ATMEGA8515-16AC - 8-bit AVR MCU 16MHz 8KB Flash | Microchip
MPN: ATMEGA8515-16AC β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $3.02 | $1,510.00 |
| 1,000 | $2.72 | $2,720.00 |
ATMEGA8515-16AC Overview
A microcontroller unit (MCU) integrates a processor core, program memory, data memory, and peripherals on a single die, sitting at the top of the embedded-control hierarchy (MCU -> embedded processor -> integrated circuit -> semiconductor). The AVR family uses an enhanced Harvard RISC architecture in which most of its 130 instructions execute in a single clock cycle, and 32 general-purpose working registers are directly connected to the ALU.
Key features include 8 KB self-programming Flash with Read-While-Write capability, up to 64 KB of external memory expansion through a parallel External Memory Interface (EBI/EMI), 35 general-purpose I/O lines, and connectivity via SPI, USART, and TWI (I2C-compatible) interfaces. Two flexible Timer/Counters with compare modes, internal and external interrupt sources, and a programmable Watchdog Timer round out the peripheral set. The 16AC speed grade sustains full 16 MHz operation at a commercial temperature range with a 4.5V to 5.5V supply.
Architecturally, the single-stage pipelined AVR core fetches one instruction while executing the next, achieving near one-MIPS-per-MHz efficiency. Fully static operation allows clocking down to DC for ultra-low-power sleep modes without register loss, while self-programming Flash enables field firmware updates and bootloaders.
Typical applications include industrial control panels using the external memory interface, legacy AVR system maintenance and repair, and motor/actuator control leveraging the timer compare outputs.
Design tip: if your firmware uses less than 8 KB Flash and no external bus, pin-compatible higher-density family members reduce obsolescence risk; always verify the JTAG and EBI pin mapping before board reuse.
This page synthesizes distributor availability data, drop-in alternative options, and practical design guidance not consolidated in the manufacturer datasheet. Pricing shown is as of 2026-09-18.
Drop-in alternatives for ATMEGA8515-16AC 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 ATMEGA8515-16AC (same form factor and footprint) β differing in Communication Interfaces, Core Architecture, Package, EEPROM, Instruction Set.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA8515-16AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA8515-16AI
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA8515L-8AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA16-16AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$4.41 / Unit
View Datasheet βATMEGA16A-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.05 / Unit
View Datasheet βATMEGA8515-16AC Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Maximum Clock Frequency | 16 MHz |
| Throughput | 16 MIPS at 16 MHz |
| Flash Program Memory | 8 KB (4K x 16), In-System Programmable |
| EEPROM | 512 bytes |
| Internal SRAM | 512 bytes |
| External Memory Support | Up to 64 KB external SRAM |
| Instruction Set | 130 instructions, most single-cycle |
| Working Registers | 32 general purpose x 8-bit |
| General Purpose I/O | 35 lines |
| Communication Interfaces | SPI, USART, TWI, EBI/EMI |
| Timers | Two Timer/Counters with compare modes |
| Watchdog Timer | Programmable, on-chip |
| Supply Voltage | 4.5 V to 5.5 V (16 speed grade) |
| Operating Temperature | 0 C to +70 C (commercial, AC suffix) |
| Package | 44-pin TQFP, 10x10 mm |
| Mounting Type | Surface Mount |
ATMEGA8515-16AC 44-pin tqfp, 10x10 mm Pin Configuration Guide
Pin configuration for ATMEGA8515-16AC (44-pin tqfp, 10x10 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 ATMEGA8515-16AC.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA8515-16AC is suitable for 6 applications: Industrial Control Panels, Legacy AVR System Maintenance and Repair, Embedded Data Acquisition and External Memory Expansion, Motor and Actuator PWM Control, Educational and Training Platforms, Communication Nodes with SPI, UART and TWI.
Industrial Control Panels
The ATMEGA8515-16AC fits industrial control panel designs that need parallel bus expansion, thanks to its dedicated External Memory Interface supporting up to 64 KB of external SRAM and 35 general-purpose I/O lines. In this role the MCU addresses legacy alphanumeric LCD modules, relay banks, and keypad matrices directly from Port A through Port D while keeping the deterministic 16 MIPS AVR core for scan loops. The two Timer/Counters with compare modes generate timing references for sequenced outputs, and the programmable Watchdog Timer provides the autonomous fault reset expected in industrial environments. Because the 16AC operates on a 4.5V-5.5V rail, it interfaces directly with legacy 5V PLC-style logic without level translation. For panel environments below 0 C or above +70 C, specify the industrial-grade ATMEGA8515-16AU instead - same footprint, extended temperature.
Recommended
Legacy AVR System Maintenance and Repair
Maintaining and repairing older AVR-based equipment is one of the strongest use cases for the ATMEGA8515-16AC, since many 1990s-2000s designs were built around the ATmega8515 external-memory bus architecture. Drop-in replacement on the original TQFP-44 footprint restores functionality without PCB modification, and firmware recovered via SPI ISP programming or high-voltage parallel programming can be reflashed onto the new die. The 16 MHz/16 MIPS speed grade and 4.5V-5.5V supply match the original electrical envelope, so calibration constants and fuse settings transfer unchanged. Field engineers value the self-programming Flash, which allows a USART-based bootloader to update units on site without desoldering the MCU. Keep the ATMEGA8515L-8AU as a second source for units whose clock circuits run at 8 MHz rather than 16 MHz.
Recommended
Embedded Data Acquisition and External Memory Expansion
Designs that sample analog or digital inputs and buffer substantial data benefit from the ATMEGA8515-16AC external memory interface, which addresses up to 64 KB of external SRAM over the parallel bus - 128x its internal 512 bytes. Typical topologies latch the Port A address bus with a 74HC573-style latch and multiplex data through the same port, freeing two full ports for sensors and communication. At 16 MIPS the core can service USART-based telemetry at 115200 baud while polling a SPI ADC, and the TWI master can pull data from remote sensor nodes. The commercial 0 C to +70 C range of the 16AC suits bench instruments and indoor gateways; outdoor deployments should use the AU industrial variant. Note the 5V-only supply requires level shifters for 3.3V peripherals.
Recommended
Motor and Actuator PWM Control
The ATMEGA8515-16AC generates motor and actuator drive signals using its two Timer/Counters with compare modes, which produce PWM outputs with adjustable duty cycle and frequency without CPU intervention. At a 16 MHz clock the timer resolution supports 8-bit PWM at roughly 62.5 kHz or slower, audio-free frequencies for DC motor drivers, and the 35 GPIO lines switch direction, enable, and limit-switch inputs concurrently. The AVR core's single-cycle ALU closes simple PI loops at kilohertz rates, sufficient for fan, pump, and conveyor actuation. The programmable Watchdog Timer enforces recovery from firmware lockups, a safety expectation in motion control. Since the 16AC is rated only 0 C to +70 C on 4.5V-5.5V, harsh installations should substitute the identical ATMEGA8515-16AU industrial part without layout change.
Recommended
Educational and Training Platforms
The ATMEGA8515-16AC remains popular in university embedded-systems labs because the AVR architecture is transparent, the 130-instruction set is learnable in a semester, and the external memory interface lets students wire their own SRAM and latch circuits - an exercise impossible on modern single-chip MCUs. The 5V supply and 44-pin TQFP are friendly to breadboard adapters and ZIF sockets, and SPI ISP programming requires only four signal lines from low-cost programmers. At 16 MIPS the chip runs full laboratory projects - digital clocks, serial terminals, simple RTOS kernels - with margin. The commercial temperature range is appropriate for classroom use. Courses migrating to newer silicon can use the ATMEGA48PA family for basic labs while keeping the 8515 for the bus-interfacing module.
Recommended
Communication Nodes with SPI, UART and TWI
As a communication node controller, the ATMEGA8515-16AC concurrently operates three serial channels: a hardware USART for RS-232/RS-485 links, a hardware SPI for fast peripheral interchange with ADCs, EEPROMs, and displays, and a TWI (I2C-compatible) master or slave for board-level sensor networks. The 16 MHz clock supports the full USART rate set including 115200 baud with low error, and SPI can clock into the MHz range for high-throughput transfers. The 35 GPIO lines drive addressing jumpers, status LEDs, and node-select signals, while the Watchdog re-initializes the stack after bus faults. Applications include Modbus-style field nodes, protocol bridges, and test fixtures. Designs needing 3.3V operation or USB should look at ATmega32U2-class devices instead, as the 16AC is strictly a 5V part.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8515-16AC β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8515-16AU | ATMEGA8515-16AI | ATMEGA8515L-8AU | ATMEGA16A-AU |
|---|---|---|---|---|---|
| Package | TQFP-44 (10x10) | TQFP-44 (10x10) - same | TQFP-44 (10x10) - same | TQFP-44 (10x10) - same | TQFP-44 (10x10) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Program Memory | 8 KB | 8 KB | 8 KB | 8 KB | 16 KB |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 8 MHz | 16 MHz |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V | 4.5 V to 5.5 V (16A grade) |
| SRAM / EEPROM | 512 B / 512 B | 512 B / 512 B | 512 B / 512 B | 512 B / 512 B | 1 KB / 512 B |
| External Memory Interface | Yes, up to 64 KB | Yes, up to 64 KB | Yes, up to 64 KB | Yes, up to 64 KB | Limited (not ATmega8515-equivalent EBI) |
| Key Special Feature | 8 KB self-programming Flash, EMI bus | Industrial temp, same die | Industrial temp, same die | 2.7 V low-voltage operation | JTAG on-chip debug, 16 KB Flash |
Key Differentiators
- Dedicated External Memory Interface up to 64 KB (vs ATMEGA16A-AU)
- Commercial vs industrial temperature flexibility on the same die (vs ATMEGA8515-16AU)
- Full 16 MHz / 5V speed grade for legacy buses (vs ATMEGA8515L-8AU)
Design Notes
The 16AC speed grade requires a 4.5V to 5.5V supply when running above 8 MHz per the Microchip ATmega8515 datasheet. Decouple VCC with 0.1 uF ceramic capacitors at all four VCC pins of the TQFP-44 plus one bulk 10 uF capacitor per supply rail. If the board must also support the ATMEGA8515L-8AU low-voltage variant, design the regulator for a switchable 3.3V/5V rail - the footprint accepts both parts. Never power the 16AC from an unregulated 5V rail that can exceed 5.5V during transients, as the absolute maximum will be violated.
Place the SPI ISP header (MOSI, MISO, SCK, RESET, GND, VCC) within easy reach of the MCU so firmware can be updated without desoldering. Route the external memory interface bus (Port A multiplexed address/data) with matched lengths when the external SRAM operates near the maximum 16 MHz bus rate, and add 22-33 ohm series resistors on strobe lines to reduce ringing. Keep the RESET trace short and add a 10 kohm pull-up plus 100 nF to ground for reliable power-on reset in noisy industrial environments.
The most common failure when migrating between ATmega8515 variants and sibling parts such as the ATmega16 is assuming full pin-for-pin peripheral equivalence - the External Memory Interface and timer register maps differ, so firmware must be recompiled and reviewed even when the TQFP-44 footprint is identical. Verify fuse settings (clock source, SPIEN, BOOTRST) before field deployment; an incorrect fuse on a fresh board can render the device inaccessible without high-voltage parallel programming. Also confirm RoHS and date-code compliance of older stock, since legacy AVR inventory may predate lead-free conversion.
Compliance Information
Compliance status for the specific 16AC ordering code was not stated in the retrieved web data. Verify on the Microchip product page (microchip.com/en-us/product/ATmega8515) or distributor listing (DigiKey/Mouser) before ordering.
