ATMEGA164PA-AU - 8-bit AVR MCU, 16KB Flash, 20MHz | Microchip
MPN: ATMEGA164PA-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.79 | $3.79 |
| 10 | $3.55 | $35.50 |
| 100 | $3.2 | $320.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.75 | $2,750.00 |
ATMEGA164PA-AU Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals, forming the lowest tier of the embedded computing hierarchy (embedded ICs -> microcontrollers -> 8-bit MCUs). The AVR family, originally developed by Atmel and now part of Microchip Technology, uses a Harvard architecture with single-cycle instruction execution, making 8-bit AVRs a benchmark for efficient, deterministic embedded control.
Key features of the ATMEGA164PA-AU include 32 general purpose I/O lines, three flexible 16/8-bit timer/counters with compare modes and PWM, two USARTs, a byte-oriented Two-Wire Interface (TWI/I2C), an 8-channel 10-bit ADC, and picoPower technology for sub-uA sleep currents. The device operates from 1.8V to 5.5V across the full 20 MHz frequency range.
Technically, the AVR core executes 131 powerful instructions, most in a single clock cycle, with 32 general purpose working registers directly connected to the ALU. An on-chip 2-cycle hardware multiplier accelerates DSP-style math. Self-programmable ISP FLASH with read-while-write support enables in-field firmware updates without an external programmer.
Typical applications include industrial control and sensing nodes, consumer appliances, battery-powered metering, and hobby/educational platforms compatible with the Arduino ecosystem.
Design consideration: choose the internal 8 MHz RC oscillator for cost-sensitive designs and reserve the external 20 MHz crystal for timing-critical UART or precision ADC work; always decouple AVCC separately from VCC for best ADC accuracy.
This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA164PA-AU 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 ATMEGA164PA-AU (same form factor and footprint) β differing in Package, Supply Voltage Range, ADC, EEPROM, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA164A-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA324PA-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA644PA-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA1284P-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA1284-AUR
β Drop-Inβ In Stock
$4.61 / Unit
View Datasheet βATMEGA164PA-AU Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Memory | 16 KB (8K x 16) ISP FLASH |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Throughput | Up to 20 MIPS at 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Number of I/O Lines | 32 |
| ADC | 8-channel, 10-bit |
| Timers/Counters | 3 (two 8-bit, one 16-bit) with PWM |
| USART | 2 |
| TWI (I2C) | Yes, byte-oriented |
| SPI | Yes |
| Instructions | 131, most single-cycle |
| Hardware Multiplier | On-chip 2-cycle multiplier |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Low Power Technology | picoPower |
| RoHS Status | Compliant (green package) |
ATMEGA164PA-AU Pin Configuration
| Pin 1 | PB5 β Port B5 / T1 / OC1A / PCINT13 |
| Pin 2 | PB4 β Port B4 / OC0A / PCINT12 |
| Pin 3 | PB3 β Port B3 / ADC0 / OC2A / PCINT11 |
| Pin 4 | PB2 β Port B2 / OC1B / INT2 / PCINT10 |
| Pin 5 | PB1 β Port B1 / T1 / CLKO / PCINT9 |
| Pin 6 | PB0 β Port B0 / XCK0 / T0 / PCINT8 |
| Pin 7 | VCC β Digital supply voltage |
| Pin 8 | GND β Ground |
| Pin 9 | PB6 β Port B6 / OC1B / PCINT14 |
| Pin 10 | PB7 β Port B7 / OC2B / OC0A / PCINT15 |
| Pin 11 | PD7 β Port D7 / OC2B / TO0 / PCINT31 |
| Pin 12 | PD6 β Port D6 / ICP1 / PCINT30 |
| Pin 13 | PD5 β Port D5 / OC1A / PCINT29 |
| Pin 14 | PD4 β Port D4 / XCK1 / TO1 / PCINT28 |
| Pin 15 | PD3 β Port D3 / INT1 / PCINT27 |
| Pin 16 | PD2 β Port D2 / INT0 / PCINT26 |
| Pin 17 | PD1 β Port D1 / TXD0 / PCINT25 |
| Pin 18 | PD0 β Port D0 / RXD0 / PCINT24 |
| Pin 19 | XTAL2 β Inverting oscillator output |
| Pin 20 | XTAL1 β Inverting oscillator input / external clock |
| Pin 21 | PC7 β Port C7 / TOSC2 / PCINT23 |
| Pin 22 | PC6 β Port C6 / TOSC1 / PCINT22 |
| Pin 23 | PC5 β Port C5 / TDI / PCINT21 |
| Pin 24 | PC4 β Port C4 / TDO / PCINT20 |
| Pin 25 | PC3 β Port C3 / TMS / PCINT19 |
| Pin 26 | PC2 β Port C2 / TCK / PCINT18 |
| Pin 27 | PC1 β Port C1 / SDA / PCINT17 |
| Pin 28 | PC0 β Port C0 / SCL / PCINT16 |
| Pin 29 | PA7 β Port A7 / ADC7 / SCK / PCINT7 |
| Pin 30 | PA6 β Port A6 / ADC6 / MISO / PCINT6 |
| Pin 31 | PA5 β Port A5 / ADC5 / MOSI / PCINT5 |
| Pin 32 | PA4 β Port A4 / ADC4 / PCINT4 |
| Pin 33 | PA3 β Port A3 / ADC3 / PCINT3 |
| Pin 34 | PA2 β Port A2 / ADC2 / PCINT2 |
| Pin 35 | PA1 β Port A1 / ADC1 / PCINT1 |
| Pin 36 | PA0 β Port A0 / ADC0 / PCINT0 |
| Pin 37 | AREF β Analog reference for ADC |
| Pin 38 | GND β Ground |
| Pin 39 | AVCC β Analog supply for ADC (decouple separately) |
| Pin 40 | VCC β Digital supply voltage |
| Pin 41 | NC β Not connected (per datasheet) |
| Pin 42 | NC β Not connected (per datasheet) |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
ATMEGA164PA-AU is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Metering and Sensing, Consumer Appliances, Arduino-Compatible Hobby and Education, Sensor Gateways and IoT Edge Nodes, Motor Control and PWM Actuation.
Industrial Control and Automation
The ATMEGA164PA-AU fits industrial control nodes that need deterministic 8-bit control, multiple UART links, and robust I/O. Its two USARTs allow simultaneous Modbus RTU communication and local diagnostics, while the 8-channel 10-bit ADC digitizes up to eight analog sensor inputs such as 4-20 mA conditioning outputs. Operating from 1.8V to 5.5V and tolerant of 20 MHz full-speed operation, it interfaces cleanly with 5V industrial logic and 3.3V co-processors alike. The three timers with PWM drive actuators and heater control loops; the on-chip 2-cycle hardware multiplier supports scaling math without a floating-point library. Wide availability across 12 distributors makes it a dependable choice for long-lived industrial BOMs.
Recommended
Battery-Powered Metering and Sensing
picoPower technology is the decisive parameter for battery-powered metering: the ATMEGA164PA-AU achieves sub-uA sleep currents in power-save mode while retaining an asynchronous real-time counter for timekeeping, waking periodically to sample meters via the 10-bit ADC. The 1.8V floor allows operation directly from two alkaline cells or a lithium thionyl chloride cell through end-of-discharge, eliminating a boost converter and its quiescent draw. EEPROM storage retains calibration and tariff data through battery replacement cycles, with 100k write endurance. Designers typically clock the device from the internal 8 MHz RC during active bursts, then drop to a 32.768 kHz crystal on TOSC1/TOSC2 for timed wake-up, maximizing energy-per-measurement.
Recommended
Consumer Appliances
In consumer appliances - coffee machines, fans, small heaters, dishwasher panels - the ATMEGA164PA-AU provides touch-button scanning, display driving, and motor PWM control in one low-cost 44-pin device. The 32 GPIO lines drive segment LCDs through external drivers or direct LED matrices, while three timers generate multiple independent PWM channels for blower and pump speed control. A 10-bit ADC reads NTC thermistors and user potentiometers. Its 20 MIPS core executes PID temperature loops with margin to spare, and the hardware TWI interfaces to humidity or pressure sensors. The TQFP-44 package handles the reflow profiles of high-volume consumer assembly and carries RoHS-compliant green packaging for global regulatory acceptance.
Recommended
Arduino-Compatible Hobby and Education
The ATMEGA164PA-AU is a popular choice in the Arduino ecosystem through the MightyCore board support package, giving makers 44 pins - roughly double the I/O of an ATmega328P Uno - with familiar AVR programming in the Arduino IDE. The dual USARTs let one port drive a USB-serial bridge while the second talks to GPS or Bluetooth modules. Eight ADC channels and hardware PWM suit robotics and sensor-gateway builds. Because it ships blank, hobbyists burn the Optiboot-style bootloader with a USBasp or an Arduino-as-ISP; thereafter uploads run over serial. Its 16 KB FLASH accommodates typical sketches, and the pin-compatible 324PA/644PA/1284P family offers a free upgrade path when projects outgrow the memory.
Recommended
Sensor Gateways and IoT Edge Nodes
For wired IoT edge nodes that do not need an RF SoC, the ATMEGA164PA-AU aggregates sensors over TWI (I2C) and SPI and forwards data on one or both USARTs to a cellular or Ethernet modem. The picoPower sleep modes keep duty-cycled nodes within tight energy budgets, while 1 KB SRAM handles framed sensor packets and a lightweight ring buffer. The 10-bit ADC supports on-board supply and temperature monitoring; an external precision ADC can be attached via SPI when 10 bits are insufficient. Designers value the wide 1.8V-5.5V operating range, which lets the MCU track a collapsing battery and negotiate with 3.3V modems without level shifters when run from a common rail.
Recommended
Motor Control and PWM Actuation
The ATMEGA164PA-AU drives small DC motors, fans, and RC-style servos using its three timers with compare-mode PWM outputs distributed across Port B and Port D. Hardware PWM keeps jitter off the CPU, letting the 20 MIPS core run PID loops, encoder decoding on external interrupts INT0/INT1, and communication concurrently. The 2-cycle hardware multiplier accelerates the fixed-point arithmetic typical of motor control. A 10-bit ADC samples current shunts and back-EMF for sensorless speed estimation. Operating to 5.5V allows direct gate-drive logic for low-side MOSFET drivers from a 5V rail, and the 44-pin TQFP leaves enough GPIO for limit switches, enable lines, and a debugging UART simultaneously.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164PA-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164A-AU | ATMEGA324PA-AU | ATMEGA644PA-AU | ATMEGA1284P-AU |
|---|---|---|---|---|---|
| Package | TQFP-44 (10x10 mm) | TQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same | TQFP-44 (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 32 KB | 64 KB | 128 KB |
| SRAM | 1 KB | 1 KB | 2 KB | 4 KB | 16 KB |
| EEPROM | 512 B | 512 B | 1 KB | 2 KB | 4 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| picoPower Technology | Yes | No | Yes | Yes | Yes |
| Peripherals (ADC/USART/TWI) | 8-ch 10-bit ADC, 2 USART, TWI | 8-ch 10-bit ADC, 2 USART, TWI | 8-ch 10-bit ADC, 2 USART, TWI | 8-ch 10-bit ADC, 2 USART, TWI | 8-ch 10-bit ADC, 2 USART, TWI |
Key Differentiators
- picoPower technology for battery designs (vs ATMEGA164A-AU)
- Best price-per-feature in the same footprint (vs ATMEGA324PA-AU)
- Identical PCB footprint across five memory densities (vs ATMEGA1284P-AU)
- Dual USARTs standard across the family (vs ATMEGA164A-AU)
Design Notes
Decouple AVCC (pin 39) separately from VCC through an LC filter (10 uH inductor or ferrite bead plus 100 nF ceramic) and connect AVCC to VCC even when the ADC is unused, as required by the Microchip ATmega164A/PA datasheet. This keeps ADC switching noise out of the analog domain and preserves 10-bit conversion accuracy. Add a 100 nF capacitor at each VCC pin (7 and 40) placed within 5 mm of the pin with a solid via to the ground plane.
Keep the analog reference path clean: place a 100 nF capacitor on AREF (pin 37) and route it away from USART and crystal traces. If using the internal 1.1V bandgap reference for battery monitoring, remember conversions settle slowly - discard the first result after switching references, a documented behavior in Microchip's AVR datasheet family documentation. On a 4-layer board, allocate a continuous ground plane under the TQFP and stitch the exposed fan-out vias around the package perimeter.
The ATMEGA164PA-PU (PDIP) variant is obsolete per DigiKey forum reports - do not specify it for new designs; the -AU TQFP remains active. Also, the ATmega164/324/644/1284 family is NOT register-compatible with the ATmega16 classic part despite the similar name: port mapping, extended I/O registers, and fuse names differ, and code needs porting. Finally, at 5V do not exceed the 20 MHz rating, and when running below 1.8 V the device will brown-out - set the BOD fuse appropriately for your supply rail.
For the external 20 MHz crystal on XTAL1/XTAL2, follow the datasheet-recommended load: place the crystal within 10 mm of the pins with ground guard traces, and select load capacitors per the crystal vendor's CL specification (typically 12-22 pF). Avoid routing fast USART or PWM lines directly beneath the crystal. When using TOSC1/TOSC2 with a 32.768 kHz crystal for the asynchronous timer, keep these traces equally short and isolated - long watch-crystal traces pick up digital noise and cause timekeeping drift.
Compliance Information
RoHS compliant green package per distributor listings. AEC-Q100 automotive qualification not applicable to this commercial/industrial grade part. REACH and conflict mineral status not stated in provided data.
