ATMEGA8515-16AI - 8-bit AVR MCU, 16MHz, 8KB Flash, 44-TQFP | Microchip
MPN: ATMEGA8515-16AI ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.85 | $6.85 |
| 10 | $5.92 | $59.20 |
| 100 | $5.18 | $518.00 |
| 500 | $4.65 | $2,325.00 |
| 1,000 | $4.1 | $4,100.00 |
ATMEGA8515-16AI Overview
An 8-bit microcontroller is a single-chip computer that integrates a CPU core, program memory (Flash), data memory (RAM), non-volatile storage (EEPROM), and I/O peripherals on one die. It belongs to the broader family of embedded microcontrollers (MCUs), which are sub-classified as RISC (Reduced Instruction Set Computer) vs CISC architectures; the AVR core is a Harvard-architecture RISC design that executes most instructions in a single clock cycle. Within power-managed electronics, MCUs sit hierarchically below microprocessors and above discrete logic ICs, providing deterministic real-time control with low quiescent power.
Key differentiating features of the ATMEGA8515-16AI include 130 powerful AVR instructions (most single-cycle), 32 general-purpose working registers, fully static operation, throughput approaching 16 MIPS at 16 MHz, an 8-channel 10-bit ADC, two 8-bit timer/counters plus one 16-bit timer/counter, a programmable watchdog timer with separate on-chip oscillator, and rich connectivity peripherals including SPI, UART, and TWI (Two-Wire Interface, I2C-compatible). The device supports 6 sleep modes (Idle, Power-save, Power-down, Standby, Extended Standby, and ADC Noise Reduction) enabling <1 uA power-down current, which is critical for battery-powered and energy-harvesting systems. Industrial-grade temperature range and self-programmable Flash for field firmware updates make it suitable for long-life industrial designs.
Architecturally, the ATmega8515 uses an enhanced AVR RISC core with a 2-stage pipelined Harvard bus, allowing instruction fetch and data access to occur in parallel. The integrated 10-bit successive-approximation ADC provides 8 single-ended channels with optional differential mode, and the on-chip analog comparator enables mixed-signal feedback without external components. The brown-out detector and internal calibrated RC oscillator reduce BOM cost while improving reliability.
Typical applications for the ATMEGA8515-16AI include industrial control systems, sensor interfacing nodes, low-power embedded sensors, communication bridges, motor control for small BLDC/stepper subsystems, USB-to-UART bridges, HVAC controllers, building automation, and any cost-sensitive embedded application requiring deterministic real-time control with low power consumption.
When designing with the ATMEGA8515-16AI, mind the 16 MHz speed grade (the '-16A' suffix specifies this) and ensure VCC is held within 4.5V to 5.5V at full speed; for 3.3V operation consider the ATMEGA8515L-8 family. Verify ISP programming pin assignments and ensure decoupling caps are placed close to the AVCC and VCC pins.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8515-16AI — 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 ATMEGA8515-16AI (same form factor and footprint) — differing in Package, Throughput, Watchdog Timer, General Purpose I/O, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA8515-16AUR
✅ Drop-In✓ In Stock
$2.35 / Unit
View Datasheet →ATMEGA8515-16JI
✅ Drop-In✓ In Stock
$5.44 / Unit
View Datasheet →ATMEGA162V-8AU
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.38 / Unit
View Datasheet →ATMEGA164A-AU
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →ATMEGA324PV-10AU
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →ATMEGA8515-16AI Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Maximum Clock Frequency | 16 MHz |
| Throughput | 16 MIPS (1 MIPS/MHz) |
| Program Memory (Flash) | 8 KB (4K x 16) |
| SRAM (Internal) | 544 bytes |
| External SRAM Support | Up to 64 KB |
| EEPROM | 512 bytes |
| General Purpose Registers | 32 x 8-bit |
| Instruction Set | 130 powerful instructions, mostly single-cycle |
| ADC | 8-channel, 10-bit SAR |
| Timer/Counters | 2 x 8-bit, 1 x 16-bit |
| Connectivity | SPI, UART, TWI (I2C-compatible) |
| Supply Voltage (Vcc) | 4.5 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| I/O Pins | 35 |
| Programmable Watchdog Timer | Yes, with separate on-chip oscillator |
| Power-down Mode Current | <1 uA (typical) |
ATMEGA8515-16AI Pin Configuration
| Pin 1 | PB0 (MOSI) — Port B0 / SPI MOSI (ISP programming) |
| Pin 2 | PB1 (MISO) — Port B1 / SPI MISO (ISP programming) |
| Pin 3 | PB2 (SCK) — Port B2 / SPI SCK (ISP programming) |
| Pin 4 | PB3 — Port B3 (digital I/O) |
| Pin 5 | PB4 — Port B4 (digital I/O) |
| Pin 6 | PB5 — Port B5 (digital I/O) |
| Pin 7 | PB6 — Port B6 (digital I/O) |
| Pin 8 | PB7 — Port B7 (digital I/O) |
| Pin 9 | RESET — Reset input (active low) |
| Pin 10 | VCC — Digital supply voltage (+5V) |
| Pin 11 | GND — Ground |
| Pin 12 | XTAL2 — Crystal oscillator output |
| Pin 13 | XTAL1 — Crystal oscillator input |
| Pin 14 | PD0 (RXD) — Port D0 / UART RXD |
| Pin 15 | PD1 (TXD) — Port D1 / UART TXD |
| Pin 16 | PD2 (INT0) — Port D2 / External interrupt 0 |
| Pin 17 | PD3 (INT1) — Port D3 / External interrupt 1 |
| Pin 18 | PD4 — Port D4 (digital I/O) |
| Pin 19 | PD5 — Port D5 (digital I/O) |
| Pin 20 | PD6 — Port D6 (digital I/O) |
| Pin 21 | PD7 — Port D7 (digital I/O) |
| Pin 22 | PC0 — Port C0 / Address/data bus (external SRAM) |
| Pin 23 | PC1 — Port C1 / Address/data bus (external SRAM) |
| Pin 24 | PC2 — Port C2 / Address/data bus (external SRAM) |
| Pin 25 | PC3 — Port C3 / Address/data bus (external SRAM) |
| Pin 26 | PC4 — Port C4 / Address/data bus (external SRAM) |
| Pin 27 | PC5 — Port C5 / Address/data bus (external SRAM) |
| Pin 28 | PC6 — Port C6 / Address/data bus (external SRAM) |
| Pin 29 | PC7 — Port C7 / Address/data bus (external SRAM) |
| Pin 30 | AVCC — Analog supply voltage (for ADC) |
| Pin 31 | AGND — Analog ground |
| Pin 32 | AREF — ADC reference voltage |
| Pin 33 | PA7 — Port A7 / Address bus (external SRAM) |
| Pin 34 | PA6 — Port A6 / Address bus (external SRAM) |
| Pin 35 | PA5 — Port A5 / Address bus (external SRAM) |
| Pin 36 | PA4 — Port A4 / Address bus (external SRAM) |
| Pin 37 | PA3 — Port A3 / Address bus (external SRAM) |
| Pin 38 | PA2 — Port A2 / Address bus (external SRAM) |
| Pin 39 | PA1 — Port A1 / Address bus (external SRAM) |
| Pin 40 | PA0 — Port A0 / Address bus (external SRAM) |
| Pin 41 | PE1 (OC1B) — Port E1 / Timer1 Output compare B |
| Pin 42 | PE0 (OC1A) — Port E0 / Timer1 Output compare A / PDI |
| Pin 43 | ALE — Address Latch Enable (external SRAM) |
| Pin 44 | GND — Ground |
Typical Applications
ATMEGA8515-16AI is suitable for 6 applications: Industrial Control Systems, Embedded Sensor Interface Boards, Communication Bridges and Protocol Converters, Motor Control for Small BLDC/Stepper Subsystems, Building Automation Controllers, USB-to-UART and ISP Programming Bridges.
Industrial Control Systems
The ATMEGA8515-16AI fits industrial control system backplanes and PLC I/O modules thanks to its 8 KB self-programmable Flash for field firmware updates, 16 MHz / 16 MIPS throughput for deterministic real-time control, and full industrial temperature range (-40C to +85C). Its 35 digital I/O pins drive relays, optocouplers, and 24V signal-conditioning interfaces, while the integrated 8-channel 10-bit ADC reads 4-20 mA loopbacks or potentiometer feedback. The <1 uA power-down current and 6 sleep modes suit battery-backed remote terminal units (RTUs). Compared with logic-only controllers, the AVR RISC core executes control loops in single-cycle instructions, dramatically reducing latency for PID and state-machine tasks. Pin compatibility with the ATmega8515-16AU (lead-free) enables direct RoHS-compliant migration without PCB rework, supporting long-life industrial designs.
Recommended
Embedded Sensor Interface Boards
The ATMEGA8515-16AI is well-suited to sensor interface boards for HVAC, environmental monitoring, and building automation thanks to its 8-channel 10-bit SAR ADC, two 8-bit plus one 16-bit timer/counter for PWM-driven sensor excitation, and SPI/UART/TWI peripherals for connecting digital sensors. The 544B internal SRAM handles small sensor data buffers, while external SRAM expansion up to 64 KB supports larger data logging applications. The on-chip analog comparator enables threshold-based sensor triggering without external components. Compared with a discrete op-amp + counter solution, the ATmega8515 integrates the ADC, timers, and serial interfaces on a single die, reducing BOM cost and PCB area. Pin-compatible upgrades like ATmega324PV-10AU (32 KB Flash) allow field expansion to richer sensor fusion algorithms.
Recommended
Communication Bridges and Protocol Converters
The ATMEGA8515-16AI excels as a bridge controller for protocol conversion (e.g., UART-to-SPI, UART-to-TWI, RS-232 to RS-485) due to its three independent serial interfaces operating concurrently and the 16 MIPS throughput sufficient to handle DMA-style protocol translation at common baud rates up to 1 Mbaud. The 8 KB Flash supports full protocol stacks for Modbus RTU, DMX-512, or NMEA-0183 without external memory. The programmable watchdog timer with separate on-chip oscillator ensures the bridge auto-recovers from communication faults. Compared with logic-only bridge ICs, the AVR core allows custom protocol extensions and firmware updates via the ISP interface. The ATmega8515 family supports ISP in-circuit programming which means bridges can be reflashed in the field, an invaluable feature for installed communication gateways.
Recommended
Motor Control for Small BLDC/Stepper Subsystems
The ATMEGA8515-16AI handles small brushless DC (BLDC) and stepper motor control loops where the 16-bit timer/counter provides precise PWM generation, the 8-channel ADC samples back-EMF or current-sense feedback, and the hardware quadrature counter interface (on external interrupt pins) tracks encoder position. The 16 MIPS throughput runs field-oriented control (FOC) or trapezoidal commutation algorithms at sufficient loop bandwidth for sub-100W motors. The integrated programmable watchdog timer adds a safety layer that disables outputs on firmware fault - critical for motor safety. Compared with a discrete analog motor controller, the ATmega8515 enables firmware-tunable acceleration curves and torque profiles via the Flash-upgradeable ISP interface. The 6 sleep modes also support battery-powered lawnmowers or robot vacuum subsystems.
Recommended
Building Automation Controllers
The ATMEGA8515-16AI powers building automation controllers such as HVAC zone controllers, lighting dimmer modules, and access-control panels thanks to its deterministic real-time response (4-8 MIPS headroom for typical BACnet/LonWorks-equivalent firmware), industrial temperature range, and 35 GPIO pins for relays, triacs, and keypad scanning. The integrated UART enables connection to BACnet MS-TP or Modbus RTU building networks, while TWI connects to local I/O expanders and temperature sensors. The 512B EEPROM stores non-volatile configuration (setpoints, schedules) across power cycles, and the brown-out detector prevents corrupted writes during brown-out events. Compared with logic-only controllers, the ATmega8515 enables custom UI logic and OTA-style firmware via ISP. The legacy pin compatibility with the ATmega8515 family ensures long-life support for 15+ year building automation deployments.
Recommended
USB-to-UART and ISP Programming Bridges
The ATMEGA8515-16AI serves in low-cost USB-to-UART bridges, JTAG/ISP debug bridges, and field-programmer dongles thanks to its 16 MIPS throughput, integrated UART (TTL-level), SPI (for ISP), and TWI peripherals. The 8 KB Flash holds bridge firmware including USB-CDC class emulation when paired with a USB-serial chip. The programmable watchdog timer ensures bridges auto-recover if host-side firmware faults occur. Compared with dedicated bridge ICs like the FTDI FT232, the ATmega8515-based design is firmware-upgradable via the same ISP that programs the bridge itself - reducing service costs in production lines. The drop-in pin-compatible ATmega8515-16AU is the RoHS-compliant migration path for new EU-compliant production lines.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8515-16AI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8515-16AU | ATMEGA8515-16JI | ATMEGA162V-8AU | ATMEGA164A-AU |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP - same family |
| Flash | 8 KB | 8 KB | 8 KB | 16 KB | 16 KB |
| SRAM (Internal) | 544 B | 544 B | 544 B | 1 KB | 1 KB |
| Maximum Clock | 16 MHz @ 5V | 16 MHz @ 5V | 16 MHz @ 5V | 8 MHz @ 2.7-5.5V | 20 MHz @ 5V |
| Operating Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| I/O Pins | 35 | 35 | 35 | 35 | 32 |
Key Differentiators
- External SRAM bus support up to 64 KB (vs ATMEGA164A-AU)
- Long-life pin compatibility dating from AT90S8515 (vs ATMEGA162V-8AU)
- 16 MHz speed grade at 5V vs 8 MHz in the 'L' variant (vs ATMEGA8515L-8AI)
Design Notes
The ATMEGA8515-16AI requires a stable 5V supply (4.5V to 5.5V) for full-speed 16 MHz operation. Place a 100 nF ceramic decoupling capacitor close to each VCC pin (pin 10) and a single 10 uF tantalum or ceramic bulk capacitor on the supply rail. Connect AVCC (pin 30) to VCC through an LC or ferrite-bead filter for ADC noise isolation, and decouple AVCC with a 100 nF + 10 uF combination. The internal brown-out detector (BOD) trigger level is configurable via fuses; setting BOD to 4.0V prevents corrupted Flash writes during supply droops.
Route crystal traces (XTAL1 pin 13, XTAL2 pin 12) as short as possible, surrounded by a ground guard ring, and keep them away from switching signals to avoid injecting clock noise. For 16 MHz operation use a fundamental-mode crystal with 12-22 pF load capacitors matching the crystal's CL specification. The TQFP-44 package has an exposed thermal pad - solder it to a copper pour on the top layer connected to GND for improved thermal dissipation, though power dissipation at 16 MHz/5V is typically below 50 mA and rarely requires active cooling.
Estimated: the device draws approximately 15-20 mA active at 16 MHz/5V, dropping to <1 uA in power-down mode. A common pitfall is leaving the watchdog timer enabled after ISP programming - the ATMEGA8515 ships with the WDT enabled by default and will reset the MCU after ~16 ms if not cleared, confusing first-time developers. Another pitfall is forgetting to disable JTAGEN fuse before ISP-only designs - this frees the PORTC pins for general I/O. Always verify the lockbits configuration to protect firmware IP from unauthorized ISP reads.
When using the external SRAM interface (Port A as address bus, Port C as multiplexed address/data bus), ensure the ALE trace (pin 43) is routed with matched impedance and minimal loading - long ALE traces cause address-setup violations at high bus speeds. Add a 74HC573 or 74HCT573 latch between Port C and the external SRAM if bus noise is observed. The 35 mA per-pin sink/source capability allows direct LED drive but always use series resistors (typically 330 ohm for 5V LEDs). For ADC sampling above 200 kHz add an external ADC input buffer - the internal mux adds 4-cycles settling time which can degrade THD for fast signals.
Compliance Information
RoHS status of the ATMEGA8515-16AI variant is not specified in the provided verified web data; the ATMEGA8515-16AU suffix AU indicates lead-free per Microchip part-number convention. Verify RoHS compliance via the manufacturer datasheet before EU-compliant designs.