ATMEGA164P-20MU - 8-bit AVR MCU 20MHz 16KB Flash | Microchip
MPN: ATMEGA164P-20MU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.62 | $4.62 |
| 10 | $4.18 | $41.80 |
| 100 | $3.71 | $371.00 |
| 500 | $3.35 | $1,675.00 |
| 1,000 | $2.98 | $2,980.00 |
ATMEGA164P-20MU Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most instructions in a single clock cycle. Within the power management and embedded control hierarchy, MCUs like the ATmega164P sit at the heart of embedded systems, combining program memory, SRAM, EEPROM, timers, and communication peripherals on a single die. Microchip (formerly Atmel) AVR devices are programmed through ISP (In-System Programming) and supported by the AVR GCC toolchain and Atmel Studio / Microchip Studio IDE.
Key features include 16KB self-programmable FLASH with read-while-write support, 512B EEPROM, 1KB SRAM, 32 general purpose I/O lines, and 32 general purpose working registers. The picoPower technology delivers low-power sleep modes (idle, power-down, power-save) suitable for battery-operated products.
Technically, the device integrates a two-cycle on-chip multiplier, three flexible 8/16-bit timer/counters with compare modes and PWM, a real-time counter (RTC) with separate oscillator, two USARTs, a byte-oriented Two-Wire Interface (TWI/I2C), an SPI serial port, and an 8-channel 10-bit ADC. The enhanced RISC core implements 133 powerful instructions, most single-cycle, achieving up to 20 MIPS throughput at 20MHz.
Typical applications include industrial control and automation nodes, consumer appliances, sensor and battery-powered data loggers, and embedded communication interfaces such as RS-485 gateways using the dual USARTs. The 44-VQFN (7x7) footprint suits compact two-layer and four-layer PCBs.
When designing with the ATMEGA164P-20MU, decouple VCC with 0.1uF ceramics at each supply pin and keep the exposed pad soldered to a ground pour for thermal and signal integrity. Note that Microchip recommends the newer ATMEGA164PA for new designs.
This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, with data verified as of 2026-09-16.
Drop-in alternatives for ATMEGA164P-20MU 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 ATMEGA164P-20MU (same form factor and footprint) β differing in Package, ADC, Flash Memory, Instructions, Serial Interfaces.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA164PA-MU
β Drop-Inβ In Stock
$2.55 / Unit
View Datasheet βATMEGA164A-MU
β Drop-Inβ In Stock
$3.01 / Unit
View Datasheet βATMEGA324P-20MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA644P-20MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA1284P-MUR
β Drop-Inβ In Stock
Contact for price
View Datasheet βATMEGA164P-20MU Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 20 MHz |
| Program Memory Size | 16 KB (8K x 16) FLASH |
| EEPROM Size | 512 B |
| RAM Size | 1 KB SRAM |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O | 32 |
| Timers/Counters | 3 (with compare modes and PWM) |
| Communication Interfaces | 2x USART, TWI (I2C), SPI |
| ADC | 8-channel 10-bit |
| RTC | Yes (real-time counter) |
| Instructions | 133 (advanced RISC, mostly single-cycle) |
| Package | 44-VQFN (7x7 mm) with Exposed Pad |
| Mounting Type | Surface Mount |
| Low Power Technology | picoPower |
| Programming | ISP (In-System Programming), read-while-write |
ATMEGA164P-20MU 44-vqfn (7x7 mm) with exposed pad Pin Configuration Guide
Pin configuration for ATMEGA164P-20MU (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 ATMEGA164P-20MU.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA164P-20MU is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Data Loggers, Embedded Communication Gateways, Consumer Appliance Control, Sensor Acquisition Modules, Hobby, Education, and Prototyping.
Industrial Control and Automation
The ATMEGA164P-20MU fits industrial control nodes because its 20MHz AVR core delivers roughly 20 MIPS throughput, while its two USARTs, SPI, and TWI interfaces connect PLC-style I/O, RS-485 fieldbuses, and HMI panels. The 8-channel 10-bit ADC digitizes analog sensor inputs such as potentiometers, current shunts, and temperature signals directly, and three timer/counters with PWM drive motor drivers or actuators. Operating from 2.7V to 5.5V, the part tolerates industrial 5V rails, and the 44-VQFN (7x7) package keeps controller boards compact. The 16KB flash with read-while-write support permits in-field firmware updates over the existing serial link, reducing maintenance cost in deployed equipment.
Recommended
Battery-Powered Data Loggers
For battery-powered data loggers, the ATMEGA164P-20MU combines picoPower sleep modes with a real-time counter clocked from a separate 32kHz crystal, allowing the MCU to wake on a schedule in power-save mode while keeping most of the die unpowered. The 2.7V to 5.5V supply range accepts lithium cells directly without a regulator, and the 512B EEPROM stores calibration constants and logs across power cycles. The 10-bit ADC samples analog sensors on eight channels, and flash read-while-write enables logging into program memory pages. Engineers targeting the lowest possible power-down current should evaluate the ATMEGA164PA-MU, which improves picoPower sleep performance while sharing the same 44-VQFN footprint and codebase.
Recommended
Embedded Communication Gateways
The dual USART architecture makes the ATMEGA164P-20MU well suited to protocol-conversion gateways, for example bridging an RS-232 debug console to an RS-485 Modbus RTU fieldbus. Each USART provides 5- to 9-bit framing with programmable baud generation from the 20MHz clock, and hardware parity and framing error flags simplify robust link management. The TWI (I2C) and SPI masters extend the gateway to I2C sensors or SPI-based transceivers, while the 16KB flash accommodates two protocol stacks with headroom at 20 MIPS execution speed. The 44-VQFN (7x7) exposed-pad package gives low-inductance grounding for clean signal integrity on long wired networks.
Recommended
Consumer Appliance Control
In consumer appliances such as coffee machines, climate controllers, and small pumps, the ATMEGA164P-20MU provides cost-effective intelligence: a 20MHz core for responsive UI handling, 32 GPIO lines for keypads, LEDs, and relays, and PWM outputs for heater or fan control. The 10-bit ADC reads NTC thermistors and user potentiometers, and the 512B EEPROM persists user settings and usage counters through power loss. The 5V-tolerant 2.7-5.5V range and wide industrial-grade availability simplify mains-powered designs using a simple linear supply. Its availability from 11 distributors, reported by Octopart, supports stable long-term sourcing for high-volume consumer product lines.
Recommended
Sensor Acquisition Modules
The ATMEGA164P-20MU works well as a compact sensor acquisition node: its 8-channel, 10-bit ADC with internal reference converts up to eight analog sensors, and SPI connects external higher-resolution converters such as 16/24-bit delta-sigma ADCs when finer accuracy is required. The TWI interface reads digital sensors (temperature, humidity, accelerometers), while timer capture inputs log event timing. The 44-VQFN (7x7) exposed-pad package suits small module PCBs, and picoPower sleep modes allow duty-cycled sampling that extends battery life in remote monitoring installations. The 1KB SRAM supports modest averaging filters and packet buffering for wireless or wired upstream transmission through a USART.
Recommended
Hobby, Education, and Prototyping
The ATmega164P family is a popular choice for embedded education and prototyping because its AVR RISC core is well documented, supported by free AVR GCC toolchains and Microchip Studio, and programmable with low-cost ISP tools such as the AVRISP mkII or Arduino-as-ISP. The 16KB flash is large enough for structured C programs with UART, I2C, SPI, and ADC demonstrations, while the 44-VQFN (7x7) footprint teaches surface-mount assembly skills. The 32 GPIO and 20 MIPS performance support robotics, LED matrix, and small display projects. Because it is pin-compatible with the ATmega324P/644P, students can scale projects up without changing hardware layout.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164P-20MU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164PA-MU | ATMEGA164A-MU | ATMEGA324P-20MU | ATMEGA644P-20MU | ATMEGA1284P-MUR |
|---|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) with Exposed Pad | 44-VQFN (7x7) - same | 44-VQFN (7x7) - same | 44-VQFN (7x7) - same | 44-VQFN (7x7) - same | 44-VQFN - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| FLASH Memory | 16 KB | 16 KB | 16 KB | 32 KB | 64 KB | 128 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 2 KB | 4 KB | 16 KB |
| EEPROM | 512 B | 512 B | 512 B | 1 KB | 2 KB | 4 KB |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Low-Power Technology | picoPower | picoPower (improved) | standard | picoPower | picoPower | picoPower |
| Lifecycle Status | Active (newer ATMEGA164PA available) | Active - recommended for new designs | Active | Active | Active | Active |
Key Differentiators
- Dual USARTs in a 44-pin footprint (vs ATMEGA168P-20MU)
- Recommended newer-generation upgrade path (vs ATMEGA164PA-MU)
- Scalable memory on an identical footprint (vs ATMEGA644P-20MU)
Design Notes
The 44-VQFN (7x7) package has a center exposed pad that must be soldered to a ground pour, both for mechanical anchoring and for the low-inductance ground reference that reduces ADC noise and EMI. Use a 4x4 or 5x5 via array under the pad to stitch the top ground pour to internal ground planes. Keep the 0.1uF decoupling capacitor for each VCC pin within 2 mm of the pin, and place a 10uF bulk capacitor near the supply entry. Pin 1 identification follows the QFN dot marker; verify against the datasheet pinout diagram before reflow.
With a 2.7V to 5.5V supply range, the -20 speed grade is safe at 20MHz across the range, but verify AVCC connections: AVCC must be tied to VCC through a low-pass LC network (for example 10uH inductor with 0.1uF capacitor) when ADC accuracy matters, and must never be left floating even if the ADC is unused. Estimated: at 5V and 20MHz with typical active current in the low-mA range per the datasheet, a 3.3V/5V LDO rated at 100mA provides ample margin for the MCU plus external sensors.
Migrating between ATmega164P/324P/644P is documented in Microchip application note AVR505 (doc8001), but engineers sometimes overlook EEPROM and fuse default differences between P and A/PA variants - always read and re-verify fuse settings (clock source, BOD level, JTAG/SPI enable) after switching parts, or the board may appear dead. Additionally, if using the RTC, remember it requires an external 32kHz crystal on Timer/Counter2's oscillator pins; a standard main crystal alone will not drive the asynchronous RTC.
Compliance Information
Compliance details were not stated in the provided verified web data; consult the Microchip product page or environmental data sheet for RoHS/REACH status.
