ATMEGA16-16PU - 8-bit AVR MCU, 16MHz, 16KB Flash | Microchip
MPN: ATMEGA16-16PU β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.42 | $6.42 |
| 10 | $5.78 | $57.80 |
| 100 | $4.95 | $495.00 |
| 500 | $4.35 | $2,175.00 |
| 1,000 | $3.88 | $3,880.00 |
ATMEGA16-16PU Overview
An 8-bit microcontroller (MCU) is a single integrated circuit that contains a processor core, memory, and programmable input/output peripherals on one chip, forming the lowest tier of the embedded systems hierarchy: MCU -> embedded processor -> microprocessor -> semiconductor device. AVR MCUs from Microchip use an advanced RISC Harvard architecture in which most instructions execute in a single clock cycle, delivering roughly 1 MIPS per MHz of clock frequency.
Key features of the ATMEGA16-16PU include 16KB (8K x 16) of self-programmable Flash memory, 512B EEPROM, 1KB internal SRAM, an 8-channel 10-bit ADC, and a JTAG interface for on-chip debugging and boundary-scan. The device achieves up to 16 MIPS throughput at 16MHz and operates from a 4.5V to 5.5V supply in this speed/voltage grade. Peripherals include two 8-bit timers, one 16-bit timer, four PWM channels, USI-capable SPI, TWI (I2C-compatible), and a full-duplex USART for serial communication.
Architecturally, the AVR core uses 32 general-purpose 8-bit working registers directly connected to the ALU, allowing two independent registers to be accessed in one instruction executed in one clock cycle. This register file plus single-cycle execution is what differentiates AVR from the older 8051 architecture, which requires multiple cycles per instruction. In-system programmable (ISP) Flash enables firmware updates through the SPI port without removing the chip from the socket, and lock bits provide code protection.
Typical applications include industrial control and automation nodes, motor control and relay-driving boards, sensor-interface and data-logger systems, and hobby/education platforms such as Arduino-compatible boards built with the MightyCore hardware package.
A key design consideration: the 16PU speed grade requires a 4.5V to 5.5V supply, so designs running at 3.3V must select the ATmega16L-8AU/8PU 8MHz grade or migrate to a newer ATmega324-family part.
This page synthesizes distributor pricing tiers, drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA16-16PU 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 ATMEGA16-16PU (same form factor and footprint) β differing in Operating Temperature, Core Architecture, Debug Interface, Instructions, Supply Voltage Range.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA16-16PI
β Drop-Inβ In Stock
$3.72 / Unit
View Datasheet βATMEGA16A-PU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA32A-PU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA8535-16PU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA164A-PU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$3.15 / Unit
View Datasheet βATMEGA162-16PU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$3.1 / Unit
View Datasheet βATMEGA16-16PU Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-Bit |
| Speed | 16 MHz |
| Program Memory Size | 16KB (8K x 16) Flash |
| EEPROM Size | 512B |
| RAM Size | 1KB SRAM |
| Supply Voltage | 4.5 V to 5.5 V |
| Number of I/O | 32 |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| ADC Resolution | 10-bit |
| Number of ADC Channels | 8 |
| Communication Interfaces | SPI, UART/USART, TWI (I2C) |
| Debug Interface | JTAG (on-chip debug and boundary scan) |
| Package | 40-PDIP |
| Mounting Type | Through Hole |
| Operating Temperature | 0C to +70C (commercial, C suffix) |
| RISC Performance | Up to 16 MIPS at 16 MHz |
| RoHS Status | Compliant |
ATMEGA16-16PU Pin Configuration
| Pin 1 | PB0 (XCK/T0) β Port B bit 0 / USART external clock / Timer0 external clock |
| Pin 2 | PB1 (T1) β Port B bit 1 / Timer1 external clock |
| Pin 3 | PB2 (AIN0/INT2) β Port B bit 2 / Analog comparator positive input / External interrupt 2 |
| Pin 4 | PB3 (AIN1/OC0) β Port B bit 3 / Comparator negative input / Timer0 PWM output |
| Pin 5 | PB4 (SS) β Port B bit 4 / SPI slave select |
| Pin 6 | PB5 (MOSI) β Port B bit 5 / SPI master output / ISP programming data in |
| Pin 7 | PB6 (MISO) β Port B bit 6 / SPI master input / ISP programming data out |
| Pin 8 | PB7 (SCK/UCSK) β Port B bit 7 / SPI serial clock / ISP programming clock |
| Pin 9 | RESET β Active-low reset input / ISP programming reset |
| Pin 10 | VCC β Digital supply voltage (4.5V to 5.5V for 16PU) |
| Pin 11 | GND β Digital ground |
| Pin 12 | XTAL2 β Crystal oscillator output 2 |
| Pin 13 | XTAL1 β Crystal oscillator input 1 / external clock input |
| Pin 14 | PD0 (RXD) β Port D bit 0 / USART receive data |
| Pin 15 | PD1 (TXD) β Port D bit 1 / USART transmit data |
| Pin 16 | PD2 (INT0) β Port D bit 2 / External interrupt 0 |
| Pin 17 | PD3 (INT1) β Port D bit 3 / External interrupt 1 |
| Pin 18 | PD4 (OC1B) β Port D bit 4 / Timer1 output compare B PWM output |
| Pin 19 | PD5 (OC1A) β Port D bit 5 / Timer1 output compare A PWM output |
| Pin 20 | PD6 (ICP1) β Port D bit 6 / Timer1 input capture |
| Pin 21 | PD7 (OC2) β Port D bit 7 / Timer2 output compare PWM output |
| Pin 22 | PC0 (SCL) β Port C bit 0 / TWI (I2C) serial clock |
| Pin 23 | PC1 (SDA) β Port C bit 1 / TWI (I2C) serial data |
| Pin 24 | PC2 (TCK) β Port C bit 2 / JTAG test clock |
| Pin 25 | PC3 (TMS) β Port C bit 3 / JTAG test mode select |
| Pin 26 | PC4 (TDO) β Port C bit 4 / JTAG test data output |
| Pin 27 | PC5 (TDI) β Port C bit 5 / JTAG test data input |
| Pin 28 | PC6 (TOSC1) β Port C bit 6 / Timer2 oscillator input (32.768 kHz RTC crystal) |
| Pin 29 | PC7 (TOSC2) β Port C bit 7 / Timer2 oscillator output |
| Pin 30 | AVCC β ADC supply voltage (connect to VCC through low-pass filter) |
| Pin 31 | GND (AGND) β Analog ground |
| Pin 32 | AREF β ADC analog reference voltage |
| Pin 33 | PA0 (ADC0) β Port A bit 0 / ADC channel 0 |
| Pin 34 | PA1 (ADC1) β Port A bit 1 / ADC channel 1 |
| Pin 35 | PA2 (ADC2) β Port A bit 2 / ADC channel 2 |
| Pin 36 | PA3 (ADC3) β Port A bit 3 / ADC channel 3 |
| Pin 37 | PA4 (ADC4) β Port A bit 4 / ADC channel 4 |
| Pin 38 | PA5 (ADC5) β Port A bit 5 / ADC channel 5 |
| Pin 39 | PA6 (ADC6) β Port A bit 6 / ADC channel 6 |
| Pin 40 | PA7 (ADC7) β Port A bit 7 / ADC channel 7 |
Typical Applications
ATMEGA16-16PU is suitable for 6 applications: Industrial Control and Automation Nodes, Motor Control and PWM Actuation, Sensor Interface and Data Logging, Education and Hobby Embedded Platforms, Serial Communication Gateways, Legacy PCB Maintenance and Repair.
Industrial Control and Automation Nodes
The ATMEGA16-16PU fits industrial control nodes because it combines 32 I/O lines with a 5V-tolerant through-hole PDIP package that survives harsh wiring environments and simplifies field replacement. Its 16 MIPS throughput at 16MHz handles relay sequencing, keypad scanning, and Modbus-over-UART polling in the same control loop, while the brown-out detector and watchdog timer (WDT) provide the reset integrity required for unattended equipment. The 10-bit ADC with 8 channels digitizes analog sensor inputs such as 0-5V pressure and level transducers directly, eliminating an external ADC IC and its PCB area. Because the part is in-system programmable over SPI, technicians can update firmware through the existing control connector without desoldering, which reduces downtime in panel-mounted controllers. For deployments below -40C or above 70C, drop in the pin-identical industrial-grade ATMEGA16-16PI instead of redesigning the board.
Recommended
Motor Control and PWM Actuation
The ATMEGA16-16PU is well suited to DC and stepper motor control because its four hardware PWM channels (OC0, OC1A, OC1B, OC2) generate phase-correct or fast PWM at frequencies up to the timer clock, giving closed-loop speed control without software timing jitter. The 16-bit Timer/Counter1 supports input capture (ICP1) for reading tachometer pulses, enabling PID speed regulation with measured feedback. Running from a 4.5V to 5.5V rail matches the logic thresholds of common H-bridge and MOSFET gate drivers, and the through-hole 40-PDIP package tolerates the vibration and hand-rework typical of small motor boards. The comparator inputs AIN0/AIN1 (PB2/PB3) add an over-current trip path that can gate the PWM output in hardware for faster fault response than firmware alone. For designs needing complementary PWM outputs for half-bridge drivers, the pin-compatible ATMEGA8535-16PU is a same-footprint alternative.
Recommended
Sensor Interface and Data Logging
For battery-backed loggers and sensor hubs, the ATMEGA16-16PU offers an 8-channel 10-bit ADC, TWI (I2C) and SPI masters for digital sensors, and 512B EEPROM for nonvolatile calibration constants and event counters. The 1KB internal SRAM buffers sampled data before streaming over USART to a host or radio module, and Timer/Counter2 can run in asynchronous mode from a 32.768kHz watch crystal to maintain a real-time clock during sleep. Power-down mode reduces consumption to the microamp class, extending battery life in periodically waking loggers; at the 16MHz 5V grade, active current is higher than newer picoPower parts, so duty-cycle the sleep states aggressively. Designers needing lower sleep current on the same DIP-40 footprint can evaluate the ATMEGA164A-PU, which implements the newer picoPower core while keeping the same pinout.
Recommended
Education and Hobby Embedded Platforms
The ATMEGA16-16PU remains a staple of embedded-systems teaching because the 40-pin DIP is socketable, breadboard-friendly with an adapter, and forgiving of student soldering errors. Its JTAG interface (pins 24-27, PC2-PC5) permits true on-chip breakpoint debugging with inexpensive JTAGICE-class tools, a capability many larger Arduino-style boards lack, which accelerates learning of professional debug workflows. Community toolchains such as the MightyCore Arduino hardware package (MCUdude/MightyCore on GitHub) provide board definitions for ATmega16 and compatible upload via USBasp or Arduino-as-ISP over the SPI ISP pins. The part demonstrates all classic peripherals in one chip: UART for PC communication, SPI and TWI for shields and RTC modules, PWM for servo and LED experiments, and the 10-bit ADC for analog lab exercises, covering a complete embedded curriculum on a single 5V device.
Recommended
Serial Communication Gateways
The ATMEGA16-16PU serves as a compact serial gateway because it provides a full-duplex USART, a hardware SPI master/slave, and a TWI (I2C-compatible) interface, allowing protocol translation between RS-232 field devices, SPI peripherals, and I2C sensors within one 40-pin IC. The USART supports up to 1Mbps at 16MHz, adequate for most industrial polling loops, while hardware flow-control-free buffering plus interrupt-driven firmware sustains reliable throughput. Because all three buses have dedicated pins in the DIP-40 footprint, no software bit-banging is required, improving timing determinism for mixed-protocol bridges such as Modbus RTU to I2C sensor clusters. The 16KB Flash accommodates modest protocol stacks, and designs that outgrow it migrate to the pin-compatible ATMEGA32A-PU for double the code space. For dual independent serial channels, the same-footprint ATMEGA162-16PU adds a second hardware USART.
Recommended
Legacy PCB Maintenance and Repair
The ATMEGA16-16PU is frequently specified for repairing and re-manufacturing legacy equipment because the through-hole 40-pin PDIP survives desoldering cycles and can be socketed for future swaps. Original Atmel-branded units remain available through Rochester Electronics, and current Microchip production continues the same part number, so BOMs do not require requalification. When stock tightens, pin-compatible substitutes such as ATMEGA16A-PU (improved die) and ATMEGA16-16PI (industrial grade) solder directly onto the original land pattern with no board change, and the AVR instruction set is binary compatible across the family, so existing hex firmware programs without recompilation in most cases. This combination of mechanical robustness, long-term supply, and drop-in family migration makes the part a preferred choice for keeping industrial, automotive-test, and medical peripheral legacy boards in service.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA16-16PU β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA16-16PI | ATMEGA16A-PU | ATMEGA32A-PU | ATMEGA8535-16PU | ATMEGA164A-PU | ATMEGA162-16PU |
|---|---|---|---|---|---|---|---|
| Package | 40-PDIP | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16KB | 16KB | 16KB | 32KB | 8KB | 16KB | 16KB |
| SRAM | 1KB | 1KB | 1KB | 2KB | 512B | 1KB | 1KB |
| Max Clock Speed | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 20 MHz | 16 MHz |
| Supply Voltage | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V | 4.5V to 5.5V |
| USART Channels | 1 | 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 | No ADC |
| Firmware Compatibility | Baseline | Binary compatible | Binary compatible | Binary compatible | Recompile recommended | Peripheral register check needed | Pin-mux differences, verify |
Key Differentiators
- 32 I/O lines vs smaller-pin AVRs (vs ATMEGA328P (28-pin DIP))
- Established successor path with identical footprint (vs ATMEGA16A-PU)
- Memory headroom on same footprint (vs ATMEGA32A-PU)
- Trade-off: 5V-only and higher active power (vs ATMEGA164A-PU)
Design Notes
The ATMEGA16-16PU speed grade guarantees 16MHz operation only at 4.5V-5.5V. Decouple VCC (pin 10) and AVCC (pin 30) each with 100nF ceramic capacitors placed within a few millimeters of the pins, plus a 10uF bulk capacitor per board. AVCC should connect to VCC through a low-pass filter (e.g., 10uH inductor or 100-ohm resistor plus capacitor) when the ADC is used, and must never be left floating; if the ADC is unused, tie AVCC directly to VCC. Check brown-out detector fuse settings so the MCU does not execute corrupted code during 5V rail sags.
For the 40-pin DIP, use a socket for maintainability but choose a low-profile machined-pin socket; cheap dual-wipe sockets add contact resistance and long-term reliability risk in vibrating environments. Keep the crystal (up to 16MHz) within 10mm of XTAL1/XTAL2 (pins 12-13) with 22pF load capacitors and a ground guard trace. Route the AREF pin (32) with a 100nF capacitor to ground; never drive it from a high-impedance reference without buffering. The RTC crystal on TOSC1/TOSC2 (pins 28-29) needs its own layout island away from the main crystal.
Four port C pins (PC2-PC5, pins 24-27) are shared with JTAG, which is enabled by default in shipped parts - either program the JTAGEN fuse off to recover the I/O or design your circuit to tolerate JTAG pull-ups. Also note PB2/PB3 (pins 3-4) default to comparator inputs. When migrating firmware to ATMEGA164A-PU, register names and fuse maps differ from the ATmega16; do not assume binary compatibility despite the identical pinout. Finally, erase/program cycles of Flash are rated 10,000 minimum - do not use program Flash for data logging; use the 512B EEPROM instead.
Compliance Information
DigiKey and Mouser listings mark the ATMEGA16-16PU as RoHS compliant; FindMyChip describes the green PDIP variant. REACH, halogen-free, and conflict-minerals status not stated in provided data.
