ATMEGA4809-MFR - 8-Bit AVR MCU 20MHz 48KB Flash | Microchip
MPN: ATMEGA4809-MFR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.46 | $14.60 |
| 100 | $1.31 | $131.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.06 | $1,060.00 |
ATMEGA4809-MFR Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, memory, and programmable peripherals on one die. The ATMEGA4809 belongs to the megaAVR 0-series family, which sits within Microchip's broader AVR product hierarchy alongside tinyAVR and AVR DA/DB series, and competes in the general-purpose 8-bit MCU market for embedded control systems.
Key features include the AVR RISC core with hardware multiplier, Microchip's Core Independent Peripherals (CIPs) that operate without CPU intervention, and low-power features including sleep modes and event routing. The 20 MHz maximum clock, 48 KB self-programmable Flash, and 6 KB SRAM make it a direct architectural successor to the popular ATmega328P used in Arduino boards, while offering significantly more memory and peripherals.
Technical depth: the megaAVR 0-series uses the latest Core Independent Peripherals such as TCA/TCB/TCD timers, USARTs with idle-line detection, a 10-bit ADC, analog comparators, and a configurable Custom Logic (CLC) block. The device supports 5V operation from 2.7 V to 5.5 V (per family supply range) and industrial temperature operation, and the -MFR variant is designated by Microchip for Functional Safety documentation support.
Typical applications include industrial control and automation nodes, Arduino Nano Every class designs, motor control and LED drivers via TCD/PWM peripherals, and safety-conscious embedded systems that benefit from the FuSa qualification flow.
Design consideration: the 40-pin ATmega4809 variants share the 48-pin die but expose fewer pads; pins PB[5:0] and PC[7:6] must be disabled or pulled up when porting designs across packages.
This page synthesizes distributor availability, drop-in packaging variants, pinout guidance, and design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA4809-MFR — 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 ATMEGA4809-MFR (same form factor and footprint) — differing in Flash Memory, Package, SRAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA4809-AFR
✅ Drop-In✓ In Stock
$1.36 / Unit
View Datasheet →ATMEGA4809-AFR-VAO
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA4809-MFR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC with hardware multiplier |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 48 KB (24K x 16) |
| SRAM | 6 KB |
| EEPROM | 256 bytes |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Package | 48-UQFN (6x6 mm) |
| Number of USARTs | 4 |
| ADC Resolution | 10-bit |
| Operating Temperature | -40C to +105C |
| Product Series | megaAVR 0-series (ATmega4809) |
| Functional Safety Support | Yes (FuSa variant) |
| Core Independent Peripherals | Yes (CIPs) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATMEGA4809-MFR 48-uqfn (6x6 mm) Pin Configuration Guide
Pin configuration for ATMEGA4809-MFR (48-uqfn (6x6 mm) 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 ATMEGA4809-MFR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA4809-MFR is suitable for 6 applications: Arduino-Compatible Embedded Development, Industrial Control and Automation Nodes, Motor Control and LED Driver Systems, Functional Safety Embedded Systems, IoT Sensor Nodes and Smart Home Devices, Legacy ATmega328P System Upgrades.
Arduino-Compatible Embedded Development
The ATmega4809 powers the Arduino Nano Every and Uno WiFi Rev 2, making the bare ATMEGA4809-MFR ideal for custom boards targeting the Arduino ecosystem. The MegaCoreX Arduino hardware package provides full core support for the ATmega4809 family, so existing Arduino sketches port with minimal changes. The four USARTs and 6 KB SRAM comfortably exceed the ATmega328P resources, allowing larger sketches and multiple serial links. Programming uses the UPDI interface on PA0, compatible with SNAP, PICkit 4, or pyupdi, so hobbyist-friendly tooling is preserved while gaining Core Independent Peripherals.
Recommended
Industrial Control and Automation Nodes
The ATMEGA4809-MFR's Core Independent Peripherals make it well suited for industrial sensor nodes and actuator controllers that run continuously without supervision. The TCA/TCB timers generate PWM and capture signals autonomously, while the event system routes peripheral signals without CPU loading, keeping response latency deterministic. With a 2.7 V to 5.5 V supply range and -40C to +105C operation, it tolerates noisy factory-floor power rails. The four USARTs connect RS-485 transceivers, HMIs, and gateways in multi-node networks. The 48 KB Flash accommodates protocol stacks such as Modbus with headroom for firmware updates.
Recommended
Motor Control and LED Driver Systems
The ATmega4809's TCD (Timer Type D) provides high-resolution asynchronous PWM ideal for motor control and LED dimming applications. Combined with the Custom Logic (CLC) blocks and analog comparators, fault protection and dead-time insertion can be implemented in hardware without CPU intervention, improving safety in brushed-DC and stepper motor drives. The 20 MHz core executes control loops with ample margin while the 10-bit ADC monitors current and temperature feedback channels. Designs migrating from ATmega328P motor drivers gain more timers, four USARTs, and higher SRAM for smoother multi-axis control.
Recommended
Functional Safety Embedded Systems
DigiKey classifies the ATMEGA4809-MFR as a Functional Safety (FuSa) MCU variant, and Microchip provides supporting documentation packages for safety-oriented development flows. In safety-relevant subsystems such as industrial interlocks and monitoring units, designers pair the 4809's hardware resources - comparators, WDT, and CIPs - with Microchip's FuSa documentation to build diagnostic coverage. The 48 KB Flash supports redundant code images and CRC self-test routines, while 6 KB SRAM holds diagnostic state machines. Always obtain the current safety manual from Microchip's ATMEGA4809 product page and verify it against the target standard revision.
Recommended
IoT Sensor Nodes and Smart Home Devices
For battery- and line-powered IoT nodes, the ATMEGA4809-MFR combines low-power sleep modes with enough 48 KB Flash to host sensor drivers plus a communication stack. Four USARTs interface with Wi-Fi/LoRa modules, and the 10-bit ADC reads analog sensors such as temperature, humidity, and light directly. The event system can wake and pre-process sensor readings via peripherals while the CPU sleeps, extending battery life versus polled designs. Running at 3.3 V reduces the maximum clock per the datasheet derating curve, so designers should size clock and baud rates accordingly for 3.3 V modules.
Recommended
Legacy ATmega328P System Upgrades
Designers outgrowing the ATmega328P's 32 KB Flash and 2 KB SRAM can migrate to the ATMEGA4809-MFR for a 50% Flash increase and 3x SRAM gain at the same 20 MHz speed. The megaAVR 0-series keeps the AVR instruction set familiarity, easing code migration, though it is not pin-compatible so a PCB respin with the 48-UQFN (6x6 mm) footprint is required. The added four USARTs, extra timers, and CLC logic blocks let one chip absorb tasks previously split across multiple ATmega328Ps. MegaCoreX maintains Arduino compatibility during the transition.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA4809-MFR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA4809-AFR | ATMEGA4809-AFR-VAO |
|---|---|---|---|
| Package | 48-UQFN (6x6 mm) | 48-UQFN (6x6 mm) - same | 48-UQFN (6x6 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Clock | 8-bit AVR, 20 MHz | 8-bit AVR, 20 MHz | 8-bit AVR, 20 MHz |
| Flash Memory | 48 KB | 48 KB | 48 KB |
| SRAM | 6 KB | 6 KB | 6 KB |
| EEPROM | 256 bytes | 256 bytes | 256 bytes |
| Operating Temperature | -40C to +105C | -40C to +105C | -40C to +105C |
Key Differentiators
- Functional Safety (FuSa) designation (vs ATMEGA4809-AFR)
- 3x the SRAM of the ATmega328P (vs ATMEGA328P-MU)
- Core Independent Peripherals reduce CPU loading (vs ATMEGA328PB-AUR)
Design Notes
The 48-UQFN (6x6 mm) package uses a fine 0.5 mm lead pitch and a center thermal pad. Extend the ground pad pattern on the PCB with a via array (typically 4-9 vias) to the ground plane to improve heat dissipation and grounding. Place 100 nF decoupling capacitors at both VDD and VDDIO2 pins as close to the package as possible. Note that the 40-pin ATmega4809 variants leave PB[5:0] and PC[7:6] floating on the shared die - if you port layouts across packages, those pins must be configured as INPUT_DISABLE or with pull-ups enabled per the datasheet.
Reserve pin PA0 for the UPDI programming interface with a series resistor and test pad accessible on the assembled board, since UPDI shares the PA0 pin and cannot be used for other functions without blocking in-system programming. Route the four USARTs with consideration for baud-rate stability: for UART-heavy designs, use an external crystal on PA1/PA2 (TOSC/XTAL) to maintain stable baud rates as recommended in community port guides, rather than relying solely on the internal oscillator for multi-node bus timing.
Supply the device from a clean 2.7 V to 5.5 V rail; the MCU is fully specified at 20 MHz only at the upper voltage range, so consult the frequency-versus-voltage derating curve in the ATmega4808/4809 datasheet (DS40002173B) when running at 3.3 V. Estimated: at 5 V and typical active current in the low-mA range, dissipation is a few tens of milliwatts and no heatsinking is needed; the UQFN thermal pad to ground plane provides adequate thermal relief. Add bulk capacitance (4.7-10 uF) near VDD for sleep/wake transient loads.
Compliance Information
RoHS compliance per Microchip standard product policy and DigiKey listing; obtain formal REACH/halogen-free declarations from Microchip product page certificates.
