ATMEGA165-16AI - 8-bit AVR MCU 16KB Flash 16MHz 64-TQFP | Microchip
MPN: ATMEGA165-16AI β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.7 | $47.00 |
| 100 | $4.15 | $415.00 |
| 500 | $3.8 | $1,900.00 |
| 1,000 | $3.45 | $3,450.00 |
ATMEGA165-16AI 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, the ATmega family sits in the general-purpose MCU class, bridging small 8-pin AVRs and larger 128KB devices. The ATmega165 is the non-LCD sibling of the ATmega169, sharing the same core, memory map and 64-pin TQFP footprint.
Key features include 130 powerful instructions with mostly single-cycle execution, eight general-purpose 8-bit working registers, fully static operation, and up to 16 MIPS throughput at 16MHz. The part provides in-system programmable FLASH with optional boot-code section for in-application programming, plus JTAG boundary-scan and on-chip debugging support typical of the ATmega165/169 device family.
Architecturally, the ATmega165 uses the AVR enhanced RISC pipeline with a single-level instruction fetch/decode stage, allowing one instruction per clock cycle for most opcodes. Program memory is organized as 8K x 16 bits, and the chip integrates SRAM, EEPROM, timers, USART serial port, SPI interface, an 8-channel 10-bit ADC, and multiple low-power sleep modes that make it well suited to battery-operated designs.
Typical applications include industrial control panels, sensor front ends and data loggers, HVAC and building automation nodes, and legacy embedded systems that require a proven 8-bit platform with ISP field upgrades. The 64-pin TQFP gives generous I/O count for keypads, displays and peripheral expansion.
When designing with the ATMEGA165-16AI, verify the supply voltage range against the specific datasheet table for this speed/temperature grade, decouple VCC and AVCC separately, and use the ISP interface (via the SPI pins) for production programming. Keep the JTAG pins in mind if boundary scan is required, as they double as general-purpose port pins after fuse programming.
This page synthesizes distributor availability, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with pricing and stock references as of 2026-09-16.
Drop-in alternatives for ATMEGA165-16AI 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 ATMEGA165-16AI (same form factor and footprint) β differing in Package, Instruction Set, Core Processor, Flash Memory, Operating Temperature.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA165-16AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA165A-AU
β Drop-Inβ In Stock
$3.47 / Unit
View Datasheet βATMEGA165PA-AU
β Drop-Inβ In Stock
$2.05 / Unit
View Datasheet βATMEGA165V-8AU
β Drop-Inβ In Stock
$3.12 / Unit
View Datasheet βATMEGA169-16AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA169-16AI
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA165-16AI Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR enhanced RISC, 8-bit |
| Flash Memory | 16 KB (8K x 16) In-System Programmable |
| Maximum Clock Frequency | 16 MHz |
| Peak Throughput | 16 MIPS (at 16 MHz) |
| Instruction Set | 130 instructions, most single-cycle |
| Working Registers | 8 x general purpose 8-bit registers |
| Package | 64-TQFP (14 x 14 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (Industrial) |
| Debug/Scan | JTAG on-chip debug and boundary scan (per family datasheet) |
| Programming | In-System Programmable (ISP) via SPI |
ATMEGA165-16AI 64-tqfp (14 x 14 mm) Pin Configuration Guide
Pin configuration for ATMEGA165-16AI (64-tqfp (14 x 14 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 ATMEGA165-16AI.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA165-16AI is suitable for 6 applications: Industrial Control Panels, Sensor Nodes and Data Loggers, HVAC and Building Automation, Legacy Embedded System Maintenance, Consumer Appliance Control, Test and Measurement Fixtures.
Industrial Control Panels
The ATMEGA165-16AI's -40C to +85C industrial temperature grade and deterministic AVR RISC core make it a strong fit for industrial control panels that sequence relays, read keypads and drive status indicators. The 64-pin TQFP exposes ample GPIO for front-panel I/O, while the 16KB ISP FLASH accommodates typical control firmware with headroom for field updates via a boot-loader. Its USART and SPI interfaces link to HMI expanders, EEPROM logging and RS-485 transceivers, and single-cycle instruction execution provides predictable scan timing for debounce loops and timing-critical interlocks without an RTOS.
Recommended
Sensor Nodes and Data Loggers
For battery-backed sensor nodes, the ATmega165 family's fully static core and multiple sleep modes let the ATMEGA165-16AI idle between acquisition cycles, while the on-chip ADC digitizes analog sensors without an external converter. The 16MHz grade provides throughput headroom for filtering and scaling in firmware, and the SPI bus interfaces to SD-card or serial-FLASH logging media. The 64-TQFP footprint supports multi-channel analog front ends, and the picoPower ATMEGA165PA-AU drop-in offers a low-power redesign path without PCB changes when battery life becomes a constraint.
Recommended
HVAC and Building Automation
Building automation controllers benefit from the ATMEGA165-16AI's combination of 16KB ISP FLASH for protocol stacks, USART for RS-485 MODBUS-style links, and generous port count for damper drives, valve outputs and sensor inputs on one 64-TQFP device. The industrial temperature rating covers rooftop and mechanical-room environments, and in-system programmability allows firmware updates of installed units through the boot-loader without removing controllers from the wall. Deterministic 16 MIPS execution supports fixed-time-step PID loops for temperature control with stable, jitter-free timing.
Recommended
Legacy Embedded System Maintenance
Many installed AVR-based boards were designed around the original ATmega165 die; the ATMEGA165-16AI serves form-fit-function maintenance of those systems. Verified cross-references show ATMEGA169-16AU as a complete replacement with consistent terminals and package, and the ATMEGA165A/PA revisions as newer-silicon drop-ins, giving procurement several sourcing lanes when the original grade is constrained. Because the instruction set and pinout are unchanged, existing HEX images program identically via SPI ISP, minimizing requalification for repair-and-continue production of legacy equipment.
Recommended
Consumer Appliance Control
Appliance control boards - coffee machines, washing-machine user interfaces, small heater controllers - historically used 64-pin ATmega devices for their keypad matrices, LED columns and triac-driving port count. The ATMEGA165-16AI supplies 16 MIPS for UI scanning, the ADC for NTC temperature sensing, and the USART for service-diagnostic links, all on one 64-TQFP (14x14 mm) footprint. Where mains zero-cross timing drives triacs, single-cycle instruction execution keeps interrupt latency low. The 16AU commercial-grade sibling can be chosen where the ambient profile permits, reducing cost in consumer housings.
Recommended
Test and Measurement Fixtures
Bench fixtures and automated test equipment often pair an ATmega-class MCU with instrumentation interfaces. The ATMEGA165-16AI's JTAG boundary-scan capability supports board-level interconnect testing during fixture development, while the SPI and USART ports drive DACs, digitizers and PC links. The 16KB ISP FLASH holds fixture sequences that can be field-reprogrammed as products change, and the industrial temperature grade keeps fixtures stable in non-climate-controlled production areas. The shared 64-TQFP footprint with ATMEGA169 variants lets one fixture PCB serve multiple firmware builds.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA165-16AI β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA165-16AU | ATMEGA165A-AU | ATMEGA165PA-AU | ATMEGA165V-8AU | ATMEGA169-16AU |
|---|---|---|---|---|---|---|
| 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 | 64-TQFP (14x14 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) | Microchip Technology (Atmel) |
| Flash Memory | 16 KB ISP FLASH | 16 KB | 16 KB | 16 KB | 16 KB | 16 KB |
| Maximum Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 8 MHz | 16 MHz |
| LCD Controller | No | No | No | No | No | Yes (integrated LCD driver) |
| Power Technology | Standard AVR core | Standard AVR core | Standard AVR core (A revision) | picoPower (lower sleep current) | V-grade wide/lower voltage range | Standard AVR core |
| Drop-in Compatibility | Reference part | Yes - same die, temp grade differs | Yes - newer silicon revision | Yes - picoPower revision | Yes - 8MHz max, verify firmware | Yes - FindIC: complete replacement |
Key Differentiators
- Industrial temperature grade without LCD overhead (vs ATMEGA169-16AU)
- Full 16MHz throughput on original die (vs ATMEGA165V-8AU)
- Newer-silicon sourcing flexibility (vs ATMEGA165A-AU / ATMEGA165PA-AU)
Design Notes
Verify the supply voltage window for the -16AI speed/temperature grade directly in the ATmega165 datasheet tables before fixing the rail; AVR '16' grades and 'V' grades have different voltage ranges, and running a non-V grade below its specified minimum can cause unstable execution at 16MHz. Decouple VCC and AVCC independently with 100nF ceramics placed within 5mm of the pins, and connect AVCC to VCC through a low-pass LC filter when the ADC is active to protect the 10-bit converter from digital rail noise.
On the 64-TQFP (14x14 mm) land pattern, bring the ISP pins (MOSI, MISO, SCK, RESET, VCC, GND) to a tagged header or test pads, since all production programming and boot-loader recovery happens through SPI ISP. If JTAG boundary scan or on-chip debug is planned, route the four JTAG pins to a 2x5 header; otherwise they can be fuse-disabled and reused as port pins. Keep crystal traces for XTAL1/XTAL2 short (under 15mm) with guard ground for reliable 16MHz operation.
A frequent migration pitfall: the pin-compatible ATMEGA169-16AU adds an LCD controller whose pins overlap port pins on the ATmega165; firmware that drives those ports as general-purpose I/O will still work, but verify that no fuse defaults enable the LCD block after swap. Also confirm each candidate revision (A, PA) errata sheet before production - silicon revisions can change timer and USART edge behavior. Finally, reserve RESET as programming-only; disabling RESET for GPIO use complicates ISP recovery.
Compliance Information
Compliance status not stated in the provided verified web data; confirm on the Microchip product compliance page before specification.