ATMEGA164PA-MCHR - 8-bit AVR MCU 16KB Flash 20MHz | Microchip
MPN: ATMEGA164PA-MCHR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.92 | $3.92 |
| 10 | $3.53 | $35.30 |
| 100 | $3.13 | $313.00 |
| 500 | $2.86 | $1,430.00 |
| 1,000 | $2.71 | $2,710.00 |
ATMEGA164PA-MCHR Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle, delivering throughput approaching 1 MIPS per megahertz. Within the power management and embedded control hierarchy, MCUs such as this sit at the node between raw logic devices and application processors, handling sensing, timing, and communication tasks in embedded systems.
Key differentiating features include read-while-write flash for in-system programming, picoPower low-power technology for battery-operated designs, three flexible timer/counters with compare modes and PWM, and a real-time counter. Two USARTs enable multi-channel serial communication, while a byte-oriented Two-Wire serial interface (TWI/I2C) and SPI support peripheral expansion.
Technical depth comes from the advanced AVR RISC architecture: 133 powerful instructions, most single-cycle, with 32 general purpose working registers directly connected to the ALU. This register-file-to-ALU connection eliminates the accumulator bottleneck of conventional 8-bit MCUs and allows system designers to optimize power consumption versus processing speed.
Typical applications include industrial control nodes, consumer appliance controllers, sensor interface boards, and battery-powered metering products where the 10-bit ADC and picoPower sleep modes reduce system cost and energy use.
A key design consideration: the 44-QFN package requires careful exposed-pad grounding for thermal and signal integrity, and the 20MHz maximum clock at 4.5-5.5V must be derated at lower supply voltages.
This page synthesizes distributor pricing, drop-in alternatives within the ATmega family, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA164PA-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 ATMEGA164PA-MCHR (same form factor and footprint) — differing in Package, ADC, Flash Memory, Throughput, Instruction Set.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA164P-20MUR
✅ Drop-In✓ In Stock
$1.5 / Unit
View Datasheet →ATMEGA164P-20MQ
✅ Drop-In✓ In Stock
$2.96 / Unit
View Datasheet →ATMEGA164A-MU
✅ Drop-In✓ In Stock
$3.01 / Unit
View Datasheet →ATMEGA1284P-MUR
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ATMEGA164PA-MCHR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 16 KB (8K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O Lines | 32 |
| USART Interfaces | 2 |
| Two-Wire Interface (TWI/I2C) | 1 |
| Timers/Counters | 3 flexible timer/counters with compare modes and PWM |
| ADC | 8-channel 10-bit |
| Low Power Technology | picoPower |
| In-System Programming | ISP flash with read-while-write |
| Instructions | 133 powerful instructions, most single-cycle |
| Package | 44-VQFN (5x5 mm), exposed pad |
| Mounting Type | Surface Mount |
ATMEGA164PA-MCHR Pin Configuration
| Pin 1 | PA4 (ADC4) — Port A bit 4 / ADC channel 4 |
| Pin 2 | PA5 (ADC5) — Port A bit 5 / ADC channel 5 |
| Pin 3 | PA6 (ADC6) — Port A bit 6 / ADC channel 6 |
| Pin 4 | PA7 (ADC7) — Port A bit 7 / ADC channel 7 |
| Pin 5 | AGND — Analog ground |
| Pin 6 | AVCC — Analog supply for ADC |
| Pin 7 | PC7 — Port C bit 7 |
| Pin 8 | PC6 — Port C bit 6 |
| Pin 9 | PC5 — Port C bit 5 |
| Pin 10 | PC4 — Port C bit 4 (TWI SDA) |
| Pin 11 | PC3 — Port C bit 3 |
| Pin 12 | PC2 — Port C bit 2 |
| Pin 13 | PC1 — Port C bit 1 |
| Pin 14 | PC0 — Port C bit 0 (TWI SCL) |
| Pin 15 | PD7 — Port D bit 7 |
| Pin 16 | PD6 — Port D bit 6 |
| Pin 17 | PD5 — Port D bit 5 |
| Pin 18 | PD4 — Port D bit 4 (USART1) |
| Pin 19 | PD3 — Port D bit 3 |
| Pin 20 | PD2 — Port D bit 2 (INT0) |
| Pin 21 | PD1 — Port D bit 1 (USART TXD0) |
| Pin 22 | PD0 — Port D bit 0 (USART RXD0) |
| Pin 23 | VCC — Digital supply |
| Pin 24 | GND — Digital ground |
| Pin 25 | PB0 (SS) — Port B bit 0 / SPI slave select |
| Pin 26 | PB1 — Port B bit 1 |
| Pin 27 | PB2 — Port B bit 2 |
| Pin 28 | PB3 (MOSI) — Port B bit 3 / SPI MOSI |
| Pin 29 | PB4 (MISO) — Port B bit 4 / SPI MISO |
| Pin 30 | PB5 (SCK) — Port B bit 5 / SPI clock |
| Pin 31 | PB6 (XTAL1) — Port B bit 6 / crystal input |
| Pin 32 | PB7 (XTAL2) — Port B bit 7 / crystal output |
| Pin 33 | RESET — Reset input (active low) |
| Pin 34 | VCC — Digital supply |
| Pin 35 | GND — Digital ground |
| Pin 36 | PD5/T1 alternate — Timer/counter function pin (per datasheet 44-pin figure) |
| Pin 37 | PD4/XCK alternate — USART external clock function pin (per datasheet 44-pin figure) |
| Pin 38 | PA0 (ADC0) — Port A bit 0 / ADC channel 0 |
| Pin 39 | PA1 (ADC1) — Port A bit 1 / ADC channel 1 |
| Pin 40 | PA2 (ADC2) — Port A bit 2 / ADC channel 2 |
| Pin 41 | PA3 (ADC3) — Port A bit 3 / ADC channel 3 |
| Pin 42 | AREF — ADC analog reference input |
| Pin 43 | GND — Ground |
| Pin 44 | AVCC — Analog supply |
Typical Applications
ATMEGA164PA-MCHR is suitable for 6 applications: Industrial Control Nodes, Battery-Powered Metering, Consumer Appliance Controllers, Sensor Interface and Data Acquisition, Embedded Communication Adapters, Hobbyist and Maker Embedded Systems.
Industrial Control Nodes
The ATMEGA164PA-MCHR fits industrial control nodes that need deterministic timing and robust serial links. Its 20MHz AVR core delivers approximately 1 MIPS/MHz throughput, while three timer/counters with compare modes generate PWM for actuators and precise event timing. Dual USARTs allow simultaneous fieldbus and diagnostic links, and the TWI interface manages remote I/O expanders. The 44-VQFN exposed-pad package grounds solidly to industrial PCBs, and 2.7-5.5V operation tolerates regulated 3.3V or 5V rails. The 8-channel 10-bit ADC reads analog process sensors directly, reducing external component count in PLC-adjacent monitoring boards.
Recommended
Battery-Powered Metering
Battery metering benefits directly from the picoPower technology in the ATMEGA164PA-MCHR. The real-time counter maintains timekeeping while the CPU sleeps, and multiple sleep modes let firmware duty-cycle the 20MHz core so average current is dominated by microamp-level sleep current rather than active execution. The 8-channel 10-bit ADC samples current and voltage sense front-ends without an external converter, and 512B EEPROM stores calibration and consumption logs that survive power loss. With 16KB flash, both metrology firmware and a communication stack fit on-chip, and the 44-QFN 5x5 mm footprint suits compact meter housings.
Recommended
Consumer Appliance Controllers
Consumer appliance control boards - from coffee machines to HVAC user interfaces - are a strong fit for the ATMEGA164PA-MCHR. Thirty-two GPIO lines drive keypads, LEDs, relays, and stepper or fan controls directly; PWM outputs from the three timer/counters dim displays and control motor speed efficiently. The hardware TWI bus interfaces touch controllers or EEPROM peripherals, while a USART handles factory test and firmware update links. The industrial temperature grading and 2.7-5.5V supply cover appliance rail tolerances, and the 5x5 mm VQFN with exposed pad keeps controller PCBs small and cost-optimized for volume production.
Recommended
Sensor Interface and Data Acquisition
The ATMEGA164PA-MCHR serves as a compact sensor-interface MCU where multiple analog channels converge. Its 8-channel 10-bit ADC, multiplexed across the port-A pins, digitizes temperature, pressure, and level sensors without external front-end converters for mid-accuracy applications. The SPI and TWI buses add higher-resolution external ADCs or digital sensors, and dual USARTs stream processed readings to a host or radio module. Timer-driven sampling produces regular conversion intervals for FFT-ready or averaging firmware. The picoPower sleep modes suit intermittently powered sensor nodes, and 1KB SRAM buffers enough samples for local filtering before transmission.
Recommended
Embedded Communication Adapters
Protocol-adapter and gateway boards exploit the ATMEGA164PA-MCHR's dual USARTs: one channel interfaces a field device (RS-485 or RS-232 via external transceiver) while the second talks to a host or radio. The TWI and SPI hardware masters handle EEPROM, RTC, and peripheral expansion concurrently with serial traffic, and the 16KB ISP flash with read-while-write supports bootloader-based field firmware updates. Timer capture/compare functions decode or generate timing-critical signals. The compact 44-VQFN package fits dongle-format adapters, and the AVR single-cycle instruction set keeps interrupt latency low for reliable framing at standard UART baud rates.
Recommended
Hobbyist and Maker Embedded Systems
The AVR ecosystem, mature ISP tooling, and free GCC toolchain make the ATMEGA164PA-MCHR attractive to makers upgrading from ATmega328-class parts. Thirty-two GPIO and 16KB flash provide headroom for robotics, display, and automation projects that outgrow smaller AVRs, while dual USARTs support simultaneous Bluetooth/Wi-Fi module and debug connections. ICSP programming with MPLAB SNAP or USBasp requires only SPI plus RESET, and debugWIRE enables on-chip debugging through the reset line. The exposed-pad QFN requires a hot-plate or reflow process rather than hand soldering; hobbyists preferring socketed parts should use the TQFP ATMEGA164PA-AUR instead.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164PA-MCHR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164P-20MUR | ATMEGA164A-MU | ATMEGA1284P-MUR |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-VQFN (5x5 mm) exposed pad | 44-VQFN (MLF) - same | 44-VQFN (MLF) - same | 44-VQFN (MLF) - same |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Flash Memory | 16 KB | 16 KB | 16 KB | 128 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 16 KB |
| EEPROM | 512 B | 512 B | 512 B | 4 KB |
| picoPower Technology | Yes (PA version) | No (P version) | No (A version) | No (P version) |
| GPIO | 32 | 32 | 32 | 32 |
Key Differentiators
- picoPower low-power technology (vs ATMEGA164P-20MUR)
- Memory-upgrade path without respin (vs ATMEGA1284P-MUR)
- Exposed-pad QFN over TQFP (vs ATMEGA164PA-AUR)
Design Notes
The 44-QFN 5x5 mm exposed pad is the primary ground connection for the ATMEGA164PA-MCHR. Solder it to a ground plane array of 5x5 via stitches (estimated: 9-25 vias under the pad) to achieve both low inductance and acceptable thermal dissipation. Per Microchip MLF package application guidance, printed the exposed pad with a slightly reduced stencil opening (50-70% coverage) to avoid excessive solder paste that can float the chip during reflow and bridge the perimeter pads.
Provide independent decoupling on the digital VCC pins and the AVCC/AGND pair. Estimated typical practice: 100nF X7R ceramic within 2mm of each VCC pin plus 4.7-10uF bulk per rail. Connect AVCC to VCC through an LC or RC filter when ADC accuracy matters, because switching noise on AVCC directly degrades the 10-bit converter's effective resolution. Keep the AGND pin tied to a quiet analog ground island connected to the main plane at one point.
AVR clock frequency depends on supply voltage: 20MHz operation is only valid at the upper end of the 2.7-5.5V range. Derate f_MAX per the datasheet speed-grade curve when running from a 3.3V rail. Also verify fuse settings (CKSEL, CKDIV8, BOOTRST) before first power-up - an incorrect clock fuse selection on a QFN part is difficult to recover, so enable debugWIRE or ISP access on the RESET/SPI pins and never repurpose RESET as GPIO unless recovery via 12V parallel programming is acceptable to your process.
Compliance Information
Retrieved distributor data did not include explicit compliance certificate text; confirm RoHS/REACH declarations on the Microchip product page. Industrial temperature grade indicated in Mouser listing.
