ATMEGA164A-MU - 8-bit AVR MCU 16KB Flash 20MHz VQFN-44 | Microchip
MPN: ATMEGA164A-MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.68 | $4.68 |
| 10 | $4.21 | $42.10 |
| 100 | $3.75 | $375.00 |
| 500 | $3.36 | $1,680.00 |
| 1,000 | $3.01 | $3,010.00 |
ATMEGA164A-MU Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers, UARTs, and ADCs onto one die. The ATmega164A belongs to the ATmega family, which sits within the broader AVR 8-bit microcontroller product line - itself part of the general-purpose MCU hierarchy within power-embedded system design. By executing powerful instructions in a single clock cycle, the AVR enhanced RISC architecture achieves throughputs close to 1 MIPS per MHz, minimizing the trade-off between processing power and power consumption.
Key features include 16 KB of in-system self-programmable FLASH with read-while-write capability, 133 powerful instructions with most executing in a single clock cycle, 32 general-purpose working registers, a real-time counter (RTC), and four flexible timer/counters with compare modes and PWM. Internal calibrated oscillator, watchdog timer, and brown-out detection eliminate external components.
Technically, the Harvard architecture separates program and data buses, allowing simultaneous access for single-cycle instruction fetch and execution. The JTAG interface (per family documentation) supports on-chip debugging and boundary-scan, while the SPI and 8-channel 10-bit ADC extend analog and digital connectivity for sensor-intensive designs.
Typical applications include industrial control and automation nodes, consumer appliances, battery-powered instrumentation, and embedded control in HVAC and metering systems where a 44-pin VQFN footprint and 2.7V to 5.5V supply range simplify design reuse.
A key design consideration is supply voltage versus clock speed: full 20 MHz operation typically requires the higher end of the 2.7V to 5.5V supply range, so derate the clock for low-voltage battery designs to guarantee timing margin.
This page synthesizes distributor pricing, drop-in alternatives within the ATmega family, and practical design notes not consolidated in the manufacturer datasheet summary.
Drop-in alternatives for ATMEGA164A-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 ATMEGA164A-MU (same form factor and footprint) β differing in Package, Flash Memory, ADC, Operating Temperature, Communication Interfaces.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA324A-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA644A-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1284P-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
Contact for price
View Datasheet βATMEGA164PA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.55 / Unit
View Datasheet βATMEGA324PA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164A-MU Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Program Memory (FLASH) | 16 KB (8K x 16) ISP |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Throughput | Up to 20 MIPS (approx. 1 MIPS per MHz) |
| Instruction Set | 133 powerful instructions, most single-cycle |
| Supply Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O | 32 I/O lines |
| General Purpose Registers | 32 |
| ADC | 10-bit ADC (per family datasheet) |
| Peripherals | Real-time counter, timers/PWM, WDT, brown-out detection |
| Programming Interface | ISP (In-System Programmable), read-while-write |
| Package | 44-VQFN (7x7 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| Life Cycle Stage | Active |
ATMEGA164A-MU 44-vqfn (7x7 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATMEGA164A-MU (44-vqfn (7x7 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 ATMEGA164A-MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA164A-MU is suitable for 6 applications: Industrial Control and Automation, Sensor Nodes and Data Acquisition, Consumer Appliance Control, Battery-Powered Portable Instruments, HVAC and Building Automation, Metering and Energy Monitoring.
Industrial Control and Automation
The ATMEGA164A-MU suits industrial control nodes because its AVR core delivers close to 1 MIPS per MHz, giving deterministic single-cycle execution for scan-loop and sequencing tasks, while 16 KB of ISP FLASH accommodates ladder-style or state-machine firmware with room for a serial bootloader. The industrial -40C to +85C temperature rating and 2.7V to 5.5V supply range tolerate noisy 24V-panel derived rails after simple regulation. Its 32 GPIO lines directly drive relays, optocoupled inputs, and status LEDs through the four 8-bit ports, and the watchdog timer plus brown-out detection provide the fault recovery behavior expected in unattended factory equipment. The VQFN-44 exposed-pad package also improves thermal and ground integrity on multi-layer industrial PCBs.
Recommended
Sensor Nodes and Data Acquisition
For sensor acquisition nodes, the ATMEGA164A-MU combines an integrated 10-bit ADC with 1 KB SRAM and 512 B EEPROM, allowing local calibration constants to persist across power cycles without external memory. The AVR core processes sample streams at 20 MIPS maximum throughput, sufficient for filtering and thresholding in vibration, temperature, and level monitoring, while the real-time counter supports time-stamped logging. Operating from 2.7V enables direct use of three-cell battery stacks with a simple LDO or buck front end. SPI connectivity links external precision converters or SD-card storage, and in-system programmable FLASH lets field units receive firmware updates over a two-wire ISP header. The compact 44-pin VQFN (7x7 mm) keeps node PCB area small for embedded installations.
Recommended
Consumer Appliance Control
Consumer appliance boards - coffee machines, air conditioners, small white goods - frequently adopt the ATMEGA164A-MU because the internal calibrated oscillator eliminates a crystal in non-timing-critical designs, reducing BOM cost, while the 16 KB FLASH holds UI state machines, touch/button handling, and display drivers with headroom. The 32 GPIO lines segment a multiplexed seven-segment or LCD driver layout across four ports, and timer PWM channels generate fan, heater, and motor triac control at zero-cross-referenced rates. The 2.7V to 5.5V supply tolerance simplifies transformerless or flyback-derived supplies, and brown-out detection prevents EEPROM corruption during mains dips. The exposed-pad VQFN-44 offers robust solder joints against thermal cycling typical in appliances.
Recommended
Battery-Powered Portable Instruments
Portable instruments benefit from the ATmega164A architecture's single-cycle instruction execution, which lets the CPU finish work quickly and return to sleep modes, stretching battery life between charges. The picoPower ATMEGA164PA-MU, a pin-compatible variant, further reduces active and sleep current when the power budget is tight. The integrated 10-bit ADC reads user interface potentiometers and sensor inputs without an external converter, the EEPROM stores user calibrations, and the watchdog timer guards against lockups in the field. Operation across the 2.7V to 5.5V range supports two- or three-cell alkaline or single-cell lithium configurations with regulation. The 7x7 mm VQFN footprint fits handheld enclosures where board space is the dominant constraint.
Recommended
HVAC and Building Automation
HVAC controllers use the ATMEGA164A-MU for thermostat logic, damper and valve actuation, and sensor polling because its 32 GPIO and multiple timer/PWM channels handle multi-zone I/O in a single 44-pin device. The 16 KB FLASH supports Modbus-style UART communication stacks with room to spare, and the 512 B EEPROM retains setpoints and schedules through power outages. Industrial temperature rating covers rooftop and mechanical-room environments, and the 2.7V to 5.5V operating range pairs with simple AC-derived power supplies. Brown-out detection plus watchdog recovery ensure the controller restarts cleanly after brownouts common in building electrical systems, and the VQFN exposed pad improves EMI behavior on control boards near switching relays.
Recommended
Metering and Energy Monitoring
Energy meters and submeters leverage the ATMEGA164A-MU's 10-bit ADC and precise timer capture peripherals to sample current and voltage waveforms, while 1 KB SRAM buffers accumulation data between writes to the 512 B EEPROM, which holds tamper flags and lifetime registers. The AVR core's 20 MIPS peak throughput executes fixed-point power calculations in the sampling loop, and the UART forwards readings to a gateway over RS-485 via an external transceiver. Industrial temperature range suits outdoor meter cabinets, and the green RoHS-compliant VQFN-44 package aligns with utility procurement requirements. In-system programmable FLASH allows calibration tables and firmware to be updated after final assembly on the production line.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164A-MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA324A-MU | ATMEGA644A-MU | ATMEGA1284P-MUR | ATMEGA164PA-MU |
|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| FLASH Memory | 16 KB | 32 KB | 64 KB | 128 KB | 16 KB |
| SRAM | 1 KB | 2 KB | 4 KB | 16 KB | 1 KB |
| EEPROM | 512 B | 1 KB | 2 KB | 4 KB | 512 B |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V (picoPower) | 1.8 V to 5.5 V (picoPower) |
| Power Technology | Standard ATmega A-generation | Standard A-generation | Standard A-generation | picoPower | picoPower |
| Pin Compatibility | Baseline 44-pin VQFN pinout | Pin-to-pin compatible | Pin-to-pin compatible | Pin-to-pin compatible | Pin-to-pin compatible |
Key Differentiators
- Best cost position within the 44-pin VQFN ATmega family for 16 KB designs (vs ATMEGA324A-MU)
- Largest footprint-compatible memory ceiling available on the same board (vs ATMEGA1284P-MUR)
- Lower unit cost than the picoPower variant at the same capacity (vs ATMEGA164PA-MU)
Design Notes
The ATMEGA164A-MU specifies a 2.7 V to 5.5 V supply, but the maximum 20 MHz clock is only valid toward the upper end of the range per the family speed-grade curves. Estimated: for a 3.3 V design, verify the datasheet safe-operating frequency curve before locking the clock; if full speed is required at 3.3 V, consider the picoPower ATMEGA164PA-MU, which extends the supply floor toward 1.8 V. Decouple VCC and AVCC independently with 100 nF ceramic capacitors placed within 5 mm of each pin, and tie AVCC to VCC through an RC filter (Estimated: 10 ohm + 100 nF) when using the ADC in noisy switching environments.
The 44-pin VQFN (7x7 mm) has an exposed pad that should be soldered to a grounded thermal land with an array of thermal vias - this improves ground integrity, heat dissipation, and mechanical reliability. QFN package inspection requires X-ray or side-view AOI because the leads are underneath the body; specify the PCB land pattern per the Microchip datasheet mechanical drawing rather than redrawing it, as QFN lead geometry errors are a common reflow-defect source. Keep the ISP programming header routed away from switching nodes, and place a 100 nF capacitor at each supply group (VCC, AVCC) plus bulk 10 uF near the regulator.
Three pitfalls recur in ATmega164A designs. First, firmware growth: 16 KB FLASH fills quickly once a bootloader and communication stack are added - leave at least 20% headroom or select the pin-compatible ATMEGA324A-MU at design-in time. Second, clock/voltage mismatch: running near 20 MHz at low battery voltage risks timing violations; consult the speed-grade table in the Microchip ATmega164A datasheet summary (Atmel-42712). Third, EEPROM wear: avoid writing calibration values every loop iteration - implement wear leveling or write only on change, since EEPROM endurance is finite per the datasheet.
To pass conducted emissions when driving relays or triacs from the ATMEGA164A-MU GPIO, add series 33-100 ohm resistors at port pins driving long wires to slow edge rates, and use the internal slew-limited port configuration where supported. Keep the crystal or internal-oscillator choice consistent: using the internal calibrated oscillator removes high-frequency harmonics near the MCU but sacrifices frequency accuracy (suitable for UART only within tolerance limits). Route ADC analog inputs away from PWM traces, and place a small RC anti-aliasing filter (Estimated: 1 kohm + 10 nF, ~1.6 kHz cutoff) at analog inputs sampled by the 10-bit ADC.
Compliance Information
FindIC family listing describes the part as Green, Tape & Reel (lead-free RoHS packaging). REACH, halogen-free and conflict-minerals declarations not present in verified data - request current certificates from Microchip.
