ATMEGA164P-20AQR - 16KB Flash 20MHz AVR MCU | Microchip
MPN: ATMEGA164P-20AQR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.47 | $1.47 |
| 10 | $1.33 | $13.30 |
| 100 | $1.19 | $119.00 |
| 500 | $1.08 | $540.00 |
| 1,000 | $0.97 | $970.00 |
ATMEGA164P-20AQR Overview
An 8-bit AVR microcontroller is a single-chip processor based on the AVR enhanced RISC architecture, in which most instructions execute in a single clock cycle to deliver throughput close to 1 MIPS per MHz. Within the embedded systems hierarchy it spans microcontroller -> 8-bit MCU -> AVR ATmega family -> picoPower device class, combining CPU, program memory, data memory, and peripherals in one package for cost- and power-sensitive designs.
Key features include read-while-write flash for safe in-application firmware updates, 32 general-purpose I/O lines, 32 general-purpose working registers, and the picoPower low-power CMOS process for aggressive sleep-mode current targets. Peripherals include USARTs, SPI, two-wire interface (I2C-compatible), a 10-bit ADC with 8 channels, timers/PWM, and an on-chip debug/ICSP path compatible with MPLAB SNAP.
Architecturally, the ATmega164P pairs the AVR RISC core with Harvard memory organization, allowing simultaneous program and data access; the datasheet (Atmel-42742) documents in-system programmable flash and the full peripheral register set. The single-cycle execution model lets designers trade clock speed directly against power consumption.
Typical applications include industrial control nodes, consumer appliances, sensor and actuator interfaces, and battery-powered instrumentation where 5V logic compatibility and 20 MIPS headroom are needed.
Design consideration: pin-compatible migration across the ATmega164P/324P/644P family is supported (see Microchip application note AVR505), so flash footprint can be scaled without a PCB change.
This page synthesizes verified distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA164P-20AQR 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-20AQR (same form factor and footprint) β differing in Packaging, Supply Voltage Range, Core Architecture, Package, Throughput.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA164P-20AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164PA-AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.05 / Unit
View Datasheet βATMEGA164A-AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA324P-20AUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164P-15AT
β Drop-Inβ In Stock
$2.35 / Unit
View Datasheet βATMEGA1608-AUR
β Drop-Inβ In Stock
$0.92 / Unit
View Datasheet βATMEGA164P-20AQR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Memory | 16 KB (8K x 16) ISP Flash with read-while-write |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Throughput | Up to 20 MIPS (1 MIPS per MHz) |
| General Purpose I/O | 32 lines |
| Working Registers | 32 general purpose |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (R suffix) |
| Debug / Programming | ICSP via 2 I/O pins + reset; MPLAB SNAP compatible |
| Low Power Technology | picoPower |
| Product Status | Active |
ATMEGA164P-20AQR Pin Configuration
| Pin 1 | PB5 β Port B bit 5 / T1 timer input |
| Pin 2 | PB6 β Port B bit 6 / T2 timer input |
| Pin 3 | PB7 β Port B bit 7 / OC0A / XTAL2 alternate |
| Pin 4 | RESET β Active-low reset input (also ICSP) |
| Pin 5 | VCC β Digital supply voltage |
| Pin 6 | GND β Digital ground |
| Pin 7 | XTAL2 β Crystal oscillator output |
| Pin 8 | XTAL1 β Crystal oscillator input / external clock |
| Pin 9 | PD0 β Port D bit 0 / RXD0 (USART0 receive) |
| Pin 10 | PD1 β Port D bit 1 / TXD0 (USART0 transmit) |
| Pin 11 | PD2 β Port D bit 2 / INT0 external interrupt |
| Pin 12 | PD3 β Port D bit 3 / INT1 external interrupt |
| Pin 13 | PD4 β Port D bit 4 / XCK0 / T0 |
| Pin 14 | VCC β Digital supply voltage |
| Pin 15 | GND β Digital ground |
| Pin 16 | PD5 β Port D bit 5 / XCK1 / OC1A |
| Pin 17 | PD6 β Port D bit 6 / ICP1 input capture |
| Pin 18 | PD7 β Port D bit 7 / OC2A / OC1B |
| Pin 19 | PC0 β Port C bit 0 / SCL (two-wire interface clock) |
| Pin 20 | PC1 β Port C bit 1 / SDA (two-wire interface data) |
| Pin 21 | PC2 β Port C bit 2 / TCK (JTAG test clock) |
| Pin 22 | PC3 β Port C bit 3 / TMS (JTAG test mode select) |
| Pin 23 | PC4 β Port C bit 4 / TDO (JTAG test data out) |
| Pin 24 | PC5 β Port C bit 5 / TDI (JTAG test data in) |
| Pin 25 | PC6 β Port C bit 6 / TOSC1 (RTC oscillator in) |
| Pin 26 | PC7 β Port C bit 7 / TOSC2 (RTC oscillator out) |
| Pin 27 | AVCC β Analog supply for ADC (connect to VCC via filter) |
| Pin 28 | GND β Analog ground |
| Pin 29 | AREF β ADC analog reference input |
| Pin 30 | PA7 β Port A bit 7 / ADC7 analog input |
| Pin 31 | PA6 β Port A bit 6 / ADC6 analog input |
| Pin 32 | PA5 β Port A bit 5 / ADC5 analog input |
| Pin 33 | PA4 β Port A bit 4 / ADC4 analog input |
| Pin 34 | PA3 β Port A bit 3 / ADC3 analog input |
| Pin 35 | PA2 β Port A bit 2 / ADC2 analog input |
| Pin 36 | PA1 β Port A bit 1 / ADC1 analog input |
| Pin 37 | PA0 β Port A bit 0 / ADC0 analog input |
| Pin 38 | PB0 β Port B bit 0 / SS (SPI slave select) |
| Pin 39 | PB1 β Port B bit 1 / SCK (SPI clock) |
| Pin 40 | PB2 β Port B bit 2 / MOSI (SPI data out) |
| Pin 41 | PB3 β Port B bit 3 / MISO (SPI data in) |
| Pin 42 | PB4 β Port B bit 4 / OC0 PWM output |
| Pin 43 | VCC β Digital supply voltage |
| Pin 44 | GND β Digital ground |
Typical Applications
ATMEGA164P-20AQR is suitable for 6 applications: Industrial Control Nodes, Battery-Powered Instrumentation, Consumer Appliances, Sensor and Actuator Interfaces, Embedded Debug and Education Boards, Motor Control and PWM Systems.
Industrial Control Nodes
The ATMEGA164P-20AQR fits industrial control nodes because its 32 GPIO lines, 20 MHz throughput (up to 20 MIPS), and 5.5V tolerant supply let it directly interface relays, optocouplers, and 5V logic without level shifting. Its two USARTs and SPI allow robust RS-485 or Modbus connectivity via an external transceiver. Using picoPower sleep modes between polling cycles reduces board-level power, and the read-while-write flash supports field firmware updates over the bus. Place the MCU between the transceiver and I/O driver stages with 100 nF decoupling per VCC pin; the trade-off versus a 32-bit MCU is fewer MIPS but far lower complexity and BOM cost.
Recommended
Battery-Powered Instrumentation
For battery-powered meters and portable instruments, the ATMEGA164P's picoPower CMOS technology minimizes current draw in idle and power-down modes, while the 1 MIPS-per-MHz architecture lets designers clock the part at just 1-4 MHz and still meet response deadlines, cutting active current proportionally. The 10-bit ADC with 8 channels handles sensor inputs directly, and the 512 B EEPROM stores calibration constants without external memory. Running from 2.7V allows two-cell alkaline or single Li-ion operation. Use the internal RC oscillator at low speeds and reserve the 20 MHz crystal for measurement bursts; this hybrid clocking strategy is the primary power-optimization lever on this device.
Recommended
Consumer Appliances
Home appliances such as coffee machines, fans, and small heating controllers benefit from the ATMEGA164P-20AQR's combination of 32 GPIO, timer/PWM resources, and 5V I/O for driving TRIAC triggers, buttons, and 7-segment displays. The 16 KB flash accommodates button-debounce state machines, display multiplexing, and safety interlock logic with headroom for OTA-style field updates via read-while-write flash programming. Its commercial temperature grade matches typical indoor appliance environments. PWM outputs from the on-chip timers directly control motor speed or heater duty cycles without external controllers. The AQR tape-and-reel suffix supports automated SMT lines in volume production, keeping per-unit cost near the $1.47 single-unit level.
Recommended
Sensor and Actuator Interfaces
The ATMEGA164P-20AQR serves as an intelligent sensor hub: its 8-channel 10-bit ADC digitizes analog sensors such as thermistors and potentiometers, while the two-wire interface (I2C-compatible) and SPI connect digital sensors like accelerometers or RTCs. Outputs drive actuators through PWM-capable timer pins, and two USARTs bridge to host systems. The 1 KB SRAM buffers sample arrays for local filtering, and EEPROM stores thresholds and compensation tables. Scanning the ADC with the internal reference and sleeping between samples keeps average current low in picoPower silicon. Design caution: keep analog sensor traces away from the SPI/USART clock lines to preserve the ADC's effective resolution.
Recommended
Embedded Debug and Education Boards
Because the ATmega164P supports in-circuit debugging and ICSP through only two I/O pins plus reset via MPLAB SNAP, it is well suited to evaluation boards, university labs, and hobbyist kits. The classic AVR architecture, free toolchains, and 408-page datasheet (Atmel-42742) provide a gentle learning curve, while the 16 KB flash and 20 MHz clock leave room for meaningful student projects such as UART terminals, ADC oscilloscope demos, and SPI experiments. The 44-TQFP package exposes all 32 I/O lines for breadboard adapters. Boards should route a standard 6-pin ISP header and include a socketed or easily replaced MCU to tolerate beginner wiring mistakes.
Recommended
Motor Control and PWM Systems
The ATMEGA164P-20AQR's multiple timer/PWM channels make it effective for small motor control: DC motor speed, servo positioning, and stepper sequencing can be generated on hardware PWM outputs, offloading the CPU for communication and safety logic. The 20 MHz clock gives 8-bit PWM resolution at high carrier frequencies for quiet motor operation, and the interrupt structure handles quadrature encoder inputs on INT0/INT1 pins. Its 5.5V supply ceiling aligns with gate-driver logic levels for external MOSFET bridges. Compare against a dedicated motor-driver MCU: for single-motor 5V systems the AVR's cost and simplicity win, while multi-axis field-oriented control requires a more powerful part.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA164P-20AQR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA164P-20AUR | ATMEGA164PA-AUR | ATMEGA324P-20AUR | ATMEGA164P-15AT |
|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 16 KB | 32 KB | 16 KB |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 15 MHz |
| EEPROM | 512 B | 512 B | 512 B | 1 KB | 512 B |
| SRAM | 1 KB | 1 KB | 1 KB | 2 KB | 1 KB |
| Low Power Technology | picoPower | picoPower | picoPower (PA revision, lower current) | picoPower | picoPower |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
Key Differentiators
- picoPower silicon for lowest standby current (vs ATMEGA164A-AUR)
- Full 20 MHz speed grade (vs ATMEGA164P-15AT)
- Field-upgradable memory architecture (vs ATMEGA324P-20AUR)
- Extended supply range in PA variant (vs ATMEGA164PA-AUR)
Design Notes
Decouple all three VCC pins and the AVCC pin with 100 nF ceramic capacitors placed within 5 mm of each pin, plus one 10 uF bulk capacitor near the supply entry. Connect AVCC to VCC through an LC filter (10 uH + 100 nF) when ADC accuracy matters, and tie AREF to ground through 100 nF when using the internal reference. The 44-TQFP exposed copper is not an exposed pad, so a solid ground plane on layer 2 provides the return path.
Do not exceed 20 MHz when VCC is below 4.5V; per the AVR speed-grade convention, full-speed 20 MHz operation requires the upper part of the 2.7V-5.5V range. Also, the AQR suffix is the commercial temperature grade - using it outdoors in industrial extremes invites field failures; select the AUR variant instead. During ICSP, keep reset pulled low before applying the programmer or the running firmware may reconfigure the ISP pins.
Exploit picoPower sleep modes to cut average current: estimated power calculation - at 5V and roughly 5 mA active at 20 MHz (typical-class figure; verify exact value in datasheet Table 'Current Consumption'), duty-cycling with 99% power-down operation reduces average current to near the sleep-mode value. Label: this estimate uses nominal supply and duty cycle as inputs; consult the datasheet electrical characteristics table for exact per-mode currents before finalizing battery sizing.
Keep the crystal within 10 mm of XTAL1/XTAL2 with short direct traces and guard with ground pour. Route the two-wire interface (PC0/PC1) with 4.7k pull-ups and keep it away from the SPI clock (PB1) to avoid crosstalk-induced NACKs. For migration headroom, follow AVR505 (Microchip application note doc8001) footprint conventions so ATmega324P or ATmega644P can replace this part without layout change.
Compliance Information
The Q package suffix in Microchip part numbering denotes RoHS-compliant green packaging; detailed REACH and conflict-minerals declarations were not present in the retrieved web data.
