ATMEGA32-16AC - 8-bit AVR MCU 16MHz 32KB Flash | Microchip
MPN: ATMEGA32-16AC β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.9 | $6.90 |
| 10 | $6.21 | $62.10 |
| 100 | $5.52 | $552.00 |
| 500 | $4.97 | $2,485.00 |
| 1,000 | $4.48 | $4,480.00 |
ATMEGA32-16AC Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, program memory, data memory, and peripherals such as timers, UARTs, and ADCs into one chip. The ATmega32 belongs to the AVR family of enhanced RISC microcontrollers, positioned within the broader embedded processor hierarchy beneath 32-bit ARM MCUs, and is a classic member of the 8-bit microcontroller class used throughout industrial and consumer electronics.
Key features include 131 powerful instructions with mostly single-cycle execution, 32 general-purpose working registers, an 8-channel 10-bit ADC, a JTAG interface for on-chip debugging and boundary scan, and self-programming Flash enabling boot-loader based field updates. These peripherals allow a single ATmega32 to replace multi-chip analog-and-logic designs.
Architecturally, the AVR core uses a Harvard structure with separate program and data buses, so instruction fetch and data access occur in parallel. With most instructions executing in a single clock cycle, the device achieves close to 1 MIPS per MHz, letting designers run at lower clock frequencies for reduced power while maintaining throughput. Operating voltage is 4.5 V to 5.5 V, making the -16AC grade well matched to 5 V industrial logic levels.
Typical applications include industrial control panels, HVAC and building automation, motor control front ends, and 5 V legacy instrumentation where the 10-bit ADC, two 8-bit timers, one 16-bit timer, USART, SPI, and TWI (I2C) interfaces cover the full sensing and communication need of a compact controller.
A key design consideration is that the -16AC grade specifies operation at 4.5 V to 5.5 V; designs needing 2.7 V to 5.5 V operation should select the ATmega32L variant. Decouple VCC and AVCC separately with 100 nF capacitors placed close to the pins.
This page synthesizes verified distributor data, drop-in alternatives, pinout information, and practical design notes in one place - information not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for ATMEGA32-16AC 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 ATMEGA32-16AC (same form factor and footprint) β differing in Package, Debug Interface, Timers, Core Architecture, EEPROM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA32A-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA32-16AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA16A-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$2.05 / Unit
View Datasheet βATMEGA8535-16AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA324PA-AU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA32-16AC Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 32 KB (16K x 16) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| Maximum Clock Frequency | 16 MHz |
| Throughput | 16 MIPS at 16 MHz |
| Operating Voltage Range | 4.5 V to 5.5 V |
| ADC Resolution | 10-bit |
| ADC Channels | 8 channels |
| Number of I/O Pins | 32 |
| Timers | Two 8-bit, one 16-bit |
| Communication Interfaces | USART, SPI, TWI (I2C) |
| Debug Interface | JTAG (on-chip debug, boundary scan) |
| Package | 44-TQFP (10 x 10 mm) |
| Mounting Type | Surface Mount |
| Instructions | 131 instructions, most single-cycle |
| Product Family | AVR ATmega |
ATMEGA32-16AC 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 | PB7 (OC2/OC1C) β Port B bit 7 / Timer2 output compare |
| Pin 12 | PB6 (OC1B) β Port B bit 6 / Timer1 output compare B |
| Pin 13 | PB5 (OC1A) β Port B bit 5 / Timer1 output compare A |
| Pin 14 | PB4 (OC0) β Port B bit 4 / Timer0 output compare |
| Pin 15 | PB3 (AIN1) β Port B bit 3 / Analog comparator negative input |
| Pin 16 | PB2 (AIN0/INT2) β Port B bit 2 / Comparator positive input / External interrupt 2 |
| Pin 17 | PB1 (T1) β Port B bit 1 / Timer1 external counter input |
| Pin 18 | PB0 (XCK/T0) β Port B bit 0 / USART external clock / Timer0 counter input |
| Pin 19 | PD7 (OC2) β Port D bit 7 / Timer2 output compare |
| Pin 20 | PD6 (ICP1) β Port D bit 6 / Timer1 input capture |
| Pin 21 | PD5 (OC1A) β Port D bit 5 / Timer1 output compare A |
| Pin 22 | PD4 (OC1B) β Port D bit 4 / Timer1 output compare B |
| Pin 23 | PD3 (INT1) β Port D bit 3 / External interrupt 1 |
| Pin 24 | PD2 (INT0) β Port D bit 2 / External interrupt 0 |
| Pin 25 | PD1 (TXD) β Port D bit 1 / USART transmit |
| Pin 26 | PD0 (RXD) β Port D bit 0 / USART receive |
| Pin 27 | PC7 (TCK) β Port C bit 7 / JTAG test clock |
| Pin 28 | PC6 (TMS) β Port C bit 6 / JTAG test mode select |
| Pin 29 | PC5 (TDO) β Port C bit 5 / JTAG test data output |
| Pin 30 | PC4 (TDI) β Port C bit 4 / JTAG test data input |
| Pin 31 | PC3 (TOSC2) β Port C bit 3 / Timer oscillator output |
| Pin 32 | PC2 (TOSC1) β Port C bit 2 / Timer oscillator input |
| Pin 33 | PC1 (SDA) β Port C bit 1 / TWI data |
| Pin 34 | PC0 (SCL) β Port C bit 0 / TWI clock |
| Pin 35 | VCC β Digital supply voltage |
| Pin 36 | GND β Ground |
| Pin 37 | AREF β ADC reference voltage |
| Pin 38 | AVCC β ADC supply voltage |
| Pin 39 | RESET β Reset input (active low) |
| Pin 40 | XTAL1 β Crystal/oscillator input |
| Pin 41 | XTAL2 β Crystal/oscillator output |
| Pin 42 | GND β Ground |
| Pin 43 | AVCC β ADC supply voltage |
| Pin 44 | AREF β ADC reference voltage |
Typical Applications
ATMEGA32-16AC is suitable for 6 applications: Industrial Control Panels, Analog Data Acquisition, HVAC and Building Automation, Motor Control Front Ends, 5V Legacy Instrumentation Maintenance, Educational and Embedded Prototyping.
Industrial Control Panels
The ATMEGA32-16AC fits industrial control panels because its 4.5 V to 5.5 V operating range matches legacy 5 V PLC-style logic directly, and its 32 KB flash is large enough for PID loops, state machines, and HMI communication firmware. Per the datasheet, the JTAG interface supports on-chip debugging, which shortens commissioning of panel logic. Typical usage places the MCU at the center of a relay/timer/counter board, using the USART (RXD/TXD pins) for Modbus-style serial links and the 16-bit Timer/Counter1 for precise timing. Because instructions mostly execute in one cycle, deterministic I/O response is achieved without RTOS overhead; the trade-off is that 5 V operation raises power versus 3.3 V MCUs, so board dissipation should be budgeted.
Recommended
Analog Data Acquisition
With an 8-channel 10-bit ADC multiplexed onto Port A (pins 1-8), the ATMEGA32-16AC serves as a complete low-cost data acquisition front end for temperature, pressure, and voltage sensing. Per the datasheet, the ADC supports a reference from AREF (pin 37) or AVCC (pin 38), enabling 4.88 mV resolution on a 5 V reference; the 1 KB EEPROM stores calibration constants across power cycles. Designers typically sample channels sequentially with the built-in prescaler and stream results over USART or SPI. Performance consideration: ADC accuracy degrades if digital port switching injects noise into AVCC, so a separate LC filter on AVCC is recommended. The 2 KB SRAM comfortably buffers sample blocks for averaging before transmission.
Recommended
HVAC and Building Automation
Building automation nodes benefit from the ATMEGA32-16AC combination of 32 programmable I/O lines, TWI (I2C) on Port C for sensor expansion, and 5 V noise immunity suited to electrically harsh plant rooms. The TWI interface (SDA/SCL on PC1/PC0) connects RTCs, EEPROMs, and humidity sensors, while Timer/Counter PWM outputs (OC0, OC1A, OC1B, OC2) drive damper actuators and fan speed control. Firmware for scheduling and communication fits within 32 KB flash with room for boot-loader updates via the self-programming flash feature. Per the datasheet, the JTAG boundary-scan capability aids production test of assembled boards. For outdoor or unheated enclosures, choose the industrial-grade ATMEGA32-16AU which shares the identical footprint.
Recommended
Motor Control Front Ends
The ATMEGA32-16AC provides the timing resources needed for small motor control: one 16-bit timer (Timer1) with two compare outputs (OC1A on PD5, OC1B on PD4) plus two 8-bit timers, enabling multi-channel PWM generation for DC and stepper motor drivers. The input capture pin (ICP1, PD6) permits precise measurement of tachometer or encoder periods, closing speed loops in software. Its 16 MIPS at 16 MHz throughput, per the datasheet, leaves adequate headroom for PI control at several-kilohertz loop rates. Design consideration: the MCU cannot drive motors directly - pair it with an H-bridge driver such as the L298 or MOSFET pre-drivers, and use the 10-bit ADC channel on PA0-PA7 for current-sense feedback through a shunt amplifier.
Recommended
5V Legacy Instrumentation Maintenance
Service and maintenance of existing 5 V instruments is a primary remaining use case for the original ATmega32 die. The ATMEGA32-16AC keeps old designs serviceable with the exact original component, avoiding any requalification that a die-shrunk substitute might trigger. Its JTAG interface (TCK/TMS/TDO/TDI on PC7-PC4) allows re-flashing and on-chip-debug of boards already installed in the field when the self-programming boot loader is present. Per the datasheet, boundary-scan through the same JTAG port verifies board interconnects after repair. When stocks of the -16AC run out, the ATMEGA32A-AU is the verified drop-in successor, matching the 44-TQFP footprint and all electrical specifications of the original.
Recommended
Educational and Embedded Prototyping
The ATmega32 remains a staple of embedded-systems education because it exposes every classic MCU subsystem - GPIO, timers, ADC, UART, SPI, I2C, and external interrupts (INT0/INT1/INT2 on PD2, PD3, PB2) - in a single 44-TQFP device with free toolchains and abundant course material. The 32 KB flash provides generous space for student projects, and in-system programming through the SPI pins (MISO/MOSI/SCK on PB6/PB5/PB7) needs only a low-cost ISP programmer. Per the datasheet, the JTAG OCD interface also supports step debugging in AVR Studio-based flows. Its 5 V operation simplifies breadboard use with 5 V peripherals; students should still decouple AVCC separately for clean ADC experiments.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA32-16AC β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA32A-AU | ATMEGA32-16AU | ATMEGA16A-AU | ATMEGA8535-16AU |
|---|---|---|---|---|---|
| Package | 44-TQFP (10 x 10 mm) | 44-TQFP (10 x 10 mm) - same | 44-TQFP (10 x 10 mm) - same | 44-TQFP (10 x 10 mm) - same | 44-TQFP (10 x 10 mm) - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 32 KB | 32 KB | 32 KB | 16 KB | 8 KB |
| SRAM | 2 KB | 2 KB | 2 KB | 1 KB | 512 B |
| EEPROM | 1 KB | 1 KB | 1 KB | 512 B | 512 B |
| Max Clock Frequency | 16 MHz | 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 (16 MHz grade) | 4.5 V to 5.5 V |
| Operating Temperature | Commercial grade (0C to +70C) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| 10-bit ADC Channels | 8 | 8 | 8 | 8 | 8 |
| JTAG Debug | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Full 32 KB flash with pin-compatible shrink path (vs ATMEGA16A-AU)
- Original-die availability for legacy requalification (vs ATMEGA32A-AU)
- Commercial-grade cost advantage (vs ATMEGA32-16AU)
- More memory than same-package ATmega8535 (vs ATMEGA8535-16AU)
Design Notes
Decouple both VCC pairs (pins 9 and 35) with 100 nF ceramic capacitors placed within 5 mm of each pin, plus one 4.7 uF bulk capacitor per board. AVCC (pins 38/43) must be connected to VCC even if the ADC is unused, per the datasheet, but route it through a 10 uH inductor or ferrite bead with a separate 100 nF decoupler to keep digital switching noise out of ADC reference path. Keep AREF (pins 37/44) decoupled with 100 nF to ground and never drive it directly from a low-impedance source without a series resistor.
JTAG is enabled by default on Port C (pins PC4-PC7), which means PC4-PC7 cannot be used as general-purpose I/O until the JTAGEN fuse is disabled. Many designs fail at bring-up because outputs on Port C appear stuck. If JTAG debugging is not needed, clear the JTAGEN fuse via ISP programming; alternatively the JTD bit in MCUCSR can disable JTAG in software after two write cycles within four cycles, per the datasheet. Also remember RESET (pin 39) needs a 10 kOhm pull-up for reliable ISP programming when external circuitry loads the pin.
The -16AC grade requires 4.5 V minimum for guaranteed 16 MHz operation; designs powered from a marginal 5 V rail (e.g., long cables or diode-dropped supplies) should measure worst-case rail voltage under full load. Estimated: at 16 MHz with typical toggling I/O, core current is roughly 15-25 mA per family datasheet curves, so total board draw including I/O loads determines regulator sizing. Brown-out detection (BOD fuse) at 4.0 V is recommended to prevent flash corruption during slow power-down - enable BODLEVEL appropriately for a 5 V system.
Route XTAL1/XTAL2 (pins 40/41) crystal traces short and symmetric, with the crystal ground shields returned directly to the nearest GND pin (10 or 42). Keep clock traces away from ADC input traces on Port A to minimize crosstalk into conversions. For USART runs longer than a few tens of centimeters, add RS-485/RS-232 transceivers rather than driving TTL levels off-board. Underside of the TQFP has no exposed pad on this package, so thermal relief is straightforward but copper pours under the part still aid noise reduction.
Compliance Information
The original ATmega32 (non-A) die predates later green/RoHS packaging rollouts; RoHS/REACH status for the -16AC suffix must be confirmed from the official Microchip product page or certificate of conformance. The newer ATMEGA32A-AU is the RoHS-oriented replacement.
