ATMEGA164P-20MUR - 8-Bit AVR MCU 20MHz 16KB Flash | Microchip
MPN: ATMEGA164P-20MUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.78 | $1.78 |
| 10 | $1.72 | $17.20 |
| 100 | $1.65 | $165.00 |
| 500 | $1.58 | $790.00 |
| 1,000 | $1.5 | $1,500.00 |
ATMEGA164P-20MUR Overview
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripherals such as timers and serial interfaces on one die. Within the embedded-systems hierarchy, the ATmega164P sits in Microchip (formerly Atmel) AVR ATmega family of general-purpose 8-bit MCUs, positioned below the ATmega644/1284 and above the ATmega16 in memory density.
Key features include 16 KB of self-programmable ISP Flash with read-while-write support, 512 B EEPROM for nonvolatile parameter storage, 32 general-purpose I/O lines, and two dedicated USARTs for multi-channel serial communication. The 8-channel, 10-bit ADC supports sensor interfacing, while the byte-oriented Two-Wire interface (TWI, I2C-compatible) and SPI enable peripheral expansion. Three flexible timer/counters with compare modes and PWM outputs cover motor control and lighting-dimming tasks.
Technically, the AVR advanced RISC architecture executes 133 powerful instructions, most in a single clock cycle, through a 32-register file directly connected to the ALU. This achieves up to 20 MIPS throughput at 20 MHz. The picoPower technology set provides multiple sleep modes and a real-time counter running from a 32 kHz crystal, cutting standby current dramatically for battery designs.
Typical applications include industrial control panels, HVAC and building automation nodes, consumer appliances, and instrument front ends where two UARTs, ample analog inputs, and 5V tolerance simplify the BOM.
For design, note that full 20 MHz operation requires a 4.5V to 5.5V supply per the AVR speed-grade convention; at 2.7V to 5.5V the safe operating frequency is lower, so verify the supply rail before fixing the crystal frequency.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA164P-20MUR 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-20MUR (same form factor and footprint) β differing in Package, Flash Memory, Serial Interfaces, ADC, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA164PA-MUR
β Drop-Inβ In Stock
$2.89 / Unit
View Datasheet βATMEGA164P-20MU
β Drop-Inβ In Stock
$2.98 / Unit
View Datasheet βATMEGA164A-MU
β Drop-Inβ In Stock
$3.01 / Unit
View Datasheet βATMEGA1284P-MUR
β Drop-Inβ In Stock
Contact for price
View Datasheet βATMEGA644P-20MUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA16-16MUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA162V-8AUR
β Drop-Inβ In Stock
$6.62 / Unit
View Datasheet βATMEGA164P-20MUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 16 KB (8K x 16) ISP Flash with read-while-write |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Instruction Set | 133 instructions, most single-cycle |
| Throughput | Up to 20 MIPS at 20 MHz |
| General Purpose I/O | 32 I/O lines |
| Working Registers | 32 general purpose registers |
| USART | 2 |
| Timers/Counters | 3 (with compare modes and PWM) |
| ADC | 8-channel, 10-bit |
| Serial Interfaces | 2x USART, TWI (I2C-compatible), SPI |
| Real-Time Counter | Yes (32 kHz crystal) |
| Low Power Technology | picoPower with multiple sleep modes |
| Package | 44-VQFN (7x7 mm), exposed pad |
| Mounting Type | Surface Mount |
| Temperature Grade | Industrial (I suffix) |
| Lifecycle Stage | ACTIVE |
ATMEGA164P-20MUR 44-vqfn (7x7 mm), exposed pad Pin Configuration Guide
Pin configuration for ATMEGA164P-20MUR (44-vqfn (7x7 mm), 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-20MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA164P-20MUR is suitable for 6 applications: Industrial Control and Automation Nodes, Building Automation and HVAC Controllers, Serial Gateways and Protocol Converters, Consumer Appliances and White Goods, Battery-Powered Measurement Instruments, LED Lighting and PWM Dimming Control.
Industrial Control and Automation Nodes
The ATMEGA164P-20MUR fits industrial control nodes because its industrial temperature grade, 32 GPIO lines, and 20 MIPS AVR core handle relay sequencing, limit-switch polling, and local closed-loop logic without an external supervisor. The 16 KB ISP Flash with read-while-write lets firmware field-updates over the existing RS-485 link via a bootloader, while 512 B EEPROM stores calibration constants and station addresses across power cycles. The two USARTs are decisive: one port bridges a Modbus RTU network at 9600-115200 baud while the second serves a local HMI or printer. Running at 5V matches legacy industrial signal levels, eliminating level shifters, and picoPower sleep modes cut standby draw in intermittently polled stations.
Recommended
Building Automation and HVAC Controllers
HVAC zone controllers benefit directly from the ATMEGA164P-20MUR combination of an 8-channel, 10-bit ADC and picoPower sleep architecture. Up to eight temperature, humidity, and pressure sensors connect through the analog mux without an external ADC, and the onboard 2.56V reference plus 10-bit resolution yields roughly 2.5 mV LSB, adequate for NTC thermistor chains. The real-time counter running from a 32 kHz crystal keeps schedules alive in power-save sleep between sampling windows, extending battery-backed operation. Three timers generate PWM for damper actuators and fan speed control, while TWI manages display and EEPROM expansion. The 44-VQFN 7x7 mm footprint fits compact thermostat PCBs with two-layer routing.
Recommended
Serial Gateways and Protocol Converters
With two independent USARTs, the ATMEGA164P-20MUR is a natural fit for protocol converters bridging RS-232, RS-485, and UART-based field devices. A typical gateway uses USART0 as a Modbus RTU slave on RS-485 and USART1 as a device-side UART, buffering frames in the 1 KB SRAM. At 20 MHz the single-cycle RISC core sustains tens of thousands of interrupt-driven byte transfers per second with headroom for CRC16 computation. The 16 KB Flash hosts dual protocol stacks plus a bootloader for remote firmware upgrades over the network side. XAIPART recommends enabling RX-complete interrupts with ring buffers and verifying 5V logic compatibility with RS-485 transceivers such as standard 5V parts.
Recommended
Consumer Appliances and White Goods
Appliance control boards - coffee machines, rice cookers, vacuum units - use the ATMEGA164P-20MUR because it integrates everything a cost-driven appliance BOM needs: 32 GPIO for keys, LEDs, and relay drives; an ADC for NTC temperature sensing and mains zero-cross detection; and TWI for capacitive-touch expansion controllers. PicoPower sleep modes keep standby power low enough to meet energy-standby regulations, waking on interrupt from a touch encoder. The 44-VQFN 7x7 exposed-pad package provides low thermal resistance to the PCB and good vibration tolerance versus through-hole parts. The 512 B EEPROM retains user preferences and error logs through power failures without external NVM.
Recommended
Battery-Powered Measurement Instruments
Handheld meters and loggers choose the ATMEGA164P-20MUR for its picoPower power-down and power-save modes paired with the RTC on a 32 kHz crystal: the MCU sleeps between samples and wakes on a timer or comparator event, dramatically extending battery life versus always-running designs. The 8-channel 10-bit ADC multiplexes voltage, current-shunt, and sensor inputs; the 1 KB SRAM holds a sample burst before a burst write to EEPROM or upload over USART. Running from 2x AA cells at roughly 3V, select a crystal frequency within the low-voltage speed derating rather than the full 20 MHz, which requires 4.5V or higher per the AVR speed-grade curve.
Recommended
LED Lighting and PWM Dimming Control
The three timer/counters with compare modes and PWM outputs let the ATMEGA164P-20MUR drive multi-channel LED dimming directly: two high-resolution PWM channels handle warm/white color mixing while a third controls fan speed for thermal management, all hardware-timed so brightness is jitter-free. The ADC reads a potentiometer or 0-10V dimming input, and TWI supports addressable driver expansion. The 5V-tolerant GPIO sinks and sources enough current for MOSFET gate drive through a small transistor stage. The 44-VQFN exposed pad conducts gate-driver switching heat to the PCB ground plane, and 20 MHz operation gives resolution headroom for high-frequency PWM above audible noise thresholds.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164P-20MUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164PA-MUR | ATMEGA164P-20MU | ATMEGA164A-MU | ATMEGA1284P-MUR | ATMEGA16-16MUR |
|---|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same | 44-VQFN (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 16 KB | 16 KB | 128 KB | 16 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 16 KB | 1 KB |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 16 MHz |
| USART Count | 2 | 2 | 2 | 2 | 2 | 1 |
| picoPower Low-Power Feature Set | Yes | Yes | Yes | No (standard core) | Yes | No |
| Firmware Migration from ATMEGA164P-20MUR | Baseline | None - functionally identical drop-in (AVR527) | None - identical die | Recompile, sleep-mode registers differ | Recompile, memory map extension only | Porting required (peripheral set differs) |
Key Differentiators
- Functionally identical drop-in successor exists (vs ATMEGA164PA-MUR)
- Two USARTs at 16 KB Flash cost point (vs ATMEGA16-16MUR)
- Memory headroom without footprint change (vs ATMEGA1284P-MUR)
Design Notes
Respect the AVR speed-voltage derating: the -20 speed grade targets 4.5V to 5.5V rails for 20 MHz operation, while the overall supply window is 2.7V to 5.5V. If your board runs at 3.3V, either drop the crystal to a frequency within the datasheet's low-voltage curve or select the appropriate speed-grade ordering code. Decouple each VCC pad pair with 100 nF ceramics placed within 2 mm of the pads, plus a 10 uF bulk capacitor near the regulator; the exposed center pad must be solidly soldered to the ground plane as the main ground return.
The 44-VQFN (7x7 mm) with exposed pad requires an exact-footprint land pattern with via-fenced center pad for solder voiding control. The ATmega164P shares its pinout family with the ATmega164A, ATmega324P/A, and ATmega644P, so laying out the board for the family (not just this MPN) preserves second-source flexibility - Microchip appnote AVR505 documents family migration paths. Keep the RESET trace short and add a 10 kOhm pullup plus optional ISP header with series resistors on MOSI/MISO/SCK to avoid bus contention during programming.
Two frequent integration errors: first, forgetting that the ADC reference and analog supply depend on AVCC - if AVCC is absent or unfiltered, conversions are inaccurate; tie AVCC to VCC through an LC filter and connect AREF with a 100 nF cap. Second, assuming EEPROM survives all brownout conditions: enable the internal brown-out detector fuse so the core halts before VCC falls below the EEPROM write-integrity threshold, preventing corrupted calibration data. Verify fuses (clock source, BOD level, JTAG enable) before releasing production - default fuse settings may select the internal RC oscillator rather than your external crystal.
Compliance Information
RoHS/lead-free status per standard Microchip MUR reel suffix build; REACH, halogen-free, and conflict-minerals statuses not stated in verified data - obtain certificates from Microchip or distributor at order time.
