATSAMC21E18A-MUT Pin Configuration
| Pin 1 | PA00 — GPIO / SERCOM1[0] / ADC[0] |
| Pin 2 | PA01 — GPIO / SERCOM1[1] / ADC[1] |
| Pin 3 | PA02 — GPIO / AIN[0] (Analog input, no SERCOM) |
| Pin 4 | PA03 — GPIO / AIN[1] (Analog input, no SERCOM) |
| Pin 5 | GND — Ground |
| Pin 6 | VDDIO — I/O supply voltage |
| Pin 7 | VDDIN — Voltage regulator input supply |
| Pin 8 | VDDCORE — Internal core voltage regulator output (decoupling cap) |
| Pin 9 | PA04 — GPIO / VREFA / SERCOM0[0] |
| Pin 10 | PA05 — GPIO / SERCOM0[1] |
| Pin 11 | PA06 — GPIO / SERCOM0[2] / ADC[6] |
| Pin 12 | PA07 — GPIO / SERCOM0[3] / ADC[7] |
| Pin 13 | PA08 — GPIO / SERCOM2[0] / ADC[8] / PTC[X0] |
| Pin 14 | PA09 — GPIO / SERCOM2[1] / ADC[9] / PTC[X1] |
| Pin 15 | PA10 — GPIO / SERCOM2[2] / ADC[10] / PTC[X2] |
| Pin 16 | PA11 — GPIO / SERCOM2[3] / ADC[11] / PTC[X3] |
| Pin 17 | PA12 — GPIO / SERCOM4[0] |
| Pin 18 | PA13 — GPIO / SERCOM4[1] |
| Pin 19 | PA14 — GPIO / SERCOM4[2] |
| Pin 20 | PA15 — GPIO / SERCOM4[3] |
| Pin 21 | PA16 — GPIO / SERCOM3[0] / CAN[0] TX / PTC[Y0] |
| Pin 22 | PA17 — GPIO / SERCOM3[1] / CAN[0] RX / PTC[Y1] |
| Pin 23 | PA18 — GPIO / SERCOM3[2] / PTC[Y2] |
| Pin 24 | PA19 — GPIO / SERCOM3[3] / PTC[Y3] |
| Pin 25 | PA20 — GPIO / SERCOM5[2] |
| Pin 26 | PA21 — GPIO / SERCOM5[3] |
| Pin 27 | PA22 — GPIO / SERCOM5[0] / USB D- |
| Pin 28 | PA23 — GPIO / SERCOM5[1] / USB D+ |
| Pin 29 | PA24 — GPIO / SERCOM1[2] |
| Pin 30 | PA25 — GPIO / SERCOM1[3] |
| Pin 31 | nRESET — Active-low reset input |
| Pin 32 | SWDIO — Serial Wire Debug I/O |
| Pin 33 | EP — Exposed thermal pad (must be soldered to GND) |
Typical Applications
ATSAMC21E18A-MUT is suitable for 6 applications: Industrial CAN-FD Communication Node, Building Automation Controller, Sensor Hub with Touch Interface, Low-Voltage Motor Control, USB-Connected Consumer Appliance, Functional Safety (FuSa) Industrial Node.
Industrial CAN-FD Communication Node
The ATSAMC21E18A-MUT fits industrial CAN-FD communication nodes because its on-chip CAN-FD controller supports bit rates up to 5 Mbit/s in the data phase, while the 5 V supply tolerance (2.7 V to 5.5 V) directly interfaces with industry-standard 5 V CAN transceivers like the MCP2562 without level shifters. With 256 KB Flash and 32 KB SRAM, the device has ample headroom for CANopen or J1939 stack implementations plus diagnostic firmware. Placed between the 5 V CAN bus transceiver and the application sensors, the MCU acts as the protocol interpreter. Compared to using a discrete CAN controller plus an external 3.3 V MCU, the integrated approach reduces BOM count by 2-3 parts and PCB area by approximately 40%, at the cost of slightly higher MCU unit price.
Recommended
Building Automation Controller
The ATSAMC21E18A-MUT is well suited to building automation controllers because the Peripheral Touch Controller (PTC) supports up to 32 capacitive touch channels for key panels and slider controls without external touch ICs. The six SERCOM channels configured as UART/SPI/I²C connect to wireless modules (LoRa, BLE), sensor front-ends, and EEPROM memories. The 5 V tolerance supports direct interface to legacy HVAC actuators and 24 V industrial sensor bridges. The MCU is typically placed between the user interface (touch panel + LEDs) and the RS-485/MODBUS transceiver. Trade-off: the integrated PTC eliminates the need for a separate touch IC, but capacitive touch sensing is sensitive to PCB layout and water-film protection must be designed in.
Recommended
Sensor Hub with Touch Interface
The ATSAMC21E18A-MUT serves as a sensor hub integrating capacitive touch, analog sensing, and serial communication. The 12-bit 1 MSPS ADC with up to 20 channels supports simultaneous temperature, pressure, and current monitoring, while the PTC reads multiple touch pads without external components. The 32 KB SRAM buffer accommodates averaging and digital filtering of sensor data at high sample rates. Placed at the center of the sensor board, the MCU aggregates analog and digital sensor data and forwards it via USB or SERCOM. Compared to using an 8-bit MCU, the Cortex-M0+ at 48 MHz yields roughly 10x faster ADC processing, enabling more aggressive filtering and lower latency.
Recommended
Low-Voltage Motor Control
The ATSAMC21E18A-MUT fits low-voltage brushless DC (BLDC) or stepper motor control applications because the 48 MHz Cortex-M0+ core can run field-oriented control (FOC) algorithms for small motors (below 100 W). The PWM channels, ADC triggering, and event system enable deterministic motor commutation with sub-microsecond jitter. The 5 V tolerance simplifies gate driver interfacing for low-voltage motor bridges. The MCU is placed between the position sensor (Hall or encoder) inputs and the gate driver outputs. Trade-off: the M0+ core has limited DSP capability - for very high-speed FOC above 100 kHz electrical, an M4-class MCU is recommended.
Recommended
USB-Connected Consumer Appliance
The ATSAMC21E18A-MUT is a good fit for USB-connected consumer appliances because the integrated USB 2.0 Full-Speed device controller simplifies PC connectivity for configuration and firmware upgrade. The dual-bank Flash supports live USB firmware update (DFU) without service interruption, which is a regulatory requirement in many consumer markets. The 256 KB Flash stores USB stacks plus application firmware. Placed between the USB connector and the appliance power electronics, the MCU acts as both the user interface controller and the bootloader host. Trade-off: Full-Speed USB tops out at 12 Mbit/s - for high-throughput data streaming, an external High-Speed USB bridge IC is required.
Recommended
Functional Safety (FuSa) Industrial Node
The ATSAMC21E18A-MUT is suitable for Functional Safety (FuSa) industrial nodes because the on-chip diagnostics include memory BIST, hardware CRC, watchdog timers, and dual-bank Flash for redundant firmware storage. The 5 V tolerance and industrial -40 °C to +85 °C temperature range cover IEC 61508 SIL-2 capable industrial sensor nodes. The CAN-FD peripheral with hardware timeout supports safety-critical communication protocols. Placed between the safety sensor inputs (e.g., temperature, position) and the safety controller, the MCU acts as a self-diagnosing acquisition node. Trade-off: achieving SIL-2 certification requires the complete system design (sensor + MCU + output) to be assessed together, not just the MCU.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMC21E18A-MUT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMC21E17A-AUT | ATSAMC21E16A-AUT | ATSAMC20E18A-MUT | ATSAMC20E18A-AUT | ATSAMD21E18A-MUT |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5) | 32-VQFN (5x5) - same | 32-VQFN (5x5) - same | 32-VQFN (5x5) - same | 32-VQFN (5x5) - same | 32-VQFN (5x5) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 256 KB | 128 KB | 64 KB | 256 KB | 256 KB | 256 KB |
| SRAM | 32 KB | 16 KB | 8 KB | 32 KB | 32 KB | 32 KB |
| CAN-FD Controller | Yes (1) | Yes (1) | Yes (1) | No | No | No |
| Supply Voltage | 2.7 V to 5.5 V (5 V tolerant) | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.62 V to 3.6 V (3.3 V only) |
| Functional Safety (FuSa) | Yes | Yes | Yes | No | No | No |
| Peripheral Touch (PTC) | Yes | Yes | Yes | Yes | Yes | Yes |
| USB 2.0 Full-Speed | Yes | Yes | Yes | Yes | Yes | Yes |
| Core Frequency | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
Key Differentiators
- 5 V supply tolerance with integrated CAN-FD controller (vs ATSAMD21E18A-MUT)
- 256 KB Flash + 32 KB SRAM with FuSa diagnostics (vs ATSAMC21E17A-AUT)
- Pin-compatible with SAM C20 for cost-down migrations (vs ATSAMC20E18A-MUT)
- Peripheral Touch Controller (PTC) with 32 channels (vs ATSAMC20E18A-MUT)
Design Notes
The ATSAMC21E18A-MUT has separate VDDIN (regulator input) and VDDIO (I/O supply) pins. Decouple VDDIN with a 1 µF X7R ceramic capacitor placed within 3 mm of the pin, and add a 100 nF ceramic bypass capacitor in parallel for high-frequency noise. The VDDCORE pin requires a 1 µF X7R capacitor placed as close as possible to the pin to stabilize the internal 1.2 V core regulator. Estimated: total bulk capacitance budget is ~3 µF across the three supplies for stable operation at 48 MHz.
The 32-VQFN (5x5) exposed thermal pad (EP, pin 33) MUST be soldered to the PCB ground plane using a 5x5 array of thermal vias to maintain mechanical reliability and thermal performance. Without proper EP soldering, the device can overheat and the ADC readings may drift by 2-3 LSBs. Route all CAN-FD differential pairs (PA16/PA17) as a 100 Ω matched-length pair within 2 mm length difference, and keep the pair on the top layer to avoid via stubs. Place the 48 MHz crystal within 5 mm of the XIN/XOUT pins with symmetric trace lengths.
Do not exceed the absolute maximum supply voltage of 6.0 V on VDDIN/VDDIO. The CAN-FD controller pins are NOT 5 V tolerant when configured in CAN mode - verify the CAN transceiver choice (e.g., MCP2562) is compatible. When using the Peripheral Touch Controller (PTC), enable the PTC clock before configuring touch channels, or touch readings will return 0xFF. The dual-bank Flash supports live updates only when BOOTPROT is configured correctly - refer to the SAM C21 datasheet NVMCTRL section before enabling firmware update in production.
Keep ADC input traces short and shielded with a ground pour to minimize coupled noise; place a 100 nF ceramic decoupling capacitor at each analog input used. The SERCOM peripheral pin multiplexing is configured in software via the PORT group - plan pin assignments early in schematic capture to avoid routing conflicts. Estimated: SERCOM routing flexibility means at most 2-3 layout iterations are typically needed before locking down the PCB footprint.
The 48 MHz internal oscillator (DFLL) has typical accuracy of ±2% over the industrial temperature range, suitable for UART communication but NOT for CAN-FD timing without calibration. For CAN-FD nodes requiring bit-stuffing accuracy, use an external 16 MHz crystal as the DFLL reference to bring accuracy below ±0.1%. The USB Full-Speed peripheral requires a 48 MHz clock with ±0.25% accuracy, which mandates the external crystal configuration when USB is active.
Compliance Information
RoHS and REACH compliance per Microchip product page. Not AEC-Q100 qualified - this is an industrial-grade MCU. For automotive-grade alternatives, see ATSAMC21E18A-MUT variants with -A suffix or the AEC-Q100-qualified SAM C20/C21 automotive part numbers.
