ATMEGA8515-16AJ - 8KB Flash AVR MCU 16MHz TQFP-44 | Microchip
MPN: ATMEGA8515-16AJ β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.94 | $1,470.00 |
| 1,000 | $2.65 | $2,650.00 |
ATMEGA8515-16AJ Overview
A microcontroller is a complete computing system on a single chip, combining a processor core, program memory, data memory, and peripherals. The ATmega8515 belongs to the 8-bit AVR RISC family, which sits within Microchip Technology's broader MCU portfolio of embedded processors. Its 130-instruction RISC architecture executes most instructions in a single clock cycle, and 32 general purpose working registers are directly connected to the ALU, delivering up to 16 MIPS at 16 MHz.
Key differentiating features include the external memory interface - rare among small AVRs - which expands SRAM to 64 KB for data-heavy applications. The peripheral set covers two flexible Timer/Counters with compare modes, a programmable Serial USART, a programmable Watchdog Timer with internal oscillator, an SPI serial interface, and 35 general purpose I/O lines.
Architecturally, the ATmega8515 uses a Harvard structure with separate program and data buses, enabling Read-While-Write self-programming Flash operation. The self-programming capability supports field firmware updates without an external programmer, while the enhanced power-save modes reduce consumption in battery-powered systems.
Typical applications include industrial control panels, legacy 8051-pinout system migrations (the ATmega8515 is 8051 pin-compatible in 44-pin packages), data loggers using external SRAM, embedded test equipment, and motor-adjacent control logic driven by the timer compare outputs.
Design-wise, the J suffix denotes a lead-free TQFP package; the A suffix identifies the ATmega8515A silicon revision, so always confirm bootloader and fuse compatibility with the A-variant datasheet when migrating from original ATmega8515 parts.
This page synthesizes distributor availability, verified drop-in alternatives, and practical design guidance not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8515-16AJ 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 ATMEGA8515-16AJ (same form factor and footprint) β differing in EEPROM, Instructions, Package, Working Registers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA8515-16AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA8515-16AI
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA162-16AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.45 / Unit
View Datasheet βATMEGA8515-16AJ Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 8 KB In-System Programmable (Read-While-Write) |
| EEPROM | 512 bytes |
| Internal SRAM | 512 bytes |
| External SRAM Support | Up to 64 KB |
| Max Throughput | 16 MIPS at 16 MHz |
| Max Clock Frequency | 16 MHz |
| Instructions | 130 powerful instructions, most single-cycle |
| Working Registers | 32 general purpose |
| General Purpose I/O | 35 lines |
| Timers | Two Timer/Counters with compare modes |
| Serial Interfaces | USART, SPI |
| Watchdog Timer | Programmable with internal oscillator |
| Package | 44-TQFP |
| Mounting Type | Surface Mount |
| External Memory Interface | Yes |
ATMEGA8515-16AJ 44-tqfp Pin Configuration Guide
Pin configuration for ATMEGA8515-16AJ (44-tqfp 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 ATMEGA8515-16AJ.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA8515-16AJ is suitable for 6 applications: Industrial Control Panels, 8051 Legacy System Migration, External-SRAM Data Loggers, Embedded Test and Measurement Equipment, Hobbyist and Educational AVR Development, Timed Actuator and PWM Control Systems.
Industrial Control Panels
The ATMEGA8515-16AJ fits industrial control panels because its 35 GPIO lines, two Timer/Counters with compare modes, and programmable Watchdog Timer cover the I/O and safety requirements of relay sequencing, button scanning, and status indication. Running at 16 MIPS from the single-cycle AVR RISC core, it executes polling loops fast enough for millisecond-level control tasks without an RTOS. The Watchdog with its own internal oscillator provides autonomous fault recovery, a requirement in unattended factory equipment. The 5 V-tolerant industrial supply range and wide temperature qualification suit electrically noisy panel environments, and SPI plus USART handle supervisory communication to PLCs or HMI displays.
Recommended
8051 Legacy System Migration
The ATmega8515 was expressly designed as an 8051 pin-compatible performance upgrade, so the ATMEGA8515-16AJ can populate an existing 8051-style 44-pin TQFP PCB without layout change. Engineers gain 16 MIPS at 16 MHz - roughly an order of magnitude beyond a 12 MHz classic 8051 - while retaining the same socket, crystal, and bus connections. The external memory interface preserves designs that used external EPROM/RAM, though firmware must be ported since the instruction sets differ. This migration path refreshes obsolete 8051 inventory risk while extending product life; the self-programming Flash then enables field updates the original mask-ROM 8051 could never offer.
Recommended
External-SRAM Data Loggers
Data loggers benefit directly from the ATmega8515's signature external memory interface, which addresses up to 64 KB of SRAM - 128x the internal 512 bytes - for buffering ADC samples before writing to storage. PORTA serves as the multiplexed address/data bus and PORTC supplies high-order address lines with ALE latching, per the Microchip datasheet. At 16 MHz, bus cycles are fast enough to sustain continuous logging of multichannel sensors at kilohertz rates. Combined with the 512 bytes EEPROM for configuration persistence and the USART for data offload, one ATMEGA8515-16AJ plus one SRAM chip and a real-time clock forms a complete mid-rate acquisition node.
Recommended
Embedded Test and Measurement Equipment
Bench instruments and rack accessories use the ATMEGA8515-16AJ for front-panel control, relay matrix switching, and trigger generation. The compare-mode Timer/Counters produce precise, hardware-timed pulses for stimulus generation, while the SPI interface drives DACs, digitizer front-ends, and display controllers. Deterministic single-cycle instruction execution makes interrupt latency predictable - important for time-correlated measurements. Its 5 V logic levels interface naturally with legacy instrumentation buses and optocoupled inputs, and the 44-TQFP with 35 I/O handles the switch matrix sizes typical of small automated test fixtures without additional port expanders.
Recommended
Hobbyist and Educational AVR Development
The ATmega8515 remains popular in education and hobbyist projects because the open-source MajorCore Arduino package supports the full ATmega8515 family with the Urboot bootloader, bringing modern Arduino tooling to this legacy part. Its external memory interface lets students experiment with memory systems - address latching, bus multiplexing - that simpler AVRs hide, making it an excellent teaching platform for computer architecture fundamentals. The 44-pin DIP sibling allows breadboard prototyping before migrating to the ATMEGA8515-16AJ TQFP for final assembly. Community documentation, datasheets, and programming guides are abundant, lowering the entry barrier for learners.
Recommended
Timed Actuator and PWM Control Systems
Systems controlling heaters, lamps, valves, or small DC motors use the ATMEGA8515-16AJ's hardware compare outputs - OC0, OC1A, OC1B, and OC2 - for glitch-free PWM generation independent of software jitter. The two Timer/Counters with compare modes support dual independent PWM channels plus a third from Timer0, sufficient for two-motor or motor-plus-heater combinations. At 16 MHz, PWM resolution reaches the full 8-bit range at frequencies suitable for thermal and actuator control. The USART provides setpoint updates from a supervisory controller, and the Watchdog Timer guarantees actuator shutdown on firmware lockup - a common safety requirement in heating and pumping equipment.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8515-16AJ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8515-16AU | ATMEGA8515-16AI | ATMEGA162-16AU |
|---|---|---|---|---|
| Package | 44-TQFP | 44-TQFP - same | 44-TQFP - same | 44-TQFP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 8 KB | 8 KB | 8 KB | 16 KB |
| EEPROM | 512 bytes | 512 bytes | 512 bytes | 512 bytes |
| Internal SRAM | 512 bytes | 512 bytes | 512 bytes | 1 KB |
| Max Clock / Throughput | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS |
| External Memory Interface | Yes, up to 64 KB | Yes, up to 64 KB | Yes, up to 64 KB | Yes, up to 64 KB |
Key Differentiators
- External memory interface up to 64 KB (vs ATMEGA8-16PI)
- 8051 pin compatibility in TQFP-44 (vs ATMEGA162-16AU)
- Lead-free green TQFP packaging (vs ATMEGA8515-16PI)
Design Notes
Verify the suffix migration before ordering: ATMEGA8515-16AJ is an 'A' silicon revision in the green/lead-free TQFP package. Designs written against original (non-A) ATmega8515 errata should be re-checked against the Microchip ATmega8515A datasheet (document 2512S) for any fuse, calibration byte, or timing differences. When replacing ATMEGA8515-16PC (PDIP) boards, remember the TQFP footprint is completely different - only the AJ/AU/AI TQFP suffixes are interchangeable on the same PCB.
The 16 MHz speed grade requires the high-voltage operating range (4.5 V to 5.5 V family rating per Microchip); running below this range at 16 MHz violates the frequency-versus-voltage guarantee. Decouple each VCC pin with 100 nF ceramics placed within a few millimeters of the pins, plus one bulk capacitor per supply rail. If using the external memory bus at full speed, keep bus trace lengths short and consider adding series termination on the multiplexed PORTA lines to reduce ringing.
For the 44-TQFP, fan out with via-in-avoid patterns under the package center and reserve a solid ground plane on layer 2. Place the 16 MHz crystal within 10 mm of XTAL1/XTAL2 with load capacitors close to ground. When the external SRAM interface is used, route PORTA (multiplexed data/low address) and PORTC (high address) as short matched groups and latch the low address on ALE with minimal skew - excess ALE-to-address setup violation is the most common cause of intermittent external-memory faults.
Compliance Information
The 'J' packaging suffix in Microchip/Atmel part numbering denotes lead-free (Pb-free) green packaging. REACH, halogen-free, and conflict-minerals status not stated in provided data.
