ATMEGA165PA-AU - 8-bit AVR MCU 16MHz 16KB Flash | Microchip
MPN: ATMEGA165PA-AU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.2 | $3.20 |
| 10 | $2.88 | $28.80 |
| 100 | $2.55 | $255.00 |
| 500 | $2.3 | $1,150.00 |
| 1,000 | $2.05 | $2,050.00 |
ATMEGA165PA-AU Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals, serving as the embedded computing heart of a system. The AVR ATmega family sits within the broader hierarchy of 8-bit microcontrollers, which remain widely used for cost-sensitive, real-time control tasks where 32-bit processors are unnecessary overhead. The AVR architecture executes most of its 133 powerful instructions in a single clock cycle, with 32 general-purpose working registers directly connected to the ALU, delivering throughput up to ten times faster than conventional CISC microcontrollers at equivalent clock rates.
Key features include the picoPower technology for ultra-low sleep-mode consumption, a JTAG interface for boundary-scan and on-chip debugging, three flexible 16/8-bit timers, a 10-bit ADC, SPI and USART serial interfaces, and read-while-write Flash for safe self-programming. The -AU suffix denotes the industrial-grade TQFP package with -40C to +85C operation.
Technically, the picoPower P-variant of the ATmega165 family adds an enhanced sleep controller supporting idle, ADC noise reduction, power-save, power-down, standby, and extended standby modes, allowing battery-powered designs to spend most of their life in microamp-level sleep states while waking on pin-change, timer, or watchdog interrupts.
Typical applications include industrial automation controllers, battery-powered metering and sensor nodes, consumer appliance control panels, and motor control systems where a rich peripheral set, 5V tolerance, and mature tooling matter more than raw processing power.
A key design consideration is clock selection: 16MHz full-speed operation requires a 4.5V to 5.5V supply, while 8MHz operation is safe down to 2.7V, so battery designs must scale frequency with voltage per the AVR frequency-voltage curve.
This page synthesizes distributor pricing context, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA165PA-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 ATMEGA165PA-AU (same form factor and footprint) β differing in Operating Temperature, Core Processor, Package, ADC Resolution, Flash Memory.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA165A-AU
β Drop-Inβ In Stock
$3.47 / Unit
View Datasheet βATMEGA165P-16ANR
β Drop-Inβ In Stock
$2.18 / Unit
View Datasheet βATMEGA325A-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA325PA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA169A-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA169PA-AUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA165PA-AU Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Max Clock Speed | 16 MHz |
| Flash Memory | 16 KB (8K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| GPIO Count | 53 |
| Package | 64-TQFP (14x14 mm) |
| Operating Temperature | -40C to +85C |
| Connectivity | SPI, UART/USART, JTAG |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT, picoPower |
| Timers | Two 8-bit, one 16-bit |
| ADC Resolution | 10-bit |
| Instruction Set | 133 instructions, most single-cycle |
| Working Registers | 32 general purpose |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATMEGA165PA-AU Pin Configuration
| Pin 1 | PA7 β Port A bit 7 (AD7, external memory address/data bus) |
| Pin 2 | PA6 β Port A bit 6 (AD6) |
| Pin 3 | PA5 β Port A bit 5 (AD5) |
| Pin 4 | PA4 β Port A bit 4 (AD4) |
| Pin 5 | PA3 β Port A bit 3 (AD3) |
| Pin 6 | PA2 β Port A bit 2 (AD2) |
| Pin 7 | PA1 β Port A bit 1 (AD1) |
| Pin 8 | PA0 β Port A bit 0 (AD0) |
| Pin 9 | VCC β Digital supply voltage |
| Pin 10 | GND β Ground |
| Pin 11 | PC7 β Port C bit 7 (A15 address line) |
| Pin 12 | PC6 β Port C bit 6 (A14) |
| Pin 13 | PC5 β Port C bit 5 (A13) |
| Pin 14 | PC4 β Port C bit 4 (A12) |
| Pin 15 | PC3 β Port C bit 3 (A11) |
| Pin 16 | PC2 β Port C bit 2 (A10) |
| Pin 17 | PC1 β Port C bit 1 (A9) |
| Pin 18 | PC0 β Port C bit 0 (A8) |
| Pin 19 | PG4 β Port G bit 4 (TOSC1, Timer oscillator) |
| Pin 20 | PG3 β Port G bit 3 (TOSC2, Timer oscillator) |
| Pin 21 | VCC β Digital supply voltage |
| Pin 22 | GND β Ground |
| Pin 23 | PE0 β Port E bit 0 (RXD0, UART receive) |
| Pin 24 | PE1 β Port E bit 1 (TXD0, UART transmit) |
| Pin 25 | PE2 β Port E bit 2 (XCK0, USART clock) |
| Pin 26 | PE3 β Port E bit 3 (OC3A, Timer3 PWM output A) |
| Pin 27 | PE4 β Port E bit 4 (OC3B, Timer3 PWM output B) |
| Pin 28 | PE5 β Port E bit 5 (OC3C, Timer3 PWM output C) |
| Pin 29 | PE6 β Port E bit 6 (T3, Timer3 external clock) |
| Pin 30 | PE7 β Port E bit 7 (ICP3, Timer3 input capture) |
| Pin 31 | GND β Ground |
| Pin 32 | VCC β Digital supply voltage |
| Pin 33 | PF0 β Port F bit 0 (ADC0, analog input) |
| Pin 34 | PF1 β Port F bit 1 (ADC1) |
| Pin 35 | PF2 β Port F bit 2 (ADC2) |
| Pin 36 | PF3 β Port F bit 3 (ADC3) |
| Pin 37 | PF4 β Port F bit 4 (TCK/ADC4, JTAG test clock) |
| Pin 38 | PF5 β Port F bit 5 (TMS/ADC5, JTAG test mode select) |
| Pin 39 | PF6 β Port F bit 6 (TDO/ADC6, JTAG test data out) |
| Pin 40 | PF7 β Port F bit 7 (TDI/ADC7, JTAG test data in) |
| Pin 41 | AVCC β Analog supply voltage for ADC and port F |
| Pin 42 | GND β Ground |
| Pin 43 | PD0 β Port D bit 0 (SCL/INT0, TWI clock / external interrupt 0) |
| Pin 44 | PD1 β Port D bit 1 (SDA/INT1, TWI data / external interrupt 1) |
| Pin 45 | PD2 β Port D bit 2 (RXD1/INT2, UART1 receive / external interrupt 2) |
| Pin 46 | PD3 β Port D bit 3 (TXD1/INT3, UART1 transmit / external interrupt 3) |
| Pin 47 | PD4 β Port D bit 4 (XCK1, USART1 clock) |
| Pin 48 | PD5 β Port D bit 5 (OC1A, Timer1 PWM output A) |
| Pin 49 | PD6 β Port D bit 6 (OC1B, Timer1 PWM output B) |
| Pin 50 | PD7 β Port D bit 7 (OC2, Timer2 PWM output) |
| Pin 51 | PG0 β Port G bit 0 (WR, external memory write strobe) |
| Pin 52 | PG1 β Port G bit 1 (RD, external memory read strobe) |
| Pin 53 | PG2 β Port G bit 2 (ALE, external memory address latch enable) |
| Pin 54 | XTAL1 β Inverted oscillator amplifier input / internal clock input |
| Pin 55 | XTAL2 β Inverted oscillator amplifier output |
| Pin 56 | PB0 β Port B bit 0 (SS, SPI slave select) |
| Pin 57 | PB1 β Port B bit 1 (SCK, SPI clock) |
| Pin 58 | PB2 β Port B bit 2 (MOSI, SPI master data out) |
| Pin 59 | PB3 β Port B bit 3 (MISO, SPI master data in) |
| Pin 60 | PB4 β Port B bit 4 (OC0, Timer0 PWM output) |
| Pin 61 | PB5 β Port B bit 5 (OC1C, Timer1 PWM output C) |
| Pin 62 | PB6 β Port B bit 6 (general purpose I/O) |
| Pin 63 | PB7 β Port B bit 7 (general purpose I/O) |
| Pin 64 | RESET β Reset input, active low (also used by JTAG/ISP programming) |
Typical Applications
ATMEGA165PA-AU is suitable for 6 applications: Industrial Automation Controllers, Battery-Powered Metering and Sensor Nodes, Consumer Appliance Control Panels, Motor Control Systems, Embedded Networking and Gateways, Test, Measurement and JTAG Debug Fixtures.
Industrial Automation Controllers
The ATMEGA165PA-AU fits industrial automation nodes where 53 GPIO lines, a hardware SPI for isolated fieldbus transceivers, and a USART for Modbus RTU are required in one 16MHz AVR core. Its 2.7V to 5.5V supply tolerance allows direct operation on a 5V industrial rail with the brown-out detector guarding against browned-out power events. The 16KB Flash with read-while-write support enables field firmware updates over the serial link without a second bootloader chip. The JTAG interface provides boundary-scan for production test of the assembled board and on-chip debugging during development, reducing test fixture complexity. Placed in a 64-TQFP with exposed routing on a standard 2-layer PCB, the device typically runs well below its 85C industrial ceiling in enclosed control cabinets.
Recommended
Battery-Powered Metering and Sensor Nodes
The picoPower sleep controller is the reason to select the ATMEGA165PA-AU over the non-P ATMEGA165A-AU in battery products. In power-down mode the device wakes on pin-change or watchdog interrupt, allowing a smart meter or environmental sensor to sleep in the microamp range for 99% of its duty cycle and wake only for a measurement burst. The 10-bit ADC with an internal reference reads sensor bridges directly, while the 512B EEPROM stores calibration data across battery replacement. Running at 8MHz from a 3V coin cell or two alkaline cells keeps the frequency-voltage product safe per the AVR derating curve. Estimated: at a 1% duty cycle with sleep current in the single-digit microamp range, average draw remains far below the continuous 16MHz active current, supporting multi-year battery life.
Recommended
Consumer Appliance Control Panels
Appliance main boards benefit from the ATMEGA165PA-AU combination of 5V-tolerant GPIO, three timers with PWM outputs for triac or relay control, and mature single-chip integration that eliminates external glue logic. The USART handles communication with display or communication modules, while SPI reads rotary encoders or touch controllers. The 64-TQFP (14x14 mm) package offers comfortable 0.5mm pitch routing on low-cost 2-layer consumer PCBs. The AVR 133-instruction single-cycle RISC core executes interrupt-driven button scanning and PWM generation with ample headroom at 16MHz. RoHS compliance and the industrial -40C to +85C rating simplify certification across global appliance standards, and the wide availability of second sources within the same footprint (ATMEGA165A/325A family) reduces single-part sourcing risk for high-volume production.
Recommended
Motor Control Systems
With one 16-bit timer providing three compare channels (OC1A/OC1B and the Timer3 PWM outputs on port PE) plus an 8-bit Timer0/Timer2 pair, the ATMEGA165PA-AU can generate multi-phase PWM for brushed DC and small BLDC motor drives. The 16MHz core executes commutation and current-loop interrupt service routines with deterministic single-cycle instruction timing, important for predictable PWM dead-time control. The 10-bit ADC samples shunt-resistor current feedback at standard free-running rates, and pin-change interrupts capture Hall sensor edges without external logic. A typical topology places the MCU on a 5V logic rail, driving an H-bridge gate driver over opto-isolated SPI or direct PWM lines. The brown-out detector prevents PWM-glitch shoot-through during supply dips, a common failure mode in underprotected motor boards.
Recommended
Embedded Networking and Gateways
As a bridge controller between serial field devices and Ethernet or wireless modules, the ATMEGA165PA-AU offers two communication angles: a hardware USART for protocol translation (Modbus, DMX, custom links) and hardware SPI for high-throughput links to ENC28J60-class Ethernet controllers or 802.15.4 radio modules. The 1KB SRAM constrains buffer depth, so designs should implement small fixed-size frame buffers or add external memory via the port-based bus interface. JTAG boundary-scan simplifies ICT fixture testing of densely routed network boards. Running the core at 16MHz from a 5V rail gives the widest safety margin for driving 5V RS-485 transceivers directly. The 64-TQFP layout with grouped ports PA-PC simplifies bus-style routing to parallel peripheral interfaces common in legacy gateway hardware.
Recommended
Test, Measurement and JTAG Debug Fixtures
The ATMEGA165PA-AU doubles as the intelligence inside production test fixtures and programming jigs: its JTAG port supports boundary-scan chain testing of target boards, while its GPIO fan-out of 53 lines drives backplane test points directly. The read-while-write Flash allows the firmware to log test results into internal Flash or EEPROM between power cycles of the device under test. SPI and USART links communicate with fixture relays, electronic loads, and host PCs over USB-serial converters. Using the same AVR family for both fixture and target reduces tooling complexity, since a single MPLAB SNAP or JTAGICE unit debugs both. Estimated: at 16MHz, a scan-cycle routine handling 50 GPIO test points completes in the low hundreds of microseconds, ample for high-throughput end-of-line stations.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA165PA-AU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA165A-AU | ATMEGA165P-16ANR | ATMEGA325PA-AU | ATMEGA169A-AU |
|---|---|---|---|---|---|
| Package | 64-TQFP (14x14 mm) | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 mm) - same | 64-TQFP (14x14 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 |
| Max Clock Speed | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| SRAM | 1 KB | 1 KB | 1 KB | 2 KB | 1 KB |
| picoPower Low-Power Modes | Yes | No | Yes | Yes | No |
| LCD Controller | No | No | No | No | Yes (segment LCD) |
| Supply Voltage Range | 2.7 V to 5.5 V | 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 |
| JTAG Debug/Boundary-Scan | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- picoPower sleep architecture (vs ATMEGA165A-AU)
- External memory bus interface (vs ATMEGA169A-AU)
- 64-TQFP with 53 GPIO in a single-chip solution (vs ATMEGA164PA-AUR)
Design Notes
Respect the AVR frequency-versus-voltage safety curve: 16MHz operation requires a 4.5V to 5.5V supply, while 2.7V operation supports roughly 8MHz maximum per the Microchip ATmega165A/PA datasheet. Exceeding this derating causes marginal core timing and intermittent failures, especially at temperature extremes. Decouple each VCC pin (pins 9, 21, 32) with 100nF ceramic capacitors placed within 2mm of the pin, and connect AVCC (pin 41) to VCC through an RC filter (10 ohm + 100nF plus 10uF bulk) when ADC accuracy matters.
The 64-TQFP 0.5mm-pitch leads require solder-mask-defined or non-solder-mask-defined pads per IPC-7351 guidance; verify your footprint against the Microchip package drawing before release. Route the JTAG pins (PF4-PF7, TCK/TMS/TDO/TDI) to a standard 2x5 header so MPLAB SNAP or JTAGICE can reach the device in-circuit. Keep the XTAL1/XTAL2 crystal traces short (under 15mm) and guard them with ground, since long traces invite stray oscillation during startup.
Configure the JTAGEN fuse deliberately: JTAG is enabled by default and steals PF4-PF7 (four of the eight ADC inputs) from general-purpose use. Disable JTAGEN via fuse programming if you need ADC4-ADC7, but note this also removes boundary-scan from production test. Also, when using the external memory interface on PA/PC/PG, remember those ports are consumed by the bus and unavailable as GPIO - budget your 53-pin count accordingly before finalizing the I/O map.
For battery designs, exploit the picoPower modes: enter power-down rather than idle when no timing continuity is needed, and use the Timer2 asynchronous mode with a 32.768kHz watch crystal (on PG3/PG4 TOSC pins) to keep a real-time clock alive in sleep. Estimated: a design waking once per second at 1% active duty from power-down achieves average currents orders of magnitude below the active-mode figure, translating to multi-year life on two AA cells.
Compliance Information
RoHS compliant per distributor listing of the -AU industrial package variant. AEC-Q100 automotive qualification is not claimed for this commercial/industrial grade part.