ATMEGA808-MU - 8KB AVR MCU 20MHz VQFN-32 | Microchip
MPN: ATMEGA808-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.15 | $1.15 |
| 10 | $1.03 | $10.30 |
| 100 | $0.89 | $89.00 |
| 500 | $0.78 | $390.00 |
| 1,000 | $0.68 | $680.00 |
ATMEGA808-MU Overview
An 8-bit microcontroller (MCU) is an integrated circuit that integrates a processor core, program memory, data memory, and peripherals on a single chip, executing one instruction over an 8-bit data bus. Within the embedded-system hierarchy, the MCU sits at the device level below system-on-chip and application processors, and the megaAVR 0-series is Microchip's modernized AVR generation built on the latest Core Independent Peripherals philosophy, succeeding classic megaAVR parts such as the ATmega328P family while maintaining the AVR instruction-set heritage.
Key differentiating specifications include the wide 1.8V to 5.5V operating voltage range, which allows direct operation from single-cell Li-ion-adjacent 3.3V and 5V industrial rails; the 20 MHz maximum CPU clock with single-cycle hardware multiplier for efficient math; and Functional Safety (FuSa) documentation support, easing compliance work in safety-oriented designs. Connectivity covers I2C, SPI, and USART serial interfaces with 27 general-purpose I/O lines on the 32-pin variant.
Technically, the megaAVR 0-series AVR core features a modified Harvard architecture with a two-stage pipeline, single-cycle instruction execution for most instructions, and peripheral modules such as event system routing that let timers, ADCs, and communication blocks interact without CPU intervention, reducing interrupt latency and deterministic-jitter in real-time loops. Flash-based program memory supports in-system self-programming for bootloaders.
Typical applications include industrial control and automation nodes, consumer appliances and HVAC control boards, and motor control or LED lighting systems where a 5V-tolerant 8-bit MCU with rich timers is preferred over 32-bit parts for cost and simplicity. The FuSa support also suits functional-safety assessments in industrial equipment.
A key design consideration: supply decoupling and the exposed pad should be soldered to ground for thermal and EMC performance, and the 1.8-5.5V range means BOD thresholds must be programmed to match the rail.
This page synthesizes distributor pricing, drop-in alternatives within the megaAVR 0-series, and practical design guidance not found in the manufacturer datasheet, with pricing as of 2026-09-18.
Drop-in alternatives for ATMEGA808-MU β 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 ATMEGA808-MU (same form factor and footprint) β differing in Core Processor, Package, EEPROM, Flash Memory Size, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA809-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1608-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA3208-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.24 / Unit
View Datasheet βATMEGA4808-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.22 / Unit
View Datasheet βATMEGA808-MFR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA808-MU Maximum Ratings & Electrical Characteristics
| Core Processor | AVR (megaAVR 0-series) |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 8 KB (8K x 8) |
| SRAM | 1 KB |
| EEPROM | 256 Byte |
| Operating Voltage Range | 1.8 V to 5.5 V |
| Connectivity | I2C, SPI, USART |
| Number of I/O | 27 |
| Hardware Multiplier | Yes |
| Functional Safety Support | FuSa (Functional Safety) documentation available |
| Operating Temperature | -40C to +85C |
| Package | 32-VQFN (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Program Memory Type | FLASH |
| RoHS Status | Compliant (per JLCPCB listing) |
ATMEGA808-MU 32-vqfn (5x5 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATMEGA808-MU (32-vqfn (5x5 mm) with exposed pad package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA808-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA808-MU is suitable for 6 applications: Industrial Control and Automation Nodes, Home Appliances and HVAC Control, Motor Control and Fan Drivers, LED Lighting and Dimming Systems, IoT Sensor Nodes and Gateways (sub-GHz front ends), Functional-Safety-Oriented Subsystems.
Industrial Control and Automation Nodes
The ATMEGA808-MU fits industrial control nodes because its 20 MHz AVR core with hardware multiplier handles control-loop math at low cost, while the 1.8-5.5V supply range accepts regulated 5V industrial rails directly without level shifting to 3.3V logic. With 27 GPIO and I2C, SPI, and USART interfaces, it comfortably drives relays, reads sensors, and reports to a PLC or SCADA layer. Core Independent Peripherals and the event system keep timer-driven sequencing deterministic even under heavy communication load, and the -40C to +85C rating covers unconditioned cabinets. Microchip's FuSa documentation support further eases assessment in safety-relevant automation equipment, making this MCU a pragmatic 8-bit choice where a 32-bit part would add cost without adding value.
Recommended
Home Appliances and HVAC Control
Appliance and HVAC controller boards benefit from the ATMEGA808-MU's combination of wide 1.8-5.5V operation, robust -40C to +85C temperature rating, and abundant GPIO for keypad scanning, LED indication, relay and triac driving. The 20 MHz core with hardware multiplier executes PID temperature-control loops with headroom at 8 KB Flash, and 256 bytes of EEPROM retains user settings and fault counters across power cycles. USART and I2C links integrate display drivers, NTC-front-end ADCs, or external EEPROM. Because Core Independent Peripherals time PWM outputs autonomously, heater or fan PWM continues correctly even while the CPU is busy with communication - a frequent failure mode on cheaper 8-bit parts - improving reliability in duty-cycled appliance environments.
Recommended
Motor Control and Fan Drivers
For small BLDC, brushed-DC, and fan motor control, the ATMEGA808-MU offers multiple hardware timer PWM outputs routed through the event system, letting the CPU offload commutation and duty-cycle generation entirely. The 20 MHz clock resolution gives fine PWM granularity for quiet fan operation, while the hardware multiplier accelerates speed-ramp and PI-controller calculations within the 8 KB Flash budget. The wide 1.8-5.5V input range allows the same firmware across 3.3V logic-domain designs and 5V gate-drive designs. Tachometer pulses can be captured by peripheral input capture without CPU jitter, and the VQFN-32 (5x5) footprint keeps the controller compact on dense driver boards typical of modern appliance and industrial blower assemblies.
Recommended
LED Lighting and Dimming Systems
LED luminaires and dimming controllers use the ATMEGA808-MU for its deterministic, peripheral-driven PWM: hardware timers generate flicker-free dimming curves while the CPU manages DALI-style USART frames, I2C ambient-light sensors, or push-dim inputs. The 5V tolerance and wide 1.8-5.5V range simplify integration with offline-supply secondary rails, and -40C to +85C operation suits enclosed, thermally stressful luminaires. The 8 KB Flash accommodates dimming curves, fade algorithms, and a USART bootloader for field updates, while 256 bytes of EEPROM stores last-set brightness across outages. Using the event system, analog-dimmer input sampling and PWM output updates stay synchronized, avoiding the beat-frequency artifacts common when dimming loops run in software on busy 8-bit MCUs.
Recommended
IoT Sensor Nodes and Gateways (sub-GHz front ends)
In battery- and line-powered IoT sensor nodes, the ATMEGA808-MU serves as the main controller interfacing sensors over I2C/SPI and a sub-GHz or proprietary radio module over USART. The AVR 0-series sleep architecture plus a 20 MHz core that finishes tasks quickly supports duty-cycled, energy-aware firmware, and 256 bytes of EEPROM caches calibration and node identity. Its 5V tolerance bridges 3.3V radio modules and legacy 5V field sensors in the same design. Core Independent Peripherals can acquire and pre-filter sensor data while the CPU sleeps between radio transmissions, extending battery life. Although the part has no integrated radio, pairing it with a dedicated RF transceiver module yields a low-BOM-cost node with well-understood 8-bit firmware, supported by the open MegaCoreX Arduino ecosystem for rapid prototyping.
Recommended
Functional-Safety-Oriented Subsystems
The megaAVR 0-series, including the ATMEGA808-MU, is listed by DigiKey as a Functional Safety (FuSa) microcontroller line, meaning Microchip provides safety documentation packages that support assessments under industrial functional-safety frameworks. In practice this suits safety-adjacent (non-silicon-certified) subsystems: watchdog supervision, sensor-plausibility checks, and two-channel shutdown logic in machines where the MCU contributes to a safety function assessed at the system level. The deterministic AVR core, hardware CRC-capable Flash self-programming for bootloaders, and Core Independent Peripherals that keep timing behavior predictable under CPU load all simplify the safety analysis. Designers should request the specific FuSa safety manual for ATmega808 from Microchip and confirm the target standard coverage before locking the architecture.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA808-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA809-MU | ATMEGA1608-MU | ATMEGA3208-MU | ATMEGA4808-MUR | ATMEGA808-MFR |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | VQFN-32 rotated footprint - NOT footprint-identical |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 8 KB | 8 KB | 16 KB | 32 KB | 48 KB | 8 KB |
| SRAM | 1 KB | 1 KB | 2 KB | 4 KB | 6 KB | 1 KB |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Drop-in Compatibility | Reference part | Pin-to-pin, no firmware change | Pin-to-pin, no firmware change | Pin-to-pin, no firmware change | Pin-to-pin, no firmware change | Electrical drop-in; footprint rotated - check PCB |
Key Differentiators
- Lowest-cost entry of the pin-compatible megaAVR 0-series 32-pin family (vs ATMEGA4808-MUR)
- Functional Safety (FuSa) documentation support (vs ATmega328P)
- Trade-off: minimal 1 KB SRAM (vs ATMEGA1608-MU)
Design Notes
The ATMEGA808-MU's 32-VQFN (5x5) has an exposed pad that must be soldered to the ground plane - do not treat it as a no-connect. Use a 3x3 or larger thermal via array under the pad for reliable reflow and best EMC performance. Place a 100 nF ceramic decoupling capacitor within 2 mm of each VDD pin pair plus one bulk 4.7-10 uF capacitor near the supply entry. Verify the land pattern against Microchip's mechanical drawing for the MU (standard) footprint, since the MFR variant uses a rotated pad arrangement and is not interchangeable on the same PCB.
Although rated 1.8-5.5V, set the Brown-Out Detector (BOD) fuse/EEPROM configuration to match your actual rail (e.g., 2.7V threshold for 5V systems) so Flash writes and SRAM state are protected during brown-outs. Flash self-programming has minimum voltage requirements at the low end of the range - check the datasheet operating-profile tables before enabling a bootloader on 1.8V supplies. Estimated: at 20 MHz and 5V the AVR 0-series active current is on the order of 5-6 mA (per family typical curves), so battery designs should exploit the sleep modes and event-driven peripheral operation rather than polling loops.
Two frequent mistakes with this part: (1) assuming any ATMEGA808 suffix is footprint-identical - the MU and MFR packages differ in pin-1 orientation, so order the MU for existing ATMEGA808-MU layouts; (2) assuming larger-flash family parts need code changes - ATMEGA1608/3208/4808 run ATmega808 firmware unchanged, making them the correct shortage substitution. When migrating from classic AVRs like ATmega328P, remember the 0-series has a different peripheral register map and requires MegaCoreX or MPLAB XC8 0-series device packs - classic AVR code will not compile unchanged.
Compliance Information
RoHS compliance per JLCPCB product listing (C1340539). Not an automotive-qualified suffix; DigiKey lists Functional Safety (FuSa) documentation support for the megaAVR 0-series. REACH/halogen-free/conflict-minerals status not stated in provided data.
