ATMEGA165PA-MNR - 8-bit AVR MCU, 16KB Flash, 16MHz | Microchip
MPN: ATMEGA165PA-MNR β Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
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| 500 | $0 | $0.00 |
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ATMEGA165PA-MNR Overview
A microcontroller unit (MCU) is a single integrated circuit that combines a processor core, program memory, data memory, and peripherals such as timers, UARTs, ADCs, and SPI/I2C interfaces. Within the power-management hierarchy of embedded systems, an MCU sits between discrete logic and application processors, providing complete embedded control in one chip. The ATmega165PA belongs to the AVR ATmega family of 8-bit RISC MCUs, a widely deployed architecture in industrial control, consumer, and instrumentation products.
Key features include the Advanced RISC architecture with 133 mostly single-cycle instructions and 32 general-purpose working registers, in-system programmable (ISP) flash with read-while-write support, and the picoPower technology that delivers low active and sleep-mode consumption for battery-operated designs. The device also integrates a 10-bit ADC, JTAG interface for on-chip debugging and boundary scan, and multiple USART/SPI/TWI serial channels.
Architecturally, the ATmega165PA uses a Harvard-structure 8-bit AVR core with single-level pipelining, so most instructions execute in one clock cycle and the core achieves close to 1 MIPS per MHz. The PA suffix denotes the picoPower silicon revision, which Microchip documents as a functionally identical drop-in replacement for the earlier ATmega165P, qualified through the same production test flow.
Typical applications include industrial automation and sensor nodes, battery-powered portable instruments, LED and LCD-based HMI panels, and automotive-adjacent control boards where a 16 MHz, 16 KB flash budget is sufficient.
When designing with this device, plan the clocking strategy early: the 16 MHz maximum rating applies with a stable supply of 4.5 V to 5.5 V, while lower-voltage operation requires reduced clock frequencies, so verify the frequency-versus-voltage curve in the Microchip datasheet before committing to a 3.3 V system clock.
This page synthesizes verified distributor listings, drop-in alternatives, pin-compatibility guidance, and practical design notes that are not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA165PA-MNR 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 ATMEGA165PA-MNR (same form factor and footprint) β differing in EEPROM, Flash Memory, Instruction Set, Package, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA325PA-MNR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA645P-MNR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA169PA-MN
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA169P-15MT
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA649P-MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA165PA-MNR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed (Max Clock) | 16 MHz |
| Flash Memory | 16 KB (8K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Number of I/O | 54 |
| General Purpose Working Registers | 32 |
| Instruction Set | 133 instructions, most single-cycle |
| Performance | Up to 16 MIPS at 16 MHz |
| Package | 64-VFQFN Exposed Pad (9x9 mm) |
| Mounting Type | Surface Mount |
| Flash Programming | ISP with read-while-write |
| Low Power Technology | picoPower |
| Debug Interface | JTAG / ICSP (2 device I/O pins + reset) |
| Lifecycle Status | ACTIVE |
ATMEGA165PA-MNR 64-vfqfn exposed pad (9x9 mm) Pin Configuration Guide
Pin configuration for ATMEGA165PA-MNR (64-vfqfn exposed pad (9x9 mm) 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 ATMEGA165PA-MNR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA165PA-MNR is suitable for 6 applications: Industrial Automation and Control, Battery-Powered Portable Instruments, LCD Human-Machine Interface Panels, Sensor Nodes and IoT Edge Devices, Motor and Actuator Control, Test and Measurement Instrumentation.
Industrial Automation and Control
In factory automation nodes, the ATMEGA165PA-MNR provides 16 KB of ISP flash and 54 GPIO, enough to drive relays, read limit switches, and bit-bang or hardware-link Modbus-style UART protocols without an external expander. Its 16 MHz AVR core executes roughly 16 MIPS, which is sufficient for deterministic scan loops in the 1-10 ms range typical of machine I/O modules. The JTAG interface allows boundary-scan production test and in-circuit debugging on densely populated control boards, reducing field bring-up time. Because the flash supports read-while-write, an application can log parameters to EEPROM/flash while running the control loop. Supply tolerance from 1.8 V to 5.5 V lets the same firmware image span 3.3 V logic boards and 5 V industrial sensors, provided the clock-frequency-versus-voltage limits in the Microchip datasheet are respected.
Recommended
Battery-Powered Portable Instruments
The picoPower silicon of the ATmega165PA is specifically targeted at battery-operated designs. With a 1.8 V minimum supply, two-cell alkaline or NiMH stacks power the device directly, and multiple sleep modes allow the MCU to idle between measurements in hand-held meters and data loggers. The 10-bit ADC channels handle sensor front ends such as thermistors and strain-gauge bridges, while the 512 B EEPROM retains calibration constants across battery changes. The 64-VFQFN exposed pad simplifies thermal design in sealed enclosures where convection is poor. Firmware can exploit read-while-write flash to log data without halting the acquisition loop. Designers should budget wake-up latency from the selected sleep mode, since deep-sleep modes trade startup time against average current, a trade-off documented in the ATmega165PA datasheet sleep-mode tables.
Recommended
LCD Human-Machine Interface Panels
Front-panel controllers benefit from the ATMEGA165PA-MNR combination of 54 I/O lines and 16 MHz throughput: enough pins to drive a multiplexed segment LCD or a parallel character-LCD bus while simultaneously scanning a keypad matrix and managing backlight PWM. The AVR core executes key-scan debounce and display refresh in deterministic single-cycle instructions, avoiding the timing jitter of software-scheduled approaches. If an integrated segment LCD driver is preferred over GPIO multiplexing, the pin-compatible ATMEGA169PA-MN or ATMEGA649P-MU in the same 64-VFQFN footprint adds the LCD controller, per the Atmel-8285 family datasheet, enabling a board spin with no footprint change. TWI and SPI ports interface touch controllers or rotary encoders for richer panel interaction.
Recommended
Sensor Nodes and IoT Edge Devices
For wired or low-rate wireless sensor nodes, the ATMEGA165PA-MNR integrates USART, SPI, and TWI interfaces to connect RF modules, MEMS sensors, and external EEPROM within one chip. The 1 KB SRAM accommodates packet buffers for typical sub-GHz or 802.15.4 radio stacks at modest data rates, and the 16 KB ISP flash with read-while-write allows field firmware update routines to execute from flash while writing application pages. The picoPower feature set reduces average node current in duty-cycled operation. Supply operation down to 1.8 V matches Li-SOCl2 cell stacks common in long-life metering nodes. Engineers should verify peak clock versus the supply rail from the datasheet frequency-voltage curve, and reserve the JTAG pins if production boundary-scan test coverage is required.
Recommended
Motor and Actuator Control
The ATmega165PA timer suite supports PWM generation suitable for DC motor drive, servo actuation, and heater control. At 16 MHz, 8-bit PWM resolution yields about 62.5 kHz carrier frequencies, high enough for inaudible motor control, while 16-bit timers support servo pulse-position outputs with microsecond accuracy. The 54 GPIO count allows direct drive of H-bridge control logic plus limit-switch and encoder inputs on one MCU. The exposed-pad 64-VFQFN package sinks switching-related die heat into the PCB copper, aiding reliability in enclosed actuators. For inductive kick-back protection, pair the MCU with external gate drivers or protected low-side switches, since the ATmega I/O pins are logic-level outputs and must not sink motor coil current directly.
Recommended
Test and Measurement Instrumentation
Bench accessories such as calibrators, probe interfaces, and panel meters use the ATMEGA165PA-MNR for its combination of a 10-bit ADC, deterministic timers, and JTAG-testable production boards. The 16 MHz core handles UI scanning, communication (USB-UART bridge or RS-232), and measurement scheduling concurrently. EEPROM storage retains calibration coefficients, and ISP flash enables firmware-field updates via a bootloader without removing the device from the board, valuable for calibrated instruments. The 1.8 V to 5.5 V supply range supports both portable 3 V instruments and 5 V rack modules with one firmware baseline. When sub-LSB analog accuracy matters, use an external precision ADC over TWI/SPI and keep the ATmega for digital supervision, since the internal 10-bit ADC is adequate but not metrology-grade.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA165PA-MNR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA325PA-MNR | ATMEGA645P-MNR | ATMEGA169PA-MN | ATMEGA169P-15MT | ATMEGA649P-MU |
|---|---|---|---|---|---|---|
| Package | 64-VFQFN (9x9) Exposed Pad | 64-VFQFN (9x9) - same | 64-VFQFN (9x9) - same | 64-VFQFN - same | 64-QFN - same footprint | 64-VQFN - same footprint |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Speed | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz | AVR 8-bit, 16 MHz |
| Flash Memory | 16 KB (8K x 16) | 32 KB | 64 KB | 16 KB | 16 KB | 64 KB |
| SRAM | 1 KB | 2 KB | 4 KB | 1 KB | 1 KB | 4 KB |
| EEPROM | 512 B | 1 KB | 2 KB | 512 B | 512 B | 2 KB |
| Integrated LCD Driver | No | No | No | Yes (segment LCD) | Yes (segment LCD) | Yes (segment LCD) |
| Low-Power Silicon | picoPower (PA) | picoPower (PA) | P (non-picoPower) | picoPower (PA) | P (non-picoPower) | P (non-picoPower) |
Key Differentiators
- picoPower silicon at the same 16 KB budget (vs ATMEGA645P-MNR)
- JTAG debug/boundary-scan on a 64-pin footprint (vs ATMEGA164PA-MNR)
- Lowest-cost 16 KB option vs LCD-driver siblings (vs ATMEGA169PA-MN)
Design Notes
The 16 MHz maximum clock is only valid across the full 4.5 V to 5.5 V supply per the AVR safe-operating frequency-versus-voltage curve in the ATmega165PA datasheet. A 3.3 V system must derate the clock (ATmega AVR devices typically permit roughly 8 MHz at 3.3 V; confirm the exact curve in Atmel doc 8285 before committing). Exceeding the curve causes marginal flash read timing and sporadic crashes that only appear over temperature. If you need 16 MHz at 3.3 V, select a 3V-tolerant member such as ATMEGA128L family parts instead.
The 64-VFQFN exposed pad is the primary ground return; connect it to a solid ground plane with an array of thermal vias (typically 5x5, 0.3 mm drill) under the pad. Insufficient via arrays cause floating-ground behavior that appears as JTAG communication failures rather than obvious power faults. Decouple each VCC pin pair (pins 9/10 and 35/36 regions) with 100 nF ceramics placed within 2 mm of the pin, plus 10 uF bulk at the regulator. Verify paste stencil segmentation on the exposed pad to avoid voiding during reflow.
JTAG pins (on the port-F multiplex in this family) double as ADC inputs; if boundary scan is not needed, disable JTAGEN via fuse to recover those pins as GPIO, but note the disable only takes effect through fuse programming, not runtime software. Keep SPI clock lines short and series-terminate above 8 MHz operation to reduce ringing on the 9x9 QFN's short leads. Route the XTAL pair as a tight differential with a guard ground; external crystal load capacitors must match the datasheet CL specification for start-up reliability across temperature.
When migrating a board from ATmega165P to ATmega165PA, AVR529 confirms functional identity, but order-code confusion is the real risk: -MNR (VFQFN) and -AN/-AU (TQFP) are not footprint-compatible, so verify the package code on PO lines. Also, the PA silicon reads a different device signature than the 165P, so production programmers with a locked signature check will reject the swap until the signature database is updated. Update both the programming tool firmware and fixture expectations before the first PA build.
Compliance Information
Compliance attributes were not stated in the verified data captured for this page; confirm RoHS/REACH status on the Microchip product page or distributor compliance documentation before production.
