ATMEGA164A-MCHR - 8-bit AVR MCU 16KB Flash 20MHz QFN-44 | Microchip
MPN: ATMEGA164A-MCHR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.6 | $4.60 |
| 10 | $4.14 | $41.40 |
| 100 | $3.72 | $372.00 |
| 500 | $3.35 | $1,675.00 |
| 1,000 | $3.01 | $3,010.00 |
ATMEGA164A-MCHR Overview
A microcontroller unit (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals on one die. The ATmega164A belongs to the AVR 8-bit microcontroller family, sitting below the ATmega324A/644A/1284 within the megaAVR product hierarchy of Microchip Technology.
Key features include the AVR enhanced RISC architecture executing 133 powerful instructions, most in a single clock cycle, delivering throughput approaching 1 MIPS per MHz. The 16 KB Flash supports read-while-write ISP programming, and the device integrates a real-time counter, four flexible timer/counters with compare modes and PWM, and general-purpose I/O lines (32 per Microchip product page).
Architecturally, the ATmega164A uses a Harvard structure with 32 general-purpose working registers directly connected to the ALU, allowing two independent instructions to execute in one cycle. The rich instruction set and single-cycle execution minimize code size and interrupt latency in embedded control loops.
Typical applications include industrial automation, home appliance control, sensor data acquisition, and embedded systems where 16 KB of program memory is sufficient. Development is supported by Microchip MPLAB tools and the open-source MightyCore Arduino hardware package.
Design consideration: the QFN (MLF) package exposes a large ground pad on the underside that must be soldered to a grounded PCB land pattern for reliable operation and thermal performance.
This page synthesizes verified distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA164A-MCHR — 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-MCHR (same form factor and footprint) — differing in Package, SRAM, ADC, Flash Memory, EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA164PA-MCHR
✅ Drop-In✓ In Stock
$2.71 / Unit
View Datasheet →ATMEGA324A-MCHR
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA1284P-MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATMEGA1281V-8MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.02 / Unit
View Datasheet →ATMEGA164A-MCHR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 16 KB (8K x 16) ISP Flash |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O | 32 I/O lines |
| General Purpose Working Registers | 32 registers |
| Instruction Set | 133 instructions, mostly single-cycle |
| Throughput | Up to 1 MIPS per MHz |
| Package | 44-QFN (MLF) 5x5 mm |
| Mounting Type | Surface Mount |
| Operating Temperature (Max) | 85 C |
| Packaging | Tape and Reel (R suffix) |
| Programming | In-System Programmable (ISP), read-while-write |
| Debug Interface | In-Circuit Debug via MPLAB SNAP (ICSP) |
| Lifecycle Status | Active |
ATMEGA164A-MCHR 44-qfn (mlf) 5x5 mm Pin Configuration Guide
Pin configuration for ATMEGA164A-MCHR (44-qfn (mlf) 5x5 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 ATMEGA164A-MCHR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA164A-MCHR is suitable for 6 applications: Industrial Automation Control, Home Appliance Control, Sensor Data Acquisition Systems, Embedded HMI and Display Control, IoT Sensor Nodes and Smart Home Devices, Hobbyist and Maker Development.
Industrial Automation Control
The ATMEGA164A-MCHR fits industrial automation nodes that need deterministic 8-bit control with moderate program memory. Its AVR core executes 133 mostly single-cycle instructions at up to 20 MHz, delivering roughly 20 MIPS peak, enough for closed-loop motor or valve control with PID routines in 16 KB of Flash. The 2.7 V to 5.5 V supply range allows direct operation from 5 V industrial rails, and the four timer/counters with PWM and compare modes drive actuators and measure encoder inputs without external logic. The 32 GPIO lines interface limit switches, relays, and status LEDs directly. Using the external crystal plus watchdog gives robust timing recovery after disturbances, an important consideration in factory-floor EMC environments.
Recommended
Home Appliance Control
Appliance control boards benefit from the ATMEGA164A-MCHR's combination of 16 KB self-programmable Flash, 512 B EEPROM for storing user settings, and 1 KB SRAM for state machines. The EEPROM retains calibration and preference data across power cycles without external memory. Its 44-QFN 5x5 mm package conserves PCB area in cost-driven appliance layouts, while the 2.7 V to 5.5 V range tolerates unregulated wall-transformer supplies. Timer/PWM peripherals generate buzzer tones, triac-phase-control delays, and display multiplexing. Because the Flash supports read-while-write ISP updates, firmware field upgrades are possible through a UART bootloader, reducing service cost. In-circuit debugging via MPLAB SNAP on two I/O pins plus reset shortens development cycles on production-like boards.
Recommended
Sensor Data Acquisition Systems
For multi-channel sensor acquisition, the ATMEGA164A-MCHR offers a 10-bit-class analog front-end support through its AVCC-supplied analog section, ADC input multiplexing, and low-noise design when clocked moderately. The 1 KB SRAM buffers sampled data before transmission over UART or SPI, and 32 GPIO lines handle sensor enable, channel-select, and interrupt inputs. The 20 MHz clock provides ample headroom for oversampling and digital filtering in firmware. The real-time counter supports timestamping of events for logging applications. Designers should decouple AVCC separately with an RC filter and use the internal noise canceler features described in the Microchip datasheet to maximize conversion accuracy in electrically noisy environments such as motor drives.
Recommended
Embedded HMI and Display Control
Driving segment LCDs, multiplexed 7-segment displays, or small OLED modules via SPI is a common ATmega164A role. Timer-generated interrupt ticks refresh display digits without CPU-blocking delays, while the 16 KB Flash accommodates font tables and menu structures. The 44-QFN package places 32 GPIO lines in a compact 5x5 mm area, freeing board space around the display connector. EEPROM stores brightness levels, language selection, and calibration constants. The read-while-write Flash permits storing event logs in program memory during operation. Design consideration: multiplexed displays draw pulsed currents, so size the 5 V regulator and decoupling for peak LED segment currents, and dedicate timer compare outputs to PWM dimming for consistent contrast.
Recommended
IoT Sensor Nodes and Smart Home Devices
Battery-aware smart home nodes use the ATMEGA164A-MCHR with a 3.3 V supply within its 2.7 V to 5.5 V operating range, pairing it with RF modules over SPI or UART. Selecting the picoPower ATMEGA164PA-MCHR substitute drops sleep current further for coin-cell designs on the identical PCB footprint, a zero-layout-change power optimization. Timer-based wakeups and the real-time counter implement duty-cycled sampling so the MCU sleeps between transmissions. The 16 KB Flash holds protocol stacks for simple telemetry, while the 512 B EEPROM stores device identity and network keys across battery swaps. For production, program the lock bits and disable debug pins after deployment to protect firmware, and verify brown-out detection fuse settings for reliable operation as the battery discharges.
Recommended
Hobbyist and Maker Development
The ATmega164A is fully supported by the open-source MightyCore Arduino hardware package covering ATmega1284, 644, 324, and 164 devices, letting makers use the Arduino IDE, sketches, and libraries on this chip. The 44-QFN package suits compact custom PCBs, while breakout adapters ease hand soldering. The 16 KB Flash and 1 KB SRAM run typical Arduino sketches comfortably, and the 20 MHz clock option (with the correct MightyCore board profile and fuse settings) outpaces classic 16 MHz boards by 25%. The MPLAB SNAP or a USBasp programmer loads bootloaders via ICSP using only two I/O pins plus reset. Beginners should confirm fuse bits for external crystal selection before first boot to avoid bricking the clock configuration.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164A-MCHR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164PA-MCHR | ATMEGA324A-MCHR | ATMEGA1284P-MUR | ATMEGA1281V-8MUR |
|---|---|---|---|---|---|
| Package | 44-QFN (MLF) 5x5 mm | 44-QFN (5x5 mm) - same | 44-QFN (5x5 mm) - same | 44-QFN (5x5 mm) - same | 44-QFN (5x5 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 32 KB | 128 KB | 128 KB |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 8 MHz |
| Core Variant | ATmega164A (standard) | ATmega164PA (picoPower) | ATmega324A (standard) | ATmega1284P (picoPower) | ATmega1281V (low-voltage) |
| Distributor Substitute Status | Active, not normally stocked (DigiKey) | DigiKey-designated parametric substitute, $4.60 unit | Listed in family cross-comparison | In XAIPART catalog | In XAIPART catalog |
Key Differentiators
- Baseline cost position in the pin-compatible family (vs ATMEGA324A-MCHR)
- Guaranteed parametric substitute availability (vs ATMEGA164PA-MCHR)
- Higher maximum clock than low-voltage family members (vs ATMEGA1281V-8MUR)
Design Notes
The 44-QFN (MLF) package has a large exposed die pad on the underside that must be connected to a grounded land pattern on the PCB. Do not treat it as an optional thermal relief: on many megaAVR designs this pad is the primary ground return, and leaving it unsoldered causes erratic resets and analog noise. Use a solder-mask-defined array of vias under the pad to tie it to the ground plane. Follow the Microchip AVR Hardware Design Considerations application note for stencil and via recommendations on MLF packages.
Supply the ATmega164A from a 2.7 V to 5.5 V rail and decouple VCC and AVCC independently, each with 100 nF ceramic capacitors placed within a few millimeters of the pins. If you use the ADC, filter AVCC through an RC network (for example 10 ohm and 1 uF) to isolate digital switching noise. Connect AGND to a quiet ground point. Verify the frequency-versus-voltage curve in the Microchip datasheet when running at the low end of the voltage range, since maximum safe clock scales with VCC.
Fuse-bit misconfiguration is the most common failure mode when migrating within the megaAVR family. When replacing ATMEGA164A-MCHR with ATMEGA164PA-MCHR, ATMEGA324A-MCHR, or ATMEGA1284P-MUR, the device signature changes, so update your programmer project settings or ISP programming script. Set fuses explicitly for external crystal (20 MHz requires the correct low-frequency/full-swing crystal setting), enable brown-out detection appropriate to the VCC range, and never set the clock fuses to external clock unless an oscillator signal is actually present, or the chip becomes unreachable.
Compliance Information
Compliance status not stated in the provided verified web data. Modern Microchip ATmega parts are typically RoHS-compliant, but this must be confirmed on the official Microchip ATmega164A product page before export documentation is issued.
