ATMEGA8515-16MJ - 8KB Flash 16MHz AVR MCU | Microchip
MPN: ATMEGA8515-16MJ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.27 | $3.27 |
| 10 | $3.02 | $30.20 |
| 100 | $2.78 | $278.00 |
| 500 | $2.55 | $1,275.00 |
| 1,000 | $2.34 | $2,340.00 |
ATMEGA8515-16MJ Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor in the broader hierarchy of embedded MCUs: microcontroller -> embedded processor -> integrated circuit. The AVR family executes most instructions in a single clock cycle, and the ATmega8515 adds a key differentiator within the family: a full external memory interface supporting up to 64 KB of external SRAM, addressing applications whose code or data needs exceed on-chip resources.
Key features include 35 general purpose I/O lines, 32 general purpose working registers, two flexible Timer/Counters with compare modes, internal and external interrupt sources, a programmable serial USART, and a programmable Watchdog Timer with on-chip oscillator. The 16 MJ suffix indicates the 4.5V to 5.5V operating voltage range, 16 MHz speed grade, and lead-free MLF/VQFN package with exposed pad for improved ground and thermal performance.
Architecturally, the device combines Read-While-Write Flash programming with a rich peripheral set in a low-power CMOS process. In-system programmability allows firmware updates on the assembled PCB via SPI, reducing field-service cost. The external memory interface maps external SRAM into the data address space transparently.
Typical applications include industrial control panels, motor-adjacent control logic, legacy AVR design maintenance, and communication subsystems that benefit from the USART plus abundant GPIO.
Design consideration: at 16 MHz and 5V, observe the AVR maximum frequency versus VCC curve; below 4.5V the 16 MHz grade is not guaranteed.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8515-16MJ — 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 ATMEGA8515-16MJ (same form factor and footprint) — differing in Package, External Memory Interface, Throughput, Core Architecture, Instruction Set.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8515-16MU
✅ Drop-In✓ In Stock
$2.12 / Unit
View Datasheet →ATMEGA8515-16MUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.85 / Unit
View Datasheet →ATMEGA8515L-8MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.54 / Unit
View Datasheet →ATMEGA162-16MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.19 / Unit
View Datasheet →ATMEGA8515-16JI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.44 / Unit
View Datasheet →ATMEGA8515-16MJ Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC (Harvard) |
| Flash Program Memory | 8 KB (In-System Programmable) |
| SRAM | 512 bytes |
| EEPROM | 512 bytes |
| External Memory Interface | Up to 64 KB external SRAM |
| Max Clock Frequency | 16 MHz |
| Throughput | 16 MIPS at 16 MHz |
| Operating Voltage | 4.5 V to 5.5 V |
| General Purpose I/O | 35 lines |
| Working Registers | 32 x 8-bit |
| Timers | Two Timer/Counters with compare modes |
| Serial Interfaces | Programmable serial USART |
| Watchdog Timer | Programmable, with on-chip oscillator |
| Interrupts | Internal and external interrupt sources |
| Package | 44-VFQFN exposed pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATMEGA8515-16MJ 44-vfqfn exposed pad Pin Configuration Guide
Pin configuration for ATMEGA8515-16MJ (44-vfqfn exposed pad 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 ATMEGA8515-16MJ.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA8515-16MJ is suitable for 6 applications: Industrial Control Panels, External-Memory Data Buffers, Legacy AVR Design Maintenance, Serial Communication Nodes, Motor and Actuator Control, Educational and Hobbyist AVR Systems.
Industrial Control Panels
The ATMEGA8515-16MJ fits industrial control panels where 35 GPIO lines, two Timer/Counters with compare modes, and 5V noise-tolerant logic are required. The external memory interface supports up to 64 KB of external SRAM for recipe tables or HMI buffers that exceed the 512-byte internal SRAM, while the programmable Watchdog Timer with its own on-chip oscillator recovers the system from firmware lockups without external components. Operating at 16 MIPS, the MCU scans inputs, drives relays via timer compare outputs, and communicates over the serial USART to SCADA converters. The 44-VFQFN exposed pad soldered to ground plane improves EMI behavior in electrically noisy cabinets.
Recommended
External-Memory Data Buffers
Designs requiring working memory beyond the 512-byte internal SRAM use the ATMEGA8515-16MJ external memory interface, which transparently maps up to 64 KB of external SRAM into the data address space using port A as the multiplexed address/data bus and port C for address latching. Typical circuits pair the MCU with a standard 64 KB SRAM such as the CY62256 class device and a 74HC573 latch. The 16 MHz clock supports fast external bus cycles, and Read-While-Write Flash lets the firmware log to external RAM while executing from the 8 KB program memory without stalls.
Recommended
Legacy AVR Design Maintenance
The ATMEGA8515-16MJ is the natural sourcing choice for sustaining existing ATmega8515-based products, since the die, firmware, and 44-pad VQFN land pattern carry over unchanged. In-System Programming via SPI allows field firmware updates without desoldering, and the 512-byte EEPROM retains calibration data across power cycles. When -16MJ lead times stretch, the drop-in ATMEGA8515-16MU or tape-and-reel -16MUR keeps production running with zero redesign. For designs outgrowing 8 KB, the pin-compatible ATMEGA162-16MU doubles Flash on the same PCB.
Recommended
Serial Communication Nodes
With a full programmable serial USART plus abundant GPIO, the ATMEGA8515-16MJ serves as a protocol converter or remote I/O node on RS-232/RS-485 networks. The USART runs reliably from a crystal at standard baud rates at the 16 MHz clock, while external interrupts respond to bus activity with microsecond latency. The 5V supply (4.5V to 5.5V) directly interfaces classic 5V transceivers without level shifting. On-chip EEPROM stores node addresses, and the Watchdog Timer ensures automatic recovery if bus lockups stall the firmware.
Recommended
Motor and Actuator Control
Two Timer/Counters with compare modes generate PWM outputs for DC motor speed control and servo positioning directly from the ATMEGA8515-16MJ, eliminating external PWM ICs. At 16 MIPS, the control loop executes proportional-integral algorithms each PWM period with headroom. The 5V GPIO can drive logic-level MOSFET gate drivers, and timer input-capture style interrupt pins measure encoder feedback. For bench and prototype builds, the TQFP-packaged ATMEGA8515-16JI on adapter boards eases probing; production uses the same die in the exposed-pad VQFN.
Recommended
Educational and Hobbyist AVR Systems
The ATmega8515 remains popular in education and the maker community, supported by community toolchains such as the MajorCore Arduino hardware package on GitHub, which brings Arduino-core development to the ATmega8515 and ATmega162. The external memory interface is a teaching asset, demonstrating real bus architectures with latches and SRAM that newer single-chip MCUs hide. In-System Programming over SPI with low-cost ISP programmers makes lab use inexpensive, and the 35 GPIO lines support rich breadboard-through-adapter experimentation at 16 MIPS performance.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8515-16MJ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8515-16MU | ATMEGA8515-16MUR | ATMEGA162-16MU |
|---|---|---|---|---|
| Package | 44-VFQFN exposed pad | 44-VFQFN exposed pad - same | 44-VFQFN exposed pad - same | 44-VFQFN exposed pad - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 8 KB | 8 KB | 8 KB | 16 KB |
| SRAM | 512 bytes | 512 bytes | 512 bytes | 1 KB |
| Max Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| Operating Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| External Memory Interface | Up to 64 KB | Up to 64 KB | Up to 64 KB | Up to 64 KB |
| Packaging Option | Tray | Tray | Tape & Reel | Tray |
Key Differentiators
- External memory interface up to 64 KB (vs ATMEGA8-16PI)
- Same die, supply-chain flexibility (vs ATMEGA8515-16MU)
- Flash growth path on the same PCB (vs ATMEGA162-16MU)
- Honest limitation: 5V-only operation (vs ATMEGA8515L-8MU)
Design Notes
The ATMEGA8515-16MJ is a 5V-only part: the -16 speed grade requires 4.5V to 5.5V VCC for the full 16 MHz rating. Regulate with a 5V LDO or buck rated for at least 30 mA plus I/O load. Per the AVR maximum frequency versus VCC curve in the Microchip datasheet, clocking at 16 MHz below 4.5V is out of specification; if your rail can sag (for example 5V logic with long cable drops), either tighten regulation or drop to the L-8MU 8 MHz grade. Decouple VCC with 100 nF ceramic at each supply pad plus 10 uF bulk near the exposed pad.
The 44-VFQFN exposed pad is the primary ground connection and must be soldered to the PCB ground plane, not left floating. Use an array of thermal vias under the pad (typically 4 to 9, filled or plugged) to anchor ground and dissipate package heat. Land-pattern stencil design should use segmented apertures (roughly 60 to 70 percent coverage) to prevent solder voiding and die-tilt during reflow. Pad 1 orientation follows the datasheet package drawing dot; verify with your footprint library before release.
When the external memory interface is enabled, port A carries the multiplexed address/data bus and port C drives address lines to the external SRAM. Keep the 74HC573 latch and SRAM within a few centimeters of the MCU, with series termination (22 to 33 ohm) on fast address lines to control ringing at 16 MHz. Route the 8-bit bus on the same layer as a contiguous ground reference. If the external bus is unused, configure those pins as GPIO and pull unused inputs to a defined level to avoid floating-input current.
Three recurring mistakes with the ATmega8515: (1) forgetting the SPIEN fuse and locking out In-System Programming, which then requires high-voltage parallel programming to recover; (2) omitting the Watchdog period calibration after changing CKSEL fuses, causing spurious resets; (3) assuming the 16 MHz grade works at 3.3V - it does not, and the L grade with its 8 MHz limit must be selected instead. Always recompile and re-verify fuse settings when substituting ATMEGA162 for the 8515, since register maps differ slightly.
Compliance Information
The J package suffix denotes Microchip lead-free/RoHS-compliant packaging. REACH, halogen-free, and conflict-minerals status not stated in provided data.
