ATMEGA16L-8AJ - 8MHz 16KB Flash AVR MCU 44-TQFP | Microchip
MPN: ATMEGA16L-8AJ β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.2 | $3.20 |
| 10 | $2.86 | $28.60 |
| 100 | $2.45 | $245.00 |
| 500 | $2.1 | $1,050.00 |
| 1,000 | $1.82 | $1,820.00 |
ATMEGA16L-8AJ Overview
An 8-bit microcontroller is a single-chip computer that integrates a CPU core, program memory, data memory, and peripherals onto one die. Within the power-management hierarchy of embedded systems, the AVR ATmega family sits in the general-purpose MCU class, part of the broader microcontroller unit (MCU) -> integrated circuit -> semiconductor taxonomy. The AVR architecture uses an advanced RISC core with 131 powerful instructions, most of which execute in a single clock cycle, delivering up to 16 MIPS throughput at 16MHz and up to 8 MIPS at the 8MHz rating of this L-variant.
Key features include an 8-channel, 10-bit analog-to-digital converter (ADC), a JTAG interface for on-chip debugging, two 8-bit and one 16-bit timers/counters with PWM outputs, an 8-bit synchronous and asynchronous USART, Master/Slave SPI, and a Two-Wire Interface (TWI / I2C). The ATMEGA16L-8AJ is the low-voltage L-grade part, specified for operation from approximately 2.7V to 5.5V at up to 8MHz over the industrial temperature range, making it suitable for 3.3V battery-powered designs as well as 5V legacy rails.
Technically, the device combines a Harvard-architecture RISC core with fast-register access, in-system self-programmable Flash, and internal RC oscillator options. Brown-out reset, watchdog timer, and an on-chip debug channel via JTAG provide robust field operation and development support without external debug silicon.
Typical applications include industrial control panels, sensor nodes, embedded metering, HVAC controllers, motor control peripherals, and educational/hobby platforms where proven 8-bit performance is required.
Designers should note that Flash endurance and boot-loader self-programming enable field firmware updates; reserve a boot sector and include a brown-out detector configuration appropriate to the supply rail.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found on the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA16L-8AJ 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 ATMEGA16L-8AJ (same form factor and footprint) β differing in Flash Program Memory, Package, SRAM, Instruction Set, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA16A-AU
β Drop-Inβ In Stock
$2.05 / Unit
View Datasheet βATMEGA32A-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA16L-8AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA16-16AJ
β Drop-Inβ In Stock
$2.1 / Unit
View Datasheet βATMEGA162-16AJ
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA16L-8AJ Maximum Ratings & Electrical Characteristics
| Core Processor | AVR (8-bit RISC) |
| Core Size | 8-bit |
| Speed | 8MHz |
| Flash Program Memory | 16KB (8K x 16) |
| SRAM | 1KB |
| EEPROM | 512 Bytes |
| Number of I/O | 32 |
| ADC Resolution | 10-bit |
| ADC Channels | 8 |
| UART/USART | 1 (USART) |
| SPI | 1 |
| TWI (I2C) | 1 |
| JTAG | Yes (on-chip debug) |
| Timers/Counters | 2 x 8-bit, 1 x 16-bit |
| PWM Channels | 4 |
| Operating Supply Voltage | 2.7 V to 5.5 V (L-grade) |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 44-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Instruction Set | 131 instructions, most single-cycle |
ATMEGA16L-8AJ Pin Configuration
| Pin 1 | PA0 (ADC0) β Port A bit 0 / ADC channel 0 |
| Pin 2 | PA1 (ADC1) β Port A bit 1 / ADC channel 1 |
| Pin 3 | PA2 (ADC2) β Port A bit 2 / ADC channel 2 |
| Pin 4 | PA3 (ADC3) β Port A bit 3 / ADC channel 3 |
| Pin 5 | PA4 (ADC4) β Port A bit 4 / ADC channel 4 |
| Pin 6 | PA5 (ADC5) β Port A bit 5 / ADC channel 5 |
| Pin 7 | PA6 (ADC6) β Port A bit 6 / ADC channel 6 |
| Pin 8 | PA7 (ADC7) β Port A bit 7 / ADC channel 7 |
| Pin 9 | VCC β Digital supply voltage |
| Pin 10 | GND β Ground |
| Pin 11 | PB0 (XCK/T0) β Port B bit 0 / USART external clock / Timer0 counter input |
| Pin 12 | PB1 (T1) β Port B bit 1 / Timer1 counter input |
| Pin 13 | PB2 (AIN0/INT2) β Port B bit 2 / Analog comparator input 0 / External interrupt 2 |
| Pin 14 | PB3 (AIN1/OC0) β Port B bit 3 / Analog comparator input 1 / Timer0 PWM output |
| Pin 15 | PB4 (SS) β Port B bit 4 / SPI slave select |
| Pin 16 | PB5 (MOSI) β Port B bit 5 / SPI master data output |
| Pin 17 | PB6 (MISO) β Port B bit 6 / SPI master data input |
| Pin 18 | PB7 (SCK) β Port B bit 7 / SPI serial clock |
| Pin 19 | PC0 (SCL) β Port C bit 0 / TWI serial clock |
| Pin 20 | PC1 (SDA) β Port C bit 1 / TWI serial data |
| Pin 21 | PC2 (TCK) β Port C bit 2 / JTAG test clock |
| Pin 22 | PC3 (TMS) β Port C bit 3 / JTAG test mode select |
| Pin 23 | PC4 (TDO) β Port C bit 4 / JTAG test data output |
| Pin 25 | PC6 (TOSC1) β Port C bit 6 / Timer oscillator input |
| Pin 26 | PC7 (TOSC2) β Port C bit 7 / Timer oscillator output |
| Pin 27 | AREF β ADC analog reference |
| Pin 28 | AGND β Analog ground |
| Pin 29 | AVCC β ADC supply voltage |
| Pin 30 | PD0 (RXD) β Port D bit 0 / USART receive |
| Pin 31 | PD1 (TXD) β Port D bit 1 / USART transmit |
| Pin 32 | PD2 (INT0) β Port D bit 2 / External interrupt 0 |
| Pin 33 | PD3 (INT1) β Port D bit 3 / External interrupt 1 |
| Pin 34 | PD4 (OC1B) β Port D bit 4 / Timer1 output compare B |
| Pin 35 | PD5 (OC1A) β Port D bit 5 / Timer1 output compare A |
| Pin 36 | PD6 (ICP1) β Port D bit 6 / Timer1 input capture |
| Pin 37 | PD7 (OC2) β Port D bit 7 / Timer2 PWM output |
| Pin 38 | RESET β Active-low reset input |
| Pin 39 | VCC β Digital supply voltage |
| Pin 40 | GND β Ground |
| Pin 41 | XTAL1 β Crystal/oscillator input |
| Pin 42 | XTAL2 β Crystal output |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
ATMEGA16L-8AJ is suitable for 6 applications: Industrial Control Panels, Battery-Powered Sensor Nodes, Embedded Metering and Measurement, Motor Control Peripherals, HVAC and Building Automation, Education and Embedded Development Platforms.
Industrial Control Panels
The ATMEGA16L-8AJ fits industrial control panels because its 5V-tolerant 2.7V-5.5V supply range, -40C to +85C industrial temperature rating, and 32 GPIO lines in a 44-TQFP package cover the typical I/O count of relay- and contactor-driven panels. Its 8-channel 10-bit ADC reads analog sensors such as potentiometers, temperature probes, and 4-20mA-derived signals, while three timers with PWM outputs drive actuators. The brown-out detector and watchdog timer maintain deterministic recovery from supply transients common on factory floors. SPI and TWI interfaces connect displays and EEPROM expansion with only two to four wires. Because the AVR core executes most instructions in a single cycle, scan loops remain predictable without RTOS overhead, reducing firmware complexity in safety-adjacent panel logic.
Recommended
Battery-Powered Sensor Nodes
For battery-powered sensor nodes, the ATMEGA16L-8AJ is attractive because its L-grade supply range (2.7V to 5.5V) allows direct operation from two alkaline cells, three NiMH cells, or a 3.3V lithium rail without a regulator stage. The power-down and power-save sleep modes reduce standby current to microamp levels, while the internal RC oscillator eliminates the quiescent cost of an external crystal in wake-and-measure duty cycles. The 8-channel 10-bit ADC digitizes thermistors, humidity sensors, and light sensors directly, and the TWI bus interfaces digital sensors. Its 512B EEPROM stores calibration coefficients that survive battery replacement. Firmware can use the 16KB self-programmable Flash to implement remote parameter updates over a UART-connected radio module.
Recommended
Embedded Metering and Measurement
Embedded metering products benefit from the ATMEGA16L-8AJ's combination of a 10-bit, 8-channel ADC, a 16-bit timer with input-capture capability for frequency and pulse-width measurement, and 512B of EEPROM for tamper-resistant consumption records. The 16-bit timer/counter1 supports input capture with noise cancellation, enabling energy-pulse counting from utility meters at 8MHz resolution. The JTAG interface allows production-boundary-scan testing of the assembled PCB and on-chip debugging of measurement firmware, cutting qualification time. Self-programmable Flash permits field firmware upgrades for tariff changes without desoldering. Running from an internal reference with the brown-out detector configured, measurements remain valid through supply sags typical of metering environments.
Recommended
Motor Control Peripherals
The ATMEGA16L-8AJ suits low-power motor control peripherals where its four PWM outputs (from the two 8-bit timer/counter0 and 16-bit timer/counter1 units) drive brushed-DC or small stepper motors through external H-bridges. Single-cycle instruction execution enables closed-loop control loops at several kHz sampling rates using the 10-bit ADC for current and position feedback from potentiometers or shunts. The 16-bit timer's input capture reads quadrature or hall-derived feedback for speed regulation. Operating from a 5V rail makes gate-drive interfacing with legacy MOSFET drivers straightforward, while the watchdog timer guarantees safe restart after fault shutdowns. For higher-voltage motors, the MCU only orchestrates; power stage components are external.
Recommended
HVAC and Building Automation
HVAC controllers exploit the ATMEGA16L-8AJ's industrial temperature range (-40C to +85C), its 8-channel 10-bit ADC for temperature, pressure, and humidity sensor aggregation, and TWI/SPI buses for fan controllers and displays. The internal EEPROM stores setpoints and schedules that persist through power outages, while the real-time behavior of the AVR core handles PID control loops for dampers and valve actuators using timer1 PWM outputs. UART connectivity links the controller to RS-485 transceivers for Modbus-style building networks. Self-programmable Flash enables commissioning updates in the field. The 44-TQFP 10x10 mm footprint keeps PCB area compact for thermostat housings, and the 2.7V minimum supply supports backup-battery operation for clock retention.
Recommended
Education and Embedded Development Platforms
The ATMEGA16L-8AJ remains popular in education and development platforms because the AVR architecture is documented thoroughly, the 131-instruction RISC set is learnable, and JTAG on-chip debugging provides a professional toolchain on a low-cost chip. The 16KB self-programmable Flash lets students experiment with boot-loaders, and the full peripheral set (USART, SPI, TWI, ADC, PWM, timers) exercises every common embedded concept on one chip. The 2.7V-5.5V supply range allows safe operation from USB 5V or bench 3.3V sources. Tools such as AVR Studio and the JTAGICE family provide step-debugging, while SPI ISP programmers cost only a few dollars. Its pin-compatible successors (ATMEGA16A-AU) guarantee continued availability for course inventories.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA16L-8AJ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA16A-AU | ATMEGA16L-8AU | ATMEGA16-16AJ | ATMEGA32A-AU | ATMEGA162-16AJ |
|---|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Speed | 8MHz | 16MHz (at 5V) | 8MHz | 16MHz (at 5V) | 16MHz (at 5V) | 16MHz (at 5V) |
| Flash Memory | 16KB | 16KB | 16KB | 16KB | 32KB | 16KB |
| SRAM | 1KB | 1KB | 1KB | 1KB | 2KB | 1KB |
| EEPROM | 512 Bytes | 512 Bytes | 512 Bytes | 512 Bytes | 1KB | 512 Bytes |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V (8MHz grade) | 2.7 V to 5.5 V | 4.5 V to 5.5 V (16MHz full speed) | 2.7 V to 5.5 V (8MHz grade) | 4.5 V to 5.5 V |
| USART Channels | 1 | 1 | 1 | 1 | 1 | 2 |
| ADC | 8-ch, 10-bit | 8-ch, 10-bit | 8-ch, 10-bit | 8-ch, 10-bit | 8-ch, 10-bit | 8-ch, 10-bit |
Key Differentiators
- Low-voltage L-grade operation down to 2.7V at full 8MHz (vs ATMEGA16-16AJ)
- Successor availability with performance headroom (vs ATMEGA16A-AU)
- Memory within the same footprint (vs ATMEGA32A-AU)
- Simplicity vs dual-USART variant (vs ATMEGA162-16AJ)
Design Notes
Decouple both VCC pins (9 and 39) and AVCC (pin 29) with 100nF ceramic capacitors placed within 5 mm of each pin, plus one 10uF bulk capacitor per board. Tie AVCC to VCC through a low-pass LC filter (10uH ferrite + 100nF) when ADC accuracy matters, and connect AGND to a quiet ground point. Configure the brown-out detector (BOD fuse) to a threshold appropriate to your rail - approximately 2.7V BOD for 3.3V systems - to prevent Flash corruption during brown-out events.
Fuse settings are the most common source of field failures on ATmega16 designs. Enabling external crystal clock fuses (CKOPT, SUT/CKSEL) without a valid crystal bricks the device; keep an ISP programmer with a low-frequency rescue clock available. Note that PC2-PC5 default to the JTAG function - to use them as GPIO you must clear the JTAGEN fuse or write the JTD bit in MCUCSR twice within four cycles. Do not run the L-grade part above 8MHz even at 5V; use the ATMEGA16A-AU for 16MHz designs.
Keep the 44-TQFP (10x10 mm) footprint per the manufacturer datasheet land pattern; on a 2-layer board use a solid ground plane under the device. Route the crystal traces (XTAL1/XTAL2, pins 41/42) short (<15 mm) and surround them with ground pour, placing load capacitors within 3 mm of the pins. Keep ADC analog routing (Port A, AREF, AVCC) away from USART and PWM switching lines. Route RESET (pin 38) with a 10k pull-up near the pin and bring it to a programming header for field updates.
Estimated: at 5V, 8MHz with all peripherals active, the ATMEGA16L-8AJ typically draws roughly 10-15 mA (datasheet active-mode current), giving about 50-75 mW dissipation. With a TQFP-44 theta_JA on the order of 60-100 C/W on a standard board, junction rise is only a few degrees C above ambient, so no heatsinking is required. Power budgeting should focus on sleep-mode current, not thermal limits.
Compliance Information
RoHS/lead-free status inferred from Microchip green packaging policy for current AVR parts; REACH, halogen-free, and conflict-minerals declarations were not present in the verified data - confirm on the Microchip product page certificate.
