ATMEGA32L-8AC - 8MHz 8-bit AVR MCU, 32KB Flash, 44-TQFP | Microchip
MPN: ATMEGA32L-8AC ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.92 | $8.92 |
| 10 | $8.03 | $80.30 |
| 100 | $7.15 | $715.00 |
| 500 | $6.45 | $3,225.00 |
| 1,000 | $5.85 | $5,850.00 |
ATMEGA32L-8AC Overview
What is an AVR microcontroller? An AVR microcontroller is a family of 8-bit RISC microcontrollers originally developed by Atmel (now part of Microchip Technology) and widely used in embedded systems. Microcontrollers sit at the bottom of the computing hierarchy, below microprocessors, and integrate a CPU core, non-volatile program memory, RAM, and peripherals onto a single die - making them ideal for deterministic real-time control. Within the ATmega family, the ATmega32L is the low-voltage (2.7V-5.5V) variant of the classic ATmega32, with the "L" denoting a relaxed 0-8 MHz speed grade at lower Vcc.
Key features include hardware multiplier support, six sleep modes for power management, an internal calibrated RC oscillator, watchdog timer with on-chip oscillator, and an external interrupt on every I/O pin. The 10-bit ADC supports up to 8 single-ended channels at the TQFP package's pinout, with optional internal bandgap reference and free-running or single-conversion modes. The 16-bit Timer/Counter1 with Input Capture and dual compare outputs makes it a strong fit for motor control, power conversion, and waveform generation.
Architecturally, the ATmega32L uses a Harvard-style memory layout with separate buses for program Flash and data SRAM, eliminating the von Neumann bottleneck. The 32 general-purpose working registers are directly connected to the ALU, enabling single-cycle arithmetic. The instruction pipeline overlaps fetch and execute, so most instructions complete in one clock cycle - a defining AVR performance advantage over 8051-class MCUs that require 12 cycles per instruction.
Typical applications include industrial control and sensor nodes, HVAC thermostat and building automation controllers, automotive body electronics and instrument clusters, consumer appliances (washing machines, microwave ovens), USB-to-serial bridges, hobbyist Arduino-class designs, low-power battery data loggers, and small motor control boards. The wide 2.7V-5.5V supply range and rich peripherals make it suitable for both line-powered and battery-backed products.
When designing with this part, the most important trade-off is the "L" speed grade: 8 MHz maximum clock at full Vcc range, compared to the 16 MHz-capable ATmega32-16AC. Designers must also provide proper decoupling (100 nF plus bulk 10 uF near Vcc/AVcc pins) and a stable ISP or JTAG programming path. The 44-TQFP footprint is footprint-compatible with the ATmega32-16AC and ATmega324A-AU variants, simplifying family migration.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone ATmega32L datasheet, helping engineers select and source the right part for their embedded design.
Drop-in alternatives for ATMEGA32L-8AC — 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-8AC (same form factor and footprint) — differing in Timers/Counters, ADC, Package, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
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✓ In Stock
$2.96 / Unit
View Datasheet →ATMEGA324PA-AU
✅ Drop-In✓ In Stock
$2.87 / Unit
View Datasheet →ATMEGA32L-8AC Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Program Memory (Flash) | 32 KB (16K x 16) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum Clock Frequency | 8 MHz |
| MIPS Throughput | 8 MIPS at 8 MHz |
| Supply Voltage (Vcc) | 2.7 V to 5.5 V |
| General-Purpose I/O Pins | 32 |
| ADC | 10-bit, 8 channels |
| Timer/Counters | 3 (two 8-bit, one 16-bit) |
| Communication Interfaces | USART, SPI, TWI (I2C) |
| Package | 44-pin TQFP (10x10 mm) |
| Operating Temperature | 0C to +70C (commercial grade) |
| On-chip Debug | JTAG (IEEE 1149.1 compliant) |
| Instruction Set | 131 instructions, mostly single-cycle |
| Mounting Type | Surface Mount |
ATMEGA32L-8AC Pin Configuration
| Pin 1 | PB5 (MOSI) — Port B bit 5 / SPI MOSI (also JTAG TDI) |
| Pin 2 | PB6 (MISO) — Port B bit 6 / SPI MISO (also JTAG TDO) |
| Pin 3 | PB7 (SCK) — Port B bit 7 / SPI SCK (also JTAG TMS) |
| Pin 4 | RESET — Reset input, active low |
| Pin 5 | VCC — Digital supply voltage |
| Pin 6 | GND — Digital ground |
| Pin 7 | XTAL2 — Crystal oscillator output |
| Pin 8 | XTAL1 — Crystal oscillator input |
| Pin 9 | PD0 (RXD) — Port D bit 0 / USART0 RXD |
| Pin 10 | PD1 (TXD) — Port D bit 1 / USART0 TXD |
| Pin 11 | PD2 (INT0) — Port D bit 2 / External Interrupt 0 |
| Pin 12 | PD3 (INT1) — Port D bit 3 / External Interrupt 1 |
| Pin 13 | PD4 (OC1B) — Port D bit 4 / Timer1 Compare B |
| Pin 14 | PD5 (OC1A) — Port D bit 5 / Timer1 Compare A |
| Pin 15 | PD6 (ICP1) — Port D bit 6 / Timer1 Input Capture |
| Pin 16 | PD7 (OC2) — Port D bit 7 / Timer2 Compare |
| Pin 17 | VCC — Digital supply voltage |
| Pin 18 | GND — Digital ground |
| Pin 19 | PC0 (SCL) — Port C bit 0 / TWI SCL |
| Pin 20 | PC1 (SDA) — Port C bit 1 / TWI SDA |
| Pin 21 | PC2 (TCK) — Port C bit 2 / JTAG TCK |
| Pin 22 | PC3 (TMS) — Port C bit 3 / JTAG TMS |
| Pin 23 | PC4 (TDI) — Port C bit 4 / JTAG TDI |
| Pin 24 | PC5 (TDO) — Port C bit 5 / JTAG TDO |
| Pin 25 | PC6 (TOSC1) — Port C bit 6 / Timer Oscillator pin 1 |
| Pin 26 | PC7 (TOSC2) — Port C bit 7 / Timer Oscillator pin 2 |
| Pin 27 | AVCC — Analog supply for PORTA ADC |
| Pin 28 | AREF — ADC reference voltage |
| Pin 29 | AGND — Analog ground |
| Pin 30 | PA7 (ADC7) — Port A bit 7 / ADC input channel 7 |
| Pin 31 | PA6 (ADC6) — Port A bit 6 / ADC input channel 6 |
| Pin 32 | PA5 (ADC5) — Port A bit 5 / ADC input channel 5 |
| Pin 33 | PA4 (ADC4) — Port A bit 4 / ADC input channel 4 |
| Pin 34 | PA3 (ADC3) — Port A bit 3 / ADC input channel 3 |
| Pin 35 | PA2 (ADC2) — Port A bit 2 / ADC input channel 2 |
| Pin 36 | PA1 (ADC1) — Port A bit 1 / ADC input channel 1 |
| Pin 37 | PA0 (ADC0) — Port A bit 0 / ADC input channel 0 |
| Pin 38 | VCC — Digital supply voltage |
| Pin 39 | GND — Digital ground |
| Pin 40 | PB0 (XCK0) — Port B bit 0 / USART0 external clock |
| Pin 41 | PB1 (T1) — Port B bit 1 / Timer1 external clock |
| Pin 42 | PB2 (AIN0) — Port B bit 2 / Analog Comparator positive input |
| Pin 43 | PB3 (AIN1) — Port B bit 3 / Analog Comparator negative input |
| Pin 44 | PB4 (SS) — Port B bit 4 / SPI Slave Select |
Typical Applications
ATMEGA32L-8AC is suitable for 6 applications: Industrial Sensor Node and Data Logger, HVAC Thermostat and Building Automation Controller, Consumer Appliance Control Board (Washing Machine, Microwave, Oven), USB-to-Serial Bridge and HID Device, Hobbyist and Educational Development Board, Small BLDC / Brushed DC Motor Control Board.
Industrial Sensor Node and Data Logger
The ATMEGA32L-8AC's 32KB Flash, 2KB SRAM, 1KB EEPROM, and 8-channel 10-bit ADC make it a strong fit for industrial sensor nodes that aggregate analog inputs, store calibration in EEPROM, and log samples locally. The wide 2.7V-5.5V supply range accepts both 3.3V and 5V transducers, and the six sleep modes let battery-powered nodes idle below 1 mA between measurements. Placed as the central MCU, it reads the sensors on PORTA, writes metadata to EEPROM, and wakes the radio on timer overflow. Trade-off: 8 MHz limits fast-signal DSP; if you need 100 kSPS continuous sampling, consider an external ADC or step up to ATmega32A.
Recommended
HVAC Thermostat and Building Automation Controller
Building automation controllers require reliable, deterministic real-time response and a wide operating voltage to share 24VAC-derived rails - both strengths of the ATMEGA32L-8AC. The 16-bit Timer/Counter1 with Input Capture supports zero-crossing detection for triac-based fan and damper control, while the ADC handles NTC thermistor temperature sensing on PORTA. The on-chip EEPROM stores scheduling tables and setpoint backups. Compared to a switching regulator + digital isolator approach, the ATmega32L's single-chip integration simplifies UL compliance. Limitation: only one USART means a slow IrDA or RS-485 uplink must share pins with the TWI bus to a keypad/RTC.
Recommended
Consumer Appliance Control Board (Washing Machine, Microwave, Oven)
The ATMEGA32L-8AC delivers 8 MIPS at 8 MHz, which is sufficient to drive a character LCD, scan a 4x4 keypad, control a buzzer, and run a 50/60 Hz mains-time base for safety interlocks - all on a single chip. The three Timer/Counters provide one for the user-interface tick, one for the motor PWM via Timer0 fast PWM, and one 16-bit Timer1 for the door-lock timeout. The 32 GPIO easily absorb the seven-segment and relay driver lines. Versus an 8051-class MCU, the AVR single-cycle core simplifies deterministic control loops; versus a Cortex-M0, the BOM cost is lower for non-graphics appliances.
Recommended
USB-to-Serial Bridge and HID Device
With hardware USART and a software-only USB low-speed implementation (or external V-USB firmware), the ATMEGA32L-8AC can serve as a USB-to-UART bridge, HID keyboard/mouse, or CDC-class adapter. The 32KB Flash is comfortable for the USB stack plus a small command interpreter, and 2KB SRAM is adequate for short bulk transfers. The 8 MHz internal RC oscillator can be tuned over USB to meet the 1.5% baud-rate accuracy requirement for full-speed CDC. A common pattern pairs this MCU with a USB-B connector and on-board 3.3V LDO; the wide Vcc range is helpful because USB VBUS can sag during plug-in events.
Recommended
Hobbyist and Educational Development Board
The ATMEGA32L-8AC's 32KB Flash, JTAG debug, breadboard-friendly 44-TQFP breakout, and Atmel Studio / avr-gcc toolchain make it a popular teaching platform for embedded systems courses. Students can program it via ISP or JTAG, examine registers in real time, and reuse the same code on Arduino-style boards (with minor pin remapping). Compared to the ATmega328P, the ATmega32L exposes more I/O and JTAG, which is ideal for assembly-language labs. Limitation: the 8 MHz grade means CPU-bound labs (FFT, CRC tables) run slower than on the 16 MHz ATmega32-16AC.
Recommended
Small BLDC / Brushed DC Motor Control Board
Using the 16-bit Timer/Counter1 in PWM mode with complementary outputs and the ADC to sense back-EMF or current shunt, the ATMEGA32L-8AC can drive small three-phase brushless DC or brushed DC motors up to a few hundred watts. The 8 MHz clock is sufficient for 20 kHz PWM with 8-bit duty resolution, and the 10-bit ADC samples current at the PWM midpoint with 1 us aperture. The on-chip comparator and interrupt-on-pin-change accelerate zero-crossing detection. Trade-off: there is no CAN on the ATmega32L, so for CAN-based motor networks you need the ATmega32C1 or ATmega32M1 family instead.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA32L-8AC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA32L-8AU | ATMEGA32A-AU | ATMEGA324PA-AU | ATMEGA32A-AUR |
|---|---|---|---|---|---|
| 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 |
| Brand | Microchip Technology (Atmel legacy) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 8 MHz | 8 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage (Vcc) | 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 | 2.7 V to 5.5 V |
| Program Memory (Flash) | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 2 KB |
| EEPROM | 1 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| GPIO Pins | 32 | 32 | 32 | 32 | 32 |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels |
| USART | 1 | 1 | 1 | 2 (with SPI expansion) | 1 |
Key Differentiators
- Wide 2.7V-5.5V supply range with 8 MHz speed grade (vs ATMEGA32A-AU)
- Two USARTs and richer peripheral set at the same footprint (vs ATMEGA324PA-AU)
- Through-hole variant available for breadboard and hobby use (vs ATMEGA32L-8PC)
Design Notes
Estimated: at 8 MHz and 5 V Vcc, active current is approximately 15-20 mA, dropping to 1-2 mA in Power-Save mode and below 1 uA in Power-Down. Place 100 nF decoupling ceramic capacitors directly at every Vcc/GND pair and add a 10 uF bulk near the AVcc pin to keep ADC measurements clean. If battery life matters more than wake-up latency, prefer Power-Save (Timer2 async) over Idle, since Idle still clocks the CPU core.
Keep the crystal traces short and symmetric to minimize parasitic capacitance; place a ground guard ring around the XTAL1/XTAL2 traces if the board has a switching converter nearby. For USB or CAN applications, the V-USB or external transceiver should be placed on the opposite side of the MCU with a clear ground return path. Do not route ADC traces under the crystal or digital switching nodes - this couples digital noise into analog measurements.
A frequent mistake is forgetting to disable JTAG via the MCUCSR/JTD fuse before using PORTC pins 2-5 as GPIO - otherwise the JTAG state machine drives those pins. Also, on first power-up, the device runs from the internal 1 MHz RC oscillator by default; if your firmware assumes an 8 MHz external crystal, the timing will be off by 8x. Set the CKSEL fuses correctly and confirm with an LED blink or UART output before soldering the final firmware. Brown-Out Detection (BOD) should be enabled in any line-powered design to prevent Flash corruption at low Vcc.
Compliance Information
RoHS and REACH compliant per Microchip product page. Commercial 0C to +70C temperature grade. Not AEC-Q100 qualified; for automotive use, select ATmega32-16AU automotive-grade variant.