ATMEGA32L-8AI - 8-bit AVR MCU 32KB Flash 8MHz | Microchip
MPN: ATMEGA32L-8AI ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.42 | $74.20 |
| 100 | $6.85 | $685.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.62 | $5,620.00 |
ATMEGA32L-8AI Overview
An 8-bit microcontroller is a small computer-on-a-chip containing a CPU, memory (Flash for program code, SRAM for runtime data, EEPROM for non-volatile storage), and a rich set of programmable peripherals such as timers, ADC, USART, SPI, and I2C. Within the broader semiconductor taxonomy, an MCU sits under microcontrollers -> embedded processors -> integrated circuits. The AVR family, originally developed by Atmel and now under Microchip, is a RISC (Reduced Instruction Set Computer) architecture known for single-cycle execution of most instructions, making it well-suited to deterministic embedded control. Low-power variants (the 'L' suffix in the part number) support operation down to 2.7V.
Key features of the ATMEGA32L-8AI include 32 programmable I/O lines, an 8-channel 10-bit ADC, two 8-bit timers plus one 16-bit timer, a watchdog timer, an on-chip analog comparator, and full JTAG debug support via the four-wire interface. The device integrates the AVR core with hardware multiplier and 32 working registers, providing up to 8 MIPS throughput at 8MHz.
The architecture uses a Harvard-style bus with separate program and data memories, allowing instruction fetch and data access in a single clock cycle. The on-chip bootloader (via UART) enables in-system programming without external programmers, while JTAG and debugWIRE interfaces support real-time in-circuit emulation. The 10-bit successive-approximation ADC delivers up to 15 ksps with optional noise reduction mode.
Typical applications include industrial control systems, sensor hubs, HVAC controllers, motor control boards, battery-powered instruments, and embedded data loggers. The wide operating voltage range (2.7V to 5.5V) and low-power modes (Power-Save, Power-Down drawing microampere-level currents) make it attractive for energy-conscious designs.
When designing with this part, mind the VCC decoupling (100 nF plus 10 uF bulk), keep the reset pin decoupled to avoid spurious resets, and select the correct fuse configuration for the clock source. The TQFP-44 footprint is industry-standard and broadly drop-in compatible with later ATmega32A and ATmega32U4 derivatives in the same package.
This page synthesizes distributor pricing, drop-in TQFP-44 alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA32L-8AI — 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 ATMEGA32L-8AI (same form factor and footprint) — differing in Package, Timers/Counters, ADC, Core Architecture, Debug Interface.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA32L-8AC
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.85 / Unit
View Datasheet →ATMEGA32L-8AU
✅ Drop-In✓ In Stock
$3.72 / Unit
View Datasheet →ATMEGA32A-AU
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →ATMEGA32A-AUR
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.96 / Unit
View Datasheet →ATMEGA32A-AN
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.4 / Unit
View Datasheet →ATMEGA329V-8AI
✅ Drop-In✓ In Stock
$4.45 / Unit
View Datasheet →ATMEGA32L-8AI Maximum Ratings & Electrical Characteristics
| Architecture | AVR 8-bit RISC |
| Core | AVR |
| Program Memory | 32 KB Flash (in-system programmable) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum CPU Speed | 8 MHz |
| Operating Voltage | 2.7 V to 5.5 V |
| I/O Pins | 32 programmable I/O lines |
| ADC | 8-channel, 10-bit |
| Timers | Two 8-bit + One 16-bit |
| Communication | USART, SPI, I2C (TWI) |
| Watchdog Timer | Yes |
| On-chip Analog Comparator | Yes |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| Debug Interface | JTAG / debugWIRE |
| Throughput | 8 MIPS at 8 MHz |
| RoHS Status | Compliant |
ATMEGA32L-8AI Pin Configuration
| Pin 1 | PB0 (XCK0/T0) — Port B bit 0 / USART0 clock / Timer0 input |
| Pin 2 | PB1 (T1) — Port B bit 1 / Timer1 input |
| Pin 3 | PB2 (AIN0/SS) — Port B bit 2 / Analog comparator input / SPI SS |
| Pin 4 | PB3 (AIN1/MOSI) — Port B bit 3 / Analog comparator input / SPI MOSI |
| Pin 5 | PB4 (SS/MISO) — Port B bit 4 / SPI SS or MISO (alt function) |
| Pin 6 | PB5 (MOSI) — Port B bit 5 / SPI MOSI |
| Pin 7 | PB6 (MISO) — Port B bit 6 / SPI MISO |
| Pin 8 | PB7 (SCK) — Port B bit 7 / SPI clock |
| Pin 9 | RESET — Reset input (active low) |
| Pin 10 | VCC — Digital supply voltage |
| Pin 11 | GND — Digital ground |
| Pin 12 | XTAL2 — Crystal oscillator output |
| Pin 13 | XTAL1 — Crystal oscillator input |
| Pin 14 | PD0 (RXD) — Port D bit 0 / USART0 RXD |
| Pin 15 | PD1 (TXD) — Port D bit 1 / USART0 TXD |
| Pin 16 | PD2 (INT0) — Port D bit 2 / External interrupt 0 |
| Pin 17 | PD3 (INT1) — Port D bit 3 / External interrupt 1 |
| Pin 18 | PD4 (OC1B) — Port D bit 4 / Timer1 output compare B |
| Pin 19 | PD5 (OC1A) — Port D bit 5 / Timer1 output compare A |
| Pin 20 | PD6 (ICP1) — Port D bit 6 / Timer1 input capture |
| Pin 21 | PD7 (OC2) — Port D bit 7 / Timer2 output compare |
| Pin 22 | PC0 (SCL) — Port C bit 0 / I2C SCL |
| Pin 23 | PC1 (SDA) — Port C bit 1 / I2C SDA |
| Pin 24 | PC2 (TCK) — Port C bit 2 / JTAG TCK |
| Pin 25 | PC3 (TMS) — Port C bit 3 / JTAG TMS |
| Pin 26 | PC4 (TDO) — Port C bit 4 / JTAG TDO |
| Pin 27 | PC5 (TDI) — Port C bit 5 / JTAG TDI |
| Pin 28 | PC6 (TOSC1) — Port C bit 6 / Timer oscillator pin 1 |
| Pin 29 | PC7 (TOSC2) — Port C bit 7 / Timer oscillator pin 2 |
| Pin 30 | VCC — Digital supply voltage (second VCC pin) |
| Pin 31 | AVSS — Analog ground |
| Pin 32 | GND — Digital ground (second GND pin) |
| Pin 33 | AREF — ADC analog reference voltage |
| Pin 34 | PA7 (ADC7) — Port A bit 7 / ADC channel 7 |
| Pin 35 | PA6 (ADC6) — Port A bit 6 / ADC channel 6 |
| Pin 36 | PA5 (ADC5) — Port A bit 5 / ADC channel 5 |
| Pin 37 | PA4 (ADC4) — Port A bit 4 / ADC channel 4 |
| Pin 38 | PA3 (ADC3) — Port A bit 3 / ADC channel 3 |
| Pin 39 | PA2 (ADC2) — Port A bit 2 / ADC channel 2 |
| Pin 40 | PA1 (ADC1) — Port A bit 1 / ADC channel 1 |
| Pin 41 | PA0 (ADC0) — Port A bit 0 / ADC channel 0 |
| Pin 42 | AVCC — Analog supply voltage |
| Pin 43 | GND — Digital ground (third GND pin) |
| Pin 44 | VCC — Digital supply voltage (third VCC pin) |
Typical Applications
ATMEGA32L-8AI is suitable for 6 applications: Industrial Sensor Hub, Battery-Powered Data Logger, HVAC Climate Controller, Motor Control Board, Embedded User Interface Panel, Educational / Maker Development Board.
Industrial Sensor Hub
The ATMEGA32L-8AI fits industrial sensor hubs thanks to its 8-channel 10-bit ADC, 32 programmable I/O lines, and 2.7V to 5.5V supply range. At 8 MHz it samples multiple analog sensors (temperature, pressure, flow) and routes data through USART to a host PLC. Its industrial -40C to +85C temperature rating and JTAG debug interface make it well suited to factory-floor deployments where deterministic interrupt response and field serviceability matter. The 32 KB Flash holds a typical Modbus-RTU firmware plus calibration tables with headroom.
Recommended
Battery-Powered Data Logger
The 'L' suffix of the ATMEGA32L-8AI signals low-power operation; combined with Power-Save and Power-Down modes that draw microampere-level currents, this part suits battery-powered data loggers that wake on timer or interrupt to record sensor samples. Its 1 KB EEPROM stores calibration data and non-volatile log markers without external FRAM. With 8 MHz active CPU speed the device wakes, captures, and returns to sleep fast enough to keep average current in the sub-100 uA range across typical 10-second logging intervals, extending coin-cell or Li-SOCl2 battery life to years.
Recommended
HVAC Climate Controller
The ATMEGA32L-8AI's 32 I/O lines directly drive HVAC actuator triacs, fan PWM outputs, and a character LCD via parallel interface, while its three timers handle closed-loop fan speed control and defrost scheduling. The 10-bit ADC reads thermistor bridges for supply/return air, and the I2C (TWI) bus interfaces to an external RTC and EEPROM for schedule storage. Industrial temperature grade ensures reliable operation in unconditioned plant rooms. The 32 KB Flash holds complex scheduling logic and a USB bootloader for firmware updates.
Recommended
Motor Control Board
For brushed DC and stepper motor control, the ATMEGA32L-8AI's 16-bit Timer/Counter1 generates precise PWM with hardware dead-time insertion, while its fast 8-bit timers handle quadrature encoder inputs. The 32 I/O lines interface to H-bridge drivers, current-sense amplifiers, and limit switches. At 8 MHz CPU speed, the control loop fits in well under 100 us, providing smooth torque regulation. The industrial temp grade ensures reliable operation near motor windings where ambient temperatures routinely exceed 60C in enclosed cabinets.
Recommended
Embedded User Interface Panel
The ATMEGA32L-8AI drives character and small graphic LCDs, scan-matrix keypads, and rotary encoders from its 32 I/O lines, while USART talks to a host controller for back-office data. The 32 KB Flash supports a button-debounce FSM, multi-screen menu logic, and I2C peripherals (EEPROM for settings, RTC for timestamps) without external memory. JTAG debug accelerates bring-up of the keypad scanning algorithm. The TQFP-44 footprint suits compact hand-held enclosures common in industrial operator panels.
Recommended
Educational / Maker Development Board
The ATMEGA32L-8AI appears in low-cost AVR development boards and teaching kits thanks to its through-hole-friendly TQFP-44 breakout availability, native JTAG/debugWIRE for step-through debugging, and free AVR Studio toolchain support. Students learn ADC sampling, timer interrupts, and USART communication on a real industrial-grade MCU. The on-chip bootloader simplifies firmware upload over a USB-to-serial cable without an external programmer, making classroom deployment straightforward. 32 KB Flash accommodates substantial student projects with multiple peripherals active.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA32L-8AI — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA32L-8AC | ATMEGA32L-8AU | ATMEGA32A-AU | ATMEGA32A-AUR | ATMEGA32A-AN | ATMEGA329V-8AI |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 | TQFP-44 (same) | TQFP-44 (same) | TQFP-44 (same) | TQFP-44 (same) | TQFP-44 (same) | TQFP-44 (same) |
| Core / Architecture | AVR 8-bit | AVR 8-bit | AVR 8-bit | AVR 8-bit | AVR 8-bit | AVR 8-bit | AVR 8-bit |
| Program Memory | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB Flash |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Maximum Frequency | 8 MHz | 8 MHz | 8 MHz | 16 MHz (configurable to 8 MHz) | 16 MHz (configurable to 8 MHz) | 16 MHz (configurable to 8 MHz) | 8 MHz |
| Operating Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V |
| Temperature Grade | Industrial -40C to +85C | Commercial 0C to +70C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C |
| RoHS / Lead-Free | RoHS compliant | RoHS compliant | Pb-free / lead-free | Pb-free / lead-free | Pb-free / lead-free | Pb-compliant variant | RoHS compliant |
Key Differentiators
- Original ATmega32 silicon with industrial temperature grade (vs ATMEGA32L-8AC)
- Modern ATmega32A revision with lower active current (vs ATMEGA32A-AU)
- Same TQFP-44 package vs. ATmega328P-PU 45Hz-class compact MCU (vs ATmega328P-PU)
- TQFP-44 surface-mount vs. PDIP-40 through-hole ATmega32A-PU (vs ATmega32A-PU)
Design Notes
Estimated: At VCC = 5V, 8 MHz active CPU speed, the ATMEGA32L-8AI draws approximately 10-15 mA active. Place a 100 nF decoupling capacitor close to each VCC pin (10, 30, 44) and a single 10 uF bulk capacitor on the supply rail. AVCC (pin 42) must be tied to VCC with its own 100 nF + 10 uF LC filter to keep ADC noise low; otherwise ADC readings will show 5-10 LSB jitter.
Keep the crystal traces (XTAL1/XTAL2, pins 12/13) short and surrounded by a ground pour on both sides of the PCB to minimize EMI. For noise-sensitive designs, use a 4-layer PCB with the inner layer dedicated to ground; for hobby projects a 2-layer PCB works if the crystal area is kept clear. The RESET pin (pin 9) should have a 10 kohm pull-up to VCC and a 100 nF capacitor to ground for proper brown-out behavior.
The ATMEGA32L-8AI ships from the factory with the internal 1 MHz RC oscillator enabled and CKDIV8 fuse set, meaning most new parts run at 1 MHz by default. If your firmware assumes 8 MHz, the timing routines will be off by 8x. Either program the correct fuse settings before first use or include AVR LibC's F_CPU definition in your toolchain to match the actual operating frequency. Also, the JTAGEN fuse is enabled by default - disable it if you need PC2-PC5 as GPIO.
Estimated: At maximum VCC (5.5V) and 8 MHz active, power dissipation is roughly 50 mW worst-case (VCC x I_active = 5.5V x 9 mA). The TQFP-44 package has theta_JA around 50 C/W, so junction temperature rise above ambient is only ~2.5 C - thermal management is not a concern for this part. However, if your design forces the part into a sealed enclosure with no airflow, ensure ambient stays below 70 C to provide adequate margin to the 85 C industrial limit.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified; for automotive use select a -Q1 suffix variant. Halogen-free and lead-free per Microchip material content disclosures.