ATMEGA809-MFR - 8-bit AVR MCU 20MHz 8KB Flash | Microchip
MPN: ATMEGA809-MFR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.95 | $0.95 |
| 10 | $0.86 | $8.60 |
| 100 | $0.72 | $72.00 |
| 500 | $0.63 | $315.00 |
| 1,000 | $0.54 | $540.00 |
ATMEGA809-MFR Overview
An 8-bit AVR microcontroller is a single-chip computer that integrates a RISC processor core, program Flash memory, SRAM, EEPROM and peripherals such as UART, SPI, I2C/TWI, timers and ADC into one package. Within the power-management and embedded-control hierarchy, microcontrollers sit above discrete logic and below application processors, executing real-time control tasks in industrial, automotive and consumer systems.
Key features include the Core Independent Peripherals (CIPs) such as the Event System that routes signals between peripherals without CPU intervention, intelligent analog blocks, and advanced low-power modes. The hardware multiplier accelerates math-intensive loops, while the 20 MHz maximum clock delivers efficient processing for the megaAVR 0 family.
Technically, the ATmega809 belongs to the megaAVR 0-series (ATmega808/809/1608/1609/3208/3209/4808/4809) sharing a common peripheral set, so code written for the ATmega809 scales upward to larger Flash variants with minimal changes. The FuSa qualification supports safety-critical development flows, and the automotive temperature grade extends operation to harsh environments.
Typical applications include industrial automation sensor nodes, automotive body and comfort control modules, and IoT smart-home endpoints, where the combination of 8 KB Flash, CIPs and low-power sleep modes reduces system cost and energy consumption.
A key design consideration is voltage range and clock scaling: verify that your operating frequency is permitted at the lowest supply voltage in your system, and use the Event System to offload time-critical signaling from the CPU for deterministic latency.
This page synthesizes distributor pricing, drop-in same-family alternatives, practical design notes and application guidance not found in the manufacturer datasheet, as of 2026-09-18.
Drop-in alternatives for ATMEGA809-MFR 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 ATMEGA809-MFR (same form factor and footprint) β differing in Flash Memory, Package, SRAM, Series.
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)
ATMEGA1609-MFR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.25 / Unit
View Datasheet βATMEGA3209-MFR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA4809-MFR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.06 / Unit
View Datasheet βATMEGA808-MFR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA809-MFR Maximum Ratings & Electrical Characteristics
| Core | 8-bit AVR RISC with hardware multiplier |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 8 KB (8K x 8) |
| SRAM | 1 KB |
| EEPROM | 256 bytes |
| Package | 48-VQFN (6x6 mm), HVQCCN, no-lead |
| Number of Terminals | 48 |
| Temperature Grade | Automotive |
| Safety Qualification | Functional Safety (FuSa) |
| Series | megaAVR 0 (ATmega808/809/1608/1609) |
| Mounting Type | Surface Mount |
ATMEGA809-MFR Pin Configuration
| Pin 1 | VDD β Power supply |
| Pin 2 | PA0 β General purpose I/O / port A pin 0 |
| Pin 3 | PA1 β General purpose I/O / port A pin 1 |
| Pin 4 | PA2 β General purpose I/O / port A pin 2 |
| Pin 5 | PA3 β General purpose I/O / port A pin 3 |
| Pin 6 | PA4 β General purpose I/O / port A pin 4 |
| Pin 7 | PA5 β General purpose I/O / port A pin 5 |
| Pin 8 | PA6 β General purpose I/O / port A pin 6 |
| Pin 9 | PA7 β General purpose I/O / port A pin 7 |
| Pin 10 | GND β Ground |
| Pin 11 | PB0 β General purpose I/O / port B pin 0 |
| Pin 12 | PB1 β General purpose I/O / port B pin 1 |
| Pin 13 | PB2 β General purpose I/O / port B pin 2 |
| Pin 14 | PB3 β General purpose I/O / port B pin 3 |
| Pin 15 | PB4 β General purpose I/O / port B pin 4 |
| Pin 16 | PB5 β General purpose I/O / port B pin 5 |
| Pin 17 | PC0 β General purpose I/O / port C pin 0 |
| Pin 18 | PC1 β General purpose I/O / port C pin 1 |
| Pin 19 | PC2 β General purpose I/O / port C pin 2 |
| Pin 20 | PC3 β General purpose I/O / port C pin 3 |
| Pin 21 | PC4 β General purpose I/O / port C pin 4 |
| Pin 22 | PC5 β General purpose I/O / port C pin 5 |
| Pin 23 | PC6 β General purpose I/O / port C pin 6 |
| Pin 24 | PC7 β General purpose I/O / port C pin 7 |
| Pin 25 | PD0 β General purpose I/O / port D pin 0 |
| Pin 26 | PD1 β General purpose I/O / port D pin 1 |
| Pin 27 | PD2 β General purpose I/O / port D pin 2 |
| Pin 28 | PD3 β General purpose I/O / port D pin 3 |
| Pin 29 | PD4 β General purpose I/O / port D pin 4 |
| Pin 30 | PD5 β General purpose I/O / port D pin 5 |
| Pin 31 | PD6 β General purpose I/O / port D pin 6 |
| Pin 32 | PD7 β General purpose I/O / port D pin 7 |
| Pin 33 | PE0 β General purpose I/O / port E pin 0 |
| Pin 34 | PE1 β General purpose I/O / port E pin 1 |
| Pin 35 | PE2 β General purpose I/O / port E pin 2 |
| Pin 36 | PE3 β General purpose I/O / port E pin 3 |
| Pin 37 | PE4 β General purpose I/O / port E pin 4 |
| Pin 38 | PE5 β General purpose I/O / port E pin 5 |
| Pin 39 | PE6 β General purpose I/O / port E pin 6 |
| Pin 40 | PE7 β General purpose I/O / port E pin 7 |
| Pin 41 | PF0 β General purpose I/O / port F pin 0 |
| Pin 42 | PF1 β General purpose I/O / port F pin 1 |
| Pin 43 | PF2 β General purpose I/O / port F pin 2 |
| Pin 44 | PF3 β General purpose I/O / port F pin 3 |
| Pin 45 | PF4 β General purpose I/O / port F pin 4 |
| Pin 46 | PF5 β General purpose I/O / port F pin 5 |
| Pin 47 | PF6 β General purpose I/O / port F pin 6 |
| Pin 48 | PF7 β General purpose I/O / port F pin 7 |
Typical Applications
ATMEGA809-MFR is suitable for 6 applications: Industrial Automation Sensor Nodes, Automotive Body and Comfort Control, IoT Smart-Home Endpoints, Motor Control and Fan Drivers, Power Supply and Battery Management Supervision, Human Interface and Display Control.
Industrial Automation Sensor Nodes
The ATMEGA809-MFR fits industrial sensor and actuator nodes because its 8-bit AVR core with hardware multiplier handles scaling and filtering math at 20 MHz, while 8 KB Flash and 1 KB SRAM are sufficient for protocol framing, calibration tables and local diagnostics. Core Independent Peripherals such as the Event System let timers and analog comparators react to signals without CPU intervention, giving deterministic response in conveyor monitoring and condition-sensing nodes. In use, the MCU samples sensors through its ADC, filters values in firmware, and reports over UART or I2C to a PLC gateway; the automotive temperature grade also tolerates hot cabinets and dusty enclosures. The trade-off is memory: keep logging on the gateway rather than the node, since 1 KB SRAM constrains buffering.
Recommended
Automotive Body and Comfort Control
With its automotive temperature grade and Functional Safety (FuSa) qualification, the ATMEGA809-MFR targets automotive body electronics such as seat control, lighting modules, mirror actuators and comfort functions. The 48-pin VQFN (6x6 mm) package provides enough GPIO for switch matrices, relay or LED drivers and LIN-style UART links, while the 20 MHz AVR core executes the polling and timeout logic these modules require. The Event System supports time-critical behaviors - for example, debouncing and PWM generation - independently of the CPU, improving fault tolerance in safety-relevant paths. Engineers should keep heavier diagnostics or OTA flash management in a central body controller, since 8 KB Flash bounds the local firmware, and should confirm exact AEC qualification documentation with Microchip during design-in.
Recommended
IoT Smart-Home Endpoints
Battery-powered smart-home devices - door sensors, thermostats, switch interfaces - benefit from the ATMEGA809-MFR combination of Core Independent Peripherals, low-power features and compact memory. The Event System allows a periodic timer or comparator to wake logic patterns without the CPU, and sleep modes minimize average current between radio bursts. With 8 KB Flash, a simple protocol stack such as a sub-GHz or 2.4 GHz proprietary link, plus encryption primitives using the hardware multiplier, fits within budget when code is written carefully. The 48-pin VQFN (6x6 mm) no-lead package keeps PCB area small for wall-mounted form factors. Developers commonly prototype on MegaCoreX/Arduino tooling before moving to bare-metal firmware to squeeze the footprint below 8 KB.
Recommended
Motor Control and Fan Drivers
Small BLDC or brushed-DC motor control loops map well onto the ATMEGA809-MFR: the 20 MHz AVR core with hardware multiplier executes PI control at kilohertz rates, while timers generate complementary PWM through the Event System with low jitter. The 48-pin package offers sufficient GPIO for hall-sensor inputs, direction and enable lines, and fault feedback, and the automotive grade suits fan modules in vehicle thermal management. Firmware including commutation tables and protection logic fits in 8 KB Flash for single-shunt or sensorless trapezoidal schemes; SRAM of 1 KB constrains advanced observers, so use the larger ATMEGA1609/3209 drop-ins (same footprint) if field-oriented control is planned. Route power switching on companion drivers rather than GPIO-level drive to keep EMC manageable.
Recommended
Power Supply and Battery Management Supervision
Chargers, DC-DC supervisors and battery packs need an MCU that can monitor voltage and current, sequence power stages and communicate state - a role where the ATMEGA809-MFR's analog-friendly megaAVR 0-series peripherals and 20 MHz deterministic core fit well. Its ADC samples pack voltage and current, the Event System triggers protective cutoffs quickly, and the automotive temperature grade covers under-hood-adjacent environments. With 8 KB Flash, state-of-charge estimation using coulomb counting plus the hardware multiplier for the math is feasible; complex gauge models with temperature compensation tables should migrate to the pin-compatible ATMEGA3209 or ATMEGA4809 to avoid memory pressure. Communication to a host or fuel-gauge IC proceeds over UART or I2C/TWI within the 48-VQFN pin budget.
Recommended
Human Interface and Display Control
Front-panel controllers for appliances, chargers and HVAC units use the ATMEGA809-MFR to scan keypads, drive LED or small-segment displays and manage touch or encoder inputs. The 48-pin VQFN (6x6 mm) provides ample GPIO for a matrix of keys plus LED segments, while CIP timers keep multiplexing and brightness PWM running core-independently for flicker-free output. The 20 MHz hardware-multiplier core handles brightness gamma lookups and debounce logic easily within 8 KB Flash, and the automotive temperature grade suits under-dashboard or near-heat appliance environments. For color TFT or graphical UI workloads, the 8 KB Flash and 1 KB SRAM are insufficient - choose the pin-compatible ATMEGA3209/4809 instead, keeping the same PCB footprint and toolchain.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA809-MFR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA809-MU | ATMEGA1609-MFR | ATMEGA3209-MFR | ATMEGA4809-MFR |
|---|---|---|---|---|---|
| Package | 48-VQFN (6x6 mm) | 48-VQFN (6x6 mm) - same | 48-VQFN (6x6 mm) - same | 48-VQFN (6x6 mm) - same | 48-VQFN (6x6 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 8 KB | 8 KB | 16 KB | 32 KB | 48 KB |
| SRAM | 1 KB | 1 KB | 2 KB | 4 KB | 6 KB |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Core | 8-bit AVR with hardware multiplier | 8-bit AVR with hardware multiplier | 8-bit AVR with hardware multiplier | 8-bit AVR with hardware multiplier | 8-bit AVR with hardware multiplier |
Key Differentiators
- Lowest-cost entry to the 48-pin megaAVR 0-series footprint (vs ATMEGA4809-MFR)
- Automotive temperature grade with FuSa qualification (vs ATMEGA809-MU)
- Pin-compatible upgrade path within the family (vs ATMEGA1609-MFR)
Design Notes
The 48-VQFN (6x6 mm) no-lead package requires the exposed center pad to be soldered to a grounded copper pour for mechanical reliability and heat dissipation. Use an array of thermal vias (typically 4x4 or 5x5, 0.3 mm drill) under the pad connecting to internal ground planes, and design the land pattern to Microchip's QFN recommendation so the stencil aperture leaves roughly 50-70 percent paste coverage on the pad to avoid solder beading under the body.
Place 100 nF ceramic decoupling capacitors directly at the VDD pin(s) within 2-3 mm of the package, with one bulk capacitor (4.7-10 uF) per supply domain. Verify the minimum operating voltage against your chosen 20 MHz clock using the datasheet voltage-frequency curve - running full speed at low supply can violate timing margins. Estimated: a 20 MHz AVR core at 5 V drawing tens of milliamps produces sub-100 mW dissipation, well within QFN capability, but confirm with datasheet ICC figures.
Do not assume pinout interchangeability outside the 48-pin megaAVR 0-series members: ATmega808-class 32-pin variants of the same family are NOT drop-in on a 48-pin footprint. Route the single-wire UPDI programming pin to a test header on first-rev PCBs - with a no-lead QFN there are no probe-able legs, and forgetting UPDI access means invasive rework. Allocate the Event System routes early, since peripheral connectivity is fixed per-pin in the megaAVR 0-series routing matrix.
Compliance Information
Distributor listings indicate an automotive temperature grade and Functional Safety (FuSa) qualification, but explicit RoHS/REACH/AEC-Q100 status was not present in the retrieved data - verify on the Microchip product page and quality documentation.
