ATMEGA808-MU - 8KB AVR MCU 20MHz VQFN-32 | Microchip
MPN： ATMEGA808-MU ✓ 啟用中ATMEGA808-MU 概覽
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.
直接替換替代品，適用於 ATMEGA808-MU — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA808-MU （相同外形與佔位） — 差異在於 Core Processor, Package, Series, Connectivity, EEPROM.
ATMEGA809-MU
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA1608-MU
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ATMEGA3208-MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA4808-MUR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →ATMEGA808-MFR
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA808-MU 最大額定值與電氣特性
| Core Processor | AVR (megaAVR 0-series) |
| Core Size | 8-Bit |
| 最大時脈頻率 | 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 |
| 工作溫度 | -40C to +85C |
| 封裝 | 32-VQFN (5x5 mm) with exposed pad |
| 安裝類型 | Surface Mount |
| Packaging | Tray |
| Program Memory Type | FLASH |
| RoHS 狀態 | Compliant (per JLCPCB listing) |
ATMEGA808-MU 32-vqfn (5x5 mm) with exposed pad 腳位配置指南
ATMEGA808-MU（32-vqfn (5x5 mm) with exposed pad 封裝）的腳位配置。 此數位 IC 包含 GPIO、通訊介面（UART、SPI、I2C）與電源腳位。替代腳位功能與配置選項請參閱製造商資料表。對嵌入式系統設計與 PCB 佈局至關重要。
無詳細腳位定義資料： ATMEGA808-MU.
請參閱 資料表 以查看完整腳位配置。
典型應用
ATMEGA808-MU 適用於 6 應用s: 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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA808-MU — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- Lowest-cost entry of the pin-compatible megaAVR 0-series 32-pin family (對比ATMEGA4808-MUR)
- Functional Safety (FuSa) documentation support (對比ATmega328P)
- Trade-off: minimal 1 KB SRAM (對比ATMEGA1608-MU)
設計說明
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.
合規資訊
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.
