ATMEGA8515-16PJ - 8-Bit AVR MCU 16MHz 8KB Flash | Microchip
MPN: ATMEGA8515-16PJ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.62 | $4.62 |
| 10 | $4.16 | $41.60 |
| 100 | $3.71 | $371.00 |
| 500 | $3.34 | $1,670.00 |
| 1,000 | $2.99 | $2,990.00 |
ATMEGA8515-16PJ Overview
An 8-bit AVR microcontroller (MCU) is a single-chip integrated circuit that combines a RISC processor core, program memory (Flash), data memory (SRAM), non-volatile EEPROM, and peripherals such as timers, UART, SPI, and GPIO on one die. Within the semiconductor hierarchy, the ATmega8515 belongs to the ATmega family of AVR microcontrollers, which sit under the broader categories of microcontroller units (MCUs), embedded processors, and integrated circuits.
Key features include the AVR enhanced RISC architecture executing 130 powerful instructions - most in a single clock cycle - 32 general purpose working registers, 35 programmable I/O lines, two flexible Timer/Counters with compare modes, a dedicated 8-bit Timer/Counter with PWM (OC0), and internal plus external interrupt sources. The 16 MHz speed grade (-16 suffix) supports full 16 MIPS performance across the industrial voltage range.
A defining strength of the ATmega8515 is its external memory interface: address latching via ALE, plus dedicated /RD and /WR strobes allow direct connection of up to 64 KB of external SRAM. The port layout is deliberately 8051-footprint-oriented on the 40-pin PDIP, which historically enabled migration from classic 8051 designs to AVR with minimal PCB changes.
Typical applications include legacy industrial control systems, test jigs and instrumentation, motor control and relay sequencing panels, hobby and educational platforms, and systems requiring UART, SPI, and external RAM expansion at low cost.
When designing with this part, remember the 512 B internal SRAM limit: any larger data structures must live in external SRAM accessed through the XMEM interface, which consumes Port A and Port C as address/data buses and reduces available GPIO.
This page synthesizes verified distributor data, drop-in alternatives, pinout guidance, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8515-16PJ — 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 ATMEGA8515-16PJ (same form factor and footprint) — differing in Package, Communication Interfaces, Mounting Type, Operating Temperature, EEPROM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8515-16PU
✅ Drop-In✓ In Stock
$3.71 / Unit
View Datasheet →ATMEGA8515-16PI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.18 / Unit
View Datasheet →ATMEGA8515-16AUR
✅ Drop-In✓ In Stock
$2.35 / Unit
View Datasheet →ATMEGA8-16PI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.85 / Unit
View Datasheet →ATMEGA16-16PU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.88 / Unit
View Datasheet →ATMEGA8515-16PJ Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Maximum Clock Frequency | 16 MHz |
| Throughput | 16 MIPS at 16 MHz |
| Flash Program Memory | 8 KB (4K x 16) |
| SRAM | 512 B |
| EEPROM | 512 B |
| External Memory Support | up to 64 KB SRAM |
| General Purpose I/O | 35 lines |
| Working Registers | 32 x 8-bit |
| Instruction Set | 130 instructions, most single-cycle |
| Timers/Counters | Two flexible with compare modes + 8-bit Timer0 (OC0/PWM) |
| Communication Interfaces | UART, SPI |
| Interrupts | Internal and external interrupt sources |
| Package | 40-PDIP |
| Mounting Type | Through Hole |
ATMEGA8515-16PJ Pin Configuration
| Pin 1 | PB0 (SS/AIN0) — Port B bit 0 / SPI slave select / analog comparator input |
| Pin 2 | PB1 (T1/AIN1) — Port B bit 1 / Timer1 external clock / analog comparator input |
| Pin 3 | PB2 — Port B bit 2 |
| Pin 4 | PB3 — Port B bit 3 |
| Pin 5 | PB4 (OC0) — Port B bit 4 / Timer0 output compare / PWM output |
| Pin 6 | PB5 (MOSI/DI) — Port B bit 5 / SPI Master Out Slave In / ISP data input |
| Pin 7 | PB6 (MISO/DO) — Port B bit 6 / SPI Master In Slave Out / ISP data output |
| Pin 8 | PB7 (SCK/UCLOCK) — Port B bit 7 / SPI serial clock / ISP clock |
| Pin 9 | RESET — Active-low reset input; held low for SPI serial programming |
| Pin 10 | PD0 (RXD) — Port D bit 0 / UART receive data |
| Pin 11 | PD1 (TXD) — Port D bit 1 / UART transmit data |
| Pin 12 | PD2 (INT0) — Port D bit 2 / External interrupt 0 |
| Pin 13 | PD3 (INT1) — Port D bit 3 / External interrupt 1 |
| Pin 14 | PD4 — Port D bit 4 / Timer1 external events / compare output function |
| Pin 15 | PD5 — Port D bit 5 / Timer1 output compare function |
| Pin 16 | PD6 — Port D bit 6 / Timer1 input capture function |
| Pin 17 | PD7 — Port D bit 7 / Timer2 output compare function |
| Pin 18 | XTAL2 — Inverting oscillator amplifier output / internal clock output |
| Pin 19 | XTAL1 — Inverting oscillator amplifier input / external clock input |
| Pin 20 | GND — Ground |
| Pin 21 | PC0 (A8) — Port C bit 0 / external memory address line A8 |
| Pin 22 | PC1 (A9) — Port C bit 1 / external memory address line A9 |
| Pin 23 | PC2 (A10) — Port C bit 2 / external memory address line A10 |
| Pin 24 | PC3 (A11) — Port C bit 3 / external memory address line A11 |
| Pin 25 | PC4 (A12) — Port C bit 4 / external memory address line A12 |
| Pin 26 | PC5 (A13) — Port C bit 5 / external memory address line A13 |
| Pin 27 | PC6 (A14) — Port C bit 6 / external memory address line A14 |
| Pin 28 | PC7 (A15) — Port C bit 7 / external memory address line A15 |
| Pin 29 | RD — External memory read strobe (active low) |
| Pin 30 | ALE — External memory address latch enable |
| Pin 31 | WR — External memory write strobe (active low) |
| Pin 32 | PA7 (AD7) — Port A bit 7 / multiplexed address-data line AD7 |
| Pin 33 | PA6 (AD6) — Port A bit 6 / multiplexed address-data line AD6 |
| Pin 34 | PA5 (AD5) — Port A bit 5 / multiplexed address-data line AD5 |
| Pin 35 | PA4 (AD4) — Port A bit 4 / multiplexed address-data line AD4 |
| Pin 36 | PA3 (AD3) — Port A bit 3 / multiplexed address-data line AD3 |
| Pin 37 | PA2 (AD2) — Port A bit 2 / multiplexed address-data line AD2 |
| Pin 38 | PA1 (AD1) — Port A bit 1 / multiplexed address-data line AD1 |
| Pin 39 | PA0 (AD0) — Port A bit 0 / multiplexed address-data line AD0 |
| Pin 40 | VCC — Digital supply voltage |
Typical Applications
ATMEGA8515-16PJ is suitable for 6 applications: Legacy Industrial Control Systems, External SRAM Data Logging Systems, Motor Control and Relay Sequencing Panels, Educational and Hobbyist Embedded Platforms, Test Jigs and Bench Instrumentation, Embedded Communication Nodes (UART/SPI).
Legacy Industrial Control Systems
The ATMEGA8515-16PJ fits industrial control retrofits because it combines 35 GPIO lines, two flexible Timer/Counters with compare modes, and a 16 MHz core able to run deterministic control loops at 16 MIPS. Its 8051-oriented 40-pin PDIP footprint lets engineers drop the AVR into boards originally designed around classic 8051 microcontrollers, preserving relay-driving and optocoupler-interface circuits. In a typical panel, PD0-PD7 drive UART communications to an HMI while Port B handles SPI-connected ADCs or EEPROM. The 8 KB Flash accommodates structured control firmware with communications stacks; the XMEM interface can add 32 KB external SRAM when logging data. Because the part is a mature Microchip product, long-term sourcing through distributors like DigiKey remains practical, as of 2026-09-18.
Recommended
External SRAM Data Logging Systems
The defining application of the ATMEGA8515-16PJ is data logging that exceeds its 512 B internal SRAM. The built-in external memory (XMEM) interface addresses up to 64 KB of external SRAM: Port A multiplexes AD0-AD7, Port C drives A8-A15, and ALE latches the low address into a 74HC573 transparent latch, while dedicated /RD and /WR strobes provide zero-glue-logic timing at 16 MHz. A typical logger attaches a 32 KB or 64 KB SRAM such as the 62256/628128 family, buffers sensor samples from an SPI ADC, then periodically flushes blocks to EEPROM or a UART host. This architecture delivers kilobytes of ring-buffer capacity that comparable 8-pin-to-40-pin AVRs without XMEM cannot match, making the 8515 uniquely efficient for buffered measurement tasks.
Recommended
Motor Control and Relay Sequencing Panels
The ATMEGA8515-16PJ provides two flexible Timer/Counters with compare modes plus an 8-bit Timer0 with the OC0 PWM output, enabling low-resolution PWM drive for DC motor speed control and servo positioning without external PWM ICs. At 16 MHz, an 8-bit PWM at several kHz is achievable, adequate for relay sequencing, valve control, and brushed-motor applications. The 35 GPIO lines allow direct driving of transistor stages for multiple relays, with the external interrupt sources providing position or limit-switch feedback. In retrofit panels using 8051-style layouts, the 8515's footprint-compatible port arrangement minimizes trace rework. Designers should budget the 512 B SRAM carefully, keeping state machines lean, or extend RAM via the XMEM interface for larger sequencing tables and event histories.
Recommended
Educational and Hobbyist Embedded Platforms
The ATMEGA8515-16PJ remains popular in education because its 40-pin PDIP package is socketable, easily replaced after wiring mistakes, and breadboard-adjacent for trainer boards. Its AVR RISC core executes most of its 130 instructions in a single clock cycle, giving students predictable timing for assembly-language exercises, while 32 working registers simplify C development with avr-gcc. The rich peripheral set - UART for PC communication, SPI for SD cards and displays, timers with PWM, and external interrupts - covers a complete embedded curriculum. The 8 KB Flash is programmed in-system through the SPI header, so no chip removal is needed between lab sessions. Universities maintaining 8051-era trainer hardware can often adopt the 8515 without replacing the board skeleton, protecting laboratory investment.
Recommended
Test Jigs and Bench Instrumentation
Production test jigs benefit from the ATMEGA8515-16PJ's combination of deterministic single-cycle AVR execution, 16 MIPS throughput, and 35 I/O lines able to bit-bang legacy interfaces such as I2C-adjacent two-wire protocols, one-wire devices, and parallel buses. The XMEM interface can attach 64 KB of fast SRAM to capture high-rate parallel port traces from the device under test, which few 8-bit MCUs in through-hole packages can do. UART output streams results to a PC while SPI talks to DACs for stimulus generation. The socketed PDIP format means a damaged jig controller can be swapped in seconds on the production floor, minimizing downtime. Firmware stored in the self-programmable Flash supports field re-qualification of jigs for new product variants without hardware changes.
Recommended
Embedded Communication Nodes (UART/SPI)
The ATMEGA8515-16PJ serves as a protocol converter or communication node using its hardware UART (PD0/RXD, PD1/TXD) and SPI master/slave port (PB5-PB7 with PB0/SS). A common topology receives RS-232/RS-485 framing via the UART, processes it in the 16 MIPS core, and relays it over SPI to displays, EEPROM, or RF modules. The external interrupt sources (INT0, INT1 on PD2/PD3) timestamp asynchronous events, while the XMEM buffer stores frames beyond the 512 B internal SRAM limit. At 16 MHz the UART supports typical industrial baud rates with margin for service routines. For battery-independent nodes the through-hole PDIP allows robust soldered or socketed mounting in metal cabinets, and the mature Microchip supply chain, verified as of 2026-09-18, supports multi-year production programs.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8515-16PJ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8515-16PU | ATMEGA8515-16PI | ATMEGA8515-16AUR | ATMEGA8-16PI | ATMEGA16-16PU |
|---|---|---|---|---|---|---|
| Package | 40-PDIP | 40-PDIP - same | 40-PDIP - same | TQFP-44 - different package | 40-PDIP - same package, different pinout | 40-PDIP - same package, different pinout |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| Flash Memory | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 16 KB |
| SRAM | 512 B | 512 B | 512 B | 512 B | 1 KB | 1 KB |
| External Memory Interface | Yes, up to 64 KB | Yes, up to 64 KB | Yes, up to 64 KB | Yes, up to 64 KB | No | Yes, up to 64 KB |
| Lead Finish / RoHS | Lead-bearing (PJ suffix) | Lead-free, RoHS compliant | Lead-free, RoHS compliant | Lead-free, RoHS compliant | Lead-free, RoHS compliant | Lead-free, RoHS compliant |
| Temperature Grade | Commercial | Commercial/lead-free | Industrial | Industrial | Industrial | Commercial |
| Firmware Compatibility | Reference (ATmega8515 family) | 100% - same die | 100% - same die | 100% - same die | No - different register map | No - different register map |
Key Differentiators
- External memory interface up to 64 KB (vs ATMEGA8-16PI)
- 8051-compatible DIP-40 footprint (vs ATMEGA16-16PU)
- Identical-die lead-free upgrade path (vs ATMEGA8515-16PU)
Design Notes
The internal SRAM is only 512 bytes. Deep call stacks, large buffers, or string-heavy code will overflow silently and corrupt variables. Estimated: with 130 instructions and a C compiler, reserve roughly 100-150 bytes for stack and register saves; keep statically allocated buffers under ~300 bytes or move them to external SRAM via the XMEM interface. Enabling XMEM consumes Port A and Port C, so plan remaining GPIO (about 19 free lines) before committing to external RAM in your PCB layout.
For the XMEM bus, keep ALE-to-latch (74HC573) and SRAM address/data traces under 10 cm and route the AD0-AD7 bus away from the XTAL circuit. Estimated: at 16 MHz, bus setup times in the datasheet allow the 74HC573 latch comfortably, but added trace capacitance above ~30 pF per line erodes margin. Place 100 nF decoupling directly across VCC (pin 40) and GND (pin 20) plus one bulk 10 uF per board. RESET (pin 9) benefits from a 10 k pull-up for reliable ISP programming.
Verify the supply voltage window for the -16 speed grade against the electrical characteristics section of the Microchip datasheet (document 2512S) before powering from a 3.3 V rail; the 16 MHz grade is typically specified for the 5 V range, and 3.3 V operation may require a lower speed grade (-8) or derating. Brown-out detection should be enabled via fuse bits to prevent EEPROM corruption during power-down - a well-documented AVR failure mode in industrial environments with noisy supplies.
Compliance Information
The PJ suffix denotes a lead-bearing plating finish; the PU suffix variant is the lead-free RoHS-compliant equivalent of the same die. RoHS/REACH status for this exact MPN was not stated in the verified web data and should be confirmed via the Microchip product page.
