ATMEGA164A-MCH - 16KB AVR MCU 20MHz 44-QFN | Microchip
MPN: ATMEGA164A-MCH β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.65 | $1.65 |
| 10 | $1.48 | $14.80 |
| 100 | $1.38 | $138.00 |
| 500 | $1.3 | $650.00 |
| 1,000 | $1.22 | $1,220.00 |
ATMEGA164A-MCH Overview
An AVR ATmega microcontroller is a member of the microcontroller unit (MCU) family within the broader semiconductor hierarchy: MCU -> embedded processor -> integrated circuit. An MCU integrates a CPU core, program memory, data memory and peripherals (timers, serial interfaces, ADC) on one die, replacing multi-chip designs in embedded systems.
Key features include 32 general purpose I/O lines and 32 general purpose working registers directly connected to the ALU for fast single-cycle operation. The memory architecture supports read-while-write ISP FLASH, enabling firmware updates in the field. Peripherals include a real-time counter, multiple timers with PWM, a 10-bit ADC, USART, SPI and TWI (I2C) serial interfaces, and JTAG for on-chip debugging and boundary scan.
The advanced RISC Harvard architecture separates program and data buses, so instruction fetch and data access occur in parallel. Operating from a 2.7 V to 5.5 V supply range (per distributor listings), the device suits both 3.3 V and 5 V designs. Power management includes idle, power-down, power-save and standby sleep modes for battery-operated products.
Typical applications include industrial control and automation nodes, consumer appliances, battery-powered instrumentation, and embedded controllers requiring in-field ISP firmware updates. The 44-QFN footprint saves board area versus TQFP while the exposed pad improves ground and thermal performance.
Design consideration: choose the system clock carefully - full 20 MHz operation requires a 4.5 V to 5.5 V supply, while lower-voltage rails limit the maximum safe frequency.
This page synthesizes distributor pricing, drop-in alternatives, pinout guidance, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA164A-MCH 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-MCH (same form factor and footprint) β differing in ADC, Package, EEPROM, Flash Program Memory, Instructions.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA164P-20MU
β Drop-Inβ In Stock
$2.98 / Unit
View Datasheet βATMEGA324A-MCHR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA1284P-MUR
β Drop-Inβ In Stock
Contact for price
View Datasheet βATMEGA164PA-MCH
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164A-MCH Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 16 KB (8K x 16), ISP, read-while-write |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Peak Throughput | 20 MIPS at 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O | 32 lines |
| Working Registers | 32 x 8-bit |
| Package | 44-QFN (5x5 mm) with exposed pad |
| Mounting Type | Surface Mount |
| ADC | 10-bit ADC |
| Serial Interfaces | USART, SPI, TWI (I2C) |
| Debug / Scan | JTAG (on-chip debug and boundary scan) |
| Sleep Modes | Idle, Power-down, Power-save, Standby |
| Lifecycle Stage | Active |
ATMEGA164A-MCH 44-qfn (5x5 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATMEGA164A-MCH (44-qfn (5x5 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-MCH.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA164A-MCH is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Instrumentation, Consumer Appliances and Home Automation, Embedded Systems Education and Prototyping, Sensor Interface and Data Acquisition Nodes, Motor Control and PWM Actuation.
Industrial Control and Automation
The ATMEGA164A-MCH fits industrial control nodes because its 20 MHz AVR core delivers 20 MIPS deterministic single-cycle execution, and its 32 GPIO lines with PWM-capable timers drive relays, contactors and actuators directly. The 10-bit ADC digitizes sensor feedback such as temperature, pressure and current while SPI and TWI interfaces link panel displays and peripheral modules. JTAG enables boundary-scan test and on-chip debugging during production, and the industrial 2.7 V to 5.5 V supply range supports 5 V PLC backplanes. Field firmware updates run over USART bootloaders thanks to read-while-write ISP FLASH, allowing control logic revision without desoldering the 44-QFN package.
Recommended
Battery-Powered Instrumentation
For portable and battery-powered instruments, the ATMEGA164A-MCH offers sleep modes (idle, power-down, power-save, standby) that drop supply current to microamp levels between measurements, extending battery life substantially. The 10-bit ADC samples sensor channels and the internal real-time counter maintains a wake calendar for periodic logging. Its 1 KB SRAM buffers data records while the 512 B EEPROM stores calibration constants that survive power loss. The compact 5x5 mm 44-QFN footprint suits handheld enclosures, and 2.7 V operation allows two-cell or single-cell-boosted rails. Where the lowest sleep current is critical, footprint-identical PicoPower variants such as ATMEGA164PA-MCH provide improved power figures without layout change.
Recommended
Consumer Appliances and Home Automation
The ATMEGA164A-MCH serves appliance and smart-home controller boards where a 5 V or 3.3 V embedded controller must sequence loads, scan a key matrix and drive a segment LCD or LED display. Single-cycle AVR instructions keep button debouncing and display refresh responsive without an RTOS, while PWM timers generate motor and heater drive signals. The TWI (I2C) bus connects environmental sensors and EEPROM expansion, and the USART links to Wi-Fi or radio co-processor modules. With 16 KB FLASH there is ample room for protocol stacks plus product logic, and in-field ISP updates let manufacturers ship fixes through service ports on the deployed 44-QFN device.
Recommended
Embedded Systems Education and Prototyping
The ATMEGA164A-MCH is a strong teaching and prototyping MCU: the AVR RISC instruction set with 32 working registers is simple to program in C or assembly, and the single-cycle execution model makes timing behavior transparent to students. On-chip JTAG supports step-by-step debugging with low-cost tools, and ISP FLASH programming needs only a few header pins, so lab boards tolerate repeated re-flashing. The 44-QFN exposed-pad package demonstrates professional surface-mount assembly, while pin-compatible upgrades to ATMEGA324A or ATMEGA1284P let the same PCB grow with project complexity. The 20 MIPS core is fast enough for real-time lab experiments in control, communication and signal sampling.
Recommended
Sensor Interface and Data Acquisition Nodes
In distributed sensing and DAQ nodes, the ATMEGA164A-MCH pairs its 10-bit ADC with an analog comparator and precision timers to digitize up to eight multiplexed channels, while the 1 KB SRAM and 512 B EEPROM hold sample frames and configuration data locally. SPI streams raw samples to external flash or to a host controller, and the USART forwards processed results over RS-485 or radio links. Sleep modes allow duty-cycled acquisition where the node wakes on a timer interrupt, samples, transmits and returns to power-down - a pattern that multiplies battery life in remote monitoring. Operating down to 2.7 V enables direct connection to three-cell supply rails without a regulator stage.
Recommended
Motor Control and PWM Actuation
The ATMEGA164A-MCH drives small DC and stepper motors using its PWM-capable timer outputs; at 20 MHz the PWM resolution and update rate are sufficient for smooth speed and position control of fans, pumps and actuators. Quadrature or Hall feedback enters through GPIO and the analog comparator for zero-crossing detection in sensorless schemes, and the ADC reads current-sense shunts for protection loops. The 5 V supply range directly drives MOSFET gate circuitry, simplifying the power stage. Fast, deterministic interrupt latency from the single-cycle AVR core keeps commutation timing tight. Designs needing more code for advanced control laws can drop in the pin-compatible ATMEGA324A-MCHR without PCB rework.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164A-MCH β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164P-20MU | ATMEGA324A-MCHR | ATMEGA1284P-MUR | ATMEGA164A-AU |
|---|---|---|---|---|---|
| Package | 44-QFN (5x5 mm) EP | 44-QFN (5x5 mm) - same | 44-QFN (5x5 mm) - same | 44-QFN (5x5 mm) - same | 44-TQFP - different (not drop-in) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 32 KB | 128 KB | 16 KB |
| Core | 8-bit AVR RISC | 8-bit AVR RISC | 8-bit AVR RISC | 8-bit AVR RISC | 8-bit AVR RISC |
| Drop-in on Same Footprint | Reference | Yes - pin-to-pin | Yes - pin-to-pin | Yes - pin-to-pin | No - TQFP land pattern differs |
Key Differentiators
- Lowest-cost entry point of the pin-compatible 44-QFN ATmega family (vs ATMEGA324A-MCHR)
- Memory upgrade path without PCB change (vs ATMEGA1284P-MUR)
- PicoPower alternative for battery designs (vs ATMEGA164P-20MU / ATMEGA164PA-MCH)
Design Notes
The 44-QFN (5x5 mm) package has an exposed pad on the bottom that serves as the primary ground connection. The PCB land pattern must include a central thermal pad soldered to a ground array of vias (typically a 3x3 via pattern) to the internal ground plane. Verify stencil apertures around 50-70% coverage to avoid voiding under the pad - poor exposed-pad soldering is the most common QFN assembly defect and shows up as intermittent ground faults rather than clean failures.
Respect the AVR frequency-versus-voltage safe operating area: 20 MHz operation is only specified at the top of the 2.7 V to 5.5 V supply range, while 3.3 V rails require a reduced maximum clock. Decouple VCC and AVCC individually with 100 nF ceramic capacitors placed within 2 mm of each pin pair, plus one bulk 10 uF per rail. Separate analog and digital ground returns and connect them at a single point near the exposed pad to preserve 10-bit ADC accuracy.
Do not confuse package suffixes: -MCH is 44-QFN while -AU is 44-TQFP; they are not footprint interchangeable. Also confirm the reset pin configuration and JTAG enable fuse state - JTAG is enabled by default on this family and claims four port-C pins, so disable via fuse if those GPIO are needed. When migrating to ATMEGA324A or ATMEGA1284P drop-ins, check fuse defaults and EEPROM size differences before reusing programming scripts.
Keep the crystal within 10 mm of the XTAL pins with short direct traces and place load capacitors' ground returns close to the device ground. For SPI clocks above 8 MHz, route clock lines away from the ADC input traces to avoid coupling noise into analog samples. Use the internal pull-ups sparingly on TWI lines - external 4.7 kOhm resistors give more predictable I2C rise times at bus capacitance above 100 pF.
Compliance Information
Compliance status was not present in the provided verified data; confirm on the official Microchip product page before regulatory sign-off.
