ATMEGA168P-20AUR - 8-bit AVR MCU 16KB Flash 20MHz | Microchip
MPN: ATMEGA168P-20AUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.32 | $4.32 |
| 10 | $3.89 | $38.90 |
| 100 | $2.61 | $261.00 |
| 500 | $2.09 | $1,045.00 |
| 1,000 | $1.49 | $1,490.00 |
ATMEGA168P-20AUR Overview
An 8-bit AVR microcontroller is a single-chip computer built around the AVR enhanced RISC architecture, in which most of the 131 powerful instructions execute in a single clock cycle. Within the power-management hierarchy, an MCU integrates a processor core, program flash, data SRAM, EEPROM, and peripherals such as timers, UART, SPI, I2C, and a 10-bit ADC on one die, replacing multi-chip solutions in embedded control systems.
Key differentiating specifications include the picoPower technology for ultra-low sleep-mode consumption, an 8-channel 10-bit ADC, in-system self-programmable flash with read-while-write support, debugWIRE on-chip debugging, and an industrial temperature rating of -40C to +85C. The 20 MHz maximum clock and 5 V operation position this part between the low-speed 8 MHz variants and higher-memory ATmega328P devices.
Architecturally, the ATmega168P pairs a fast-register-file RISC core (32 general-purpose working registers directly connected to the ALU) with Harvard-structured program and data buses. Two-cycle multiply hardware, three flexible timers with compare and PWM modes, a USART, and independent brown-out reset and watchdog circuits yield deterministic real-time behavior with minimal external components.
Typical applications include hobby and commercial Arduino-compatible boards, industrial sensor nodes and actuator control, consumer appliance front panels, battery-powered instrumentation, and motor/PWM control loops. The picoPower feature set makes it especially well suited to battery-operated designs requiring microamp-level sleep currents.
A key design consideration is supply-voltage versus clock-speed derating: above 8 MHz the device requires 4.5 V to 5.5 V operation, so a 3.3 V design must be clocked at 8 MHz or below per the manufacturer datasheet speed-versus-voltage curve.
This page synthesizes verified distributor pricing, drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet, delivering unique cross-reference value for sourcing and design engineers. Pricing references are as of 2026-09-16.
Drop-in alternatives for ATMEGA168P-20AUR — 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 ATMEGA168P-20AUR (same form factor and footprint) — differing in Package, ADC Resolution, Serial Interfaces, Operating Temperature, EEPROM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA168PA-AUR
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →ATMEGA168-20AU
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →ATMEGA168A-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.42 / Unit
View Datasheet →ATMEGA328P-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.85 / Unit
View Datasheet →ATMEGA88-20AU
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA48-20AUR
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA168P-20AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Memory | 16 KB (8K x 16) ISP |
| SRAM | 1 KB |
| EEPROM | 512 B |
| Maximum Clock Frequency | 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Number of I/O Lines | 23 |
| ADC Resolution | 10 bit |
| ADC Channels | 8 (TQFP/QFN packages) |
| Communication Interfaces | USART, SPI, I2C (TWI) |
| Timers | 2 x 8-bit, 1 x 16-bit |
| PWM Channels | Yes (timer compare outputs) |
| Debug Interface | debugWIRE on-chip debugging |
| Programming | In-Circuit Serial Programming (ICSP) |
| Low Power Technology | picoPower |
| Operating Temperature | -40C to +85C |
| Package | 32-TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| Lifecycle Status | Active |
ATMEGA168P-20AUR Pin Configuration
| Pin 1 | PD3 — Port D bit 3 (PCINT19/OC2B/INT1) |
| Pin 2 | PD4 — Port D bit 4 (PCINT20/XCK/T0) |
| Pin 3 | GND — Ground |
| Pin 4 | VCC — Digital supply voltage |
| Pin 5 | GND — Ground |
| Pin 6 | VCC — Digital supply voltage |
| Pin 7 | PB6 — Port B bit 6 (PCINT6/XTAL1/TOSC1) - crystal input |
| Pin 8 | PB7 — Port B bit 7 (PCINT7/XTAL2/TOSC2) - crystal output |
| Pin 9 | PD5 — Port D bit 5 (PCINT21/OC0B/T1) |
| Pin 10 | PD6 — Port D bit 6 (PCINT22/OC0A/AIN0) |
| Pin 11 | PD7 — Port D bit 7 (PCINT23/AIN1) |
| Pin 12 | PB0 — Port B bit 0 (PCINT0/CLKO/ICP1) |
| Pin 13 | PB1 — Port B bit 1 (PCINT1/OC1A) |
| Pin 14 | PB2 — Port B bit 2 (PCINT2/SS/OC1B) |
| Pin 15 | PB3 — Port B bit 3 (PCINT3/OC2A/MOSI) |
| Pin 16 | PB4 — Port B bit 4 (PCINT4/MISO) |
| Pin 17 | PB5 — Port B bit 5 (PCINT5/SCK) |
| Pin 18 | AVCC — ADC supply voltage |
| Pin 19 | ADC6 — ADC input channel 6 (TQFP/QFN only) |
| Pin 20 | AREF — Analog reference voltage |
| Pin 21 | GND — Ground |
| Pin 22 | ADC7 — ADC input channel 7 (TQFP/QFN only) |
| Pin 23 | PC0 — Port C bit 0 (ADC8/PCINT8) |
| Pin 24 | PC1 — Port C bit 1 (ADC9/PCINT9) |
| Pin 25 | PC2 — Port C bit 2 (ADC10/PCINT10) |
| Pin 26 | PC3 — Port C bit 3 (ADC11/PCINT11) |
| Pin 27 | PC4 — Port C bit 4 (ADC12/SDA/PCINT12) - I2C data |
| Pin 28 | PC5 — Port C bit 5 (ADC13/SCL/PCINT13) - I2C clock |
| Pin 29 | PC6 — Port C bit 6 (RESET/PCINT14) - active-low reset |
| Pin 30 | PD0 — Port D bit 0 (RXD/PCINT16) - UART receive |
| Pin 31 | PD1 — Port D bit 1 (TXD/PCINT17) - UART transmit |
| Pin 32 | PD2 — Port D bit 2 (PCINT18/INT0) |
Typical Applications
ATMEGA168P-20AUR is suitable for 6 applications: Arduino-Compatible and Hobby Boards, Industrial Sensor Nodes, Battery-Powered Portable Devices, Motor Control and PWM Actuation, Home Automation and IoT Endpoints, Consumer Appliance Control Panels.
Arduino-Compatible and Hobby Boards
The ATMEGA168P-20AUR is the classic 8-bit AVR heart of Arduino-compatible boards: it runs the Arduino bootloader on its 16 KB ISP flash and exposes 23 I/O lines matching the documented ATmega168/328 Arduino pin mapping. Per Microchip, ICSP programming via MPLAB SNAP uses only two I/O pins plus RESET, so a standard 6-pin header preserves both bootloading and debugWIRE debugging. At a 16 MHz external crystal and 5 V rail, the core delivers 16 MIPS with single-cycle execution of most instructions. The main trade-off versus the ATmega328P is 16 KB versus 32 KB flash, which constrains larger sketches and bootloader size, making the 328P preferable when sketch complexity grows.
Recommended
Industrial Sensor Nodes
In industrial sensing and monitoring nodes, the ATMEGA168P-20AUR pairs its 8-channel 10-bit ADC directly with analog sensors such as thermistors, pressure bridges, and 4-20 mA front ends, sampling up to about 15 kSPS at full resolution. The industrial -40C to +85C temperature range and 2.7-5.5 V supply tolerance support 24 V-rail designs via simple regulation, while brown-out detection and the watchdog timer provide autonomous fault recovery in unattended installations. picoPower sleep modes drop consumption to microamp levels for battery-backed data loggers. The USART and SPI interfaces connect to RS-485 transceivers or external flash for data buffering, and the 512 B EEPROM stores calibration coefficients across power cycles without external non-volatile memory.
Recommended
Battery-Powered Portable Devices
Battery-operated meters, remote controls, and wearables benefit from the ATMEGA168P-20AUR's picoPower feature set: power-down sleep modes reduce supply current to sub-microamp levels while the asynchronous timer keeps an RTC counting, and pin-change interrupts wake the core on button presses or sensor events. Running from two AA cells (nominal 3 V) is feasible with an 8 MHz or internal 1 MHz clock, since the device operates down to 2.7 V per distributor datasheet data. The 10-bit ADC enables battery-voltage supervision, and the 512 B EEPROM preserves user settings across battery replacement. Designers should budget sleep/wake latency and use sleep-heavy duty cycles; a coin-cell design benefits from the ATMEGA168PA-AUR's further-reduced consumption in the same footprint.
Recommended
Motor Control and PWM Actuation
The ATMEGA168P-20AUR generates PWM from its three timers - two 8-bit and one 16-bit - offering phase-correct and fast PWM modes with configurable prescalers, sufficient for DC motor speed control, servo positioning, and LED dimming at 8- or 10-bit resolution. The 16-bit timer supports input capture for tachometer feedback, closing speed loops in firmware. At 20 MHz and 5 V, the core delivers 20 MIPS of control bandwidth, and 23 I/O lines drive H-bridge gates through MOSFET driver ICs. Per Microchip application practice, pair the MCU with a gate driver rather than driving power MOSFETs directly, and use the ADC to monitor motor current via a shunt for stall detection and overcurrent protection.
Recommended
Home Automation and IoT Endpoints
As a connected endpoint, the ATMEGA168P-20AUR handles protocol bridging and local control: its hardware USART, SPI, and I2C/TWI interfaces connect directly to Wi-Fi or sub-GHz modules and sensor clusters without bit-banging overhead. The 16 KB flash accommodates a control application plus a lightweight serial protocol stack, while 23 I/O lines drive relays, triacs, and status indicators. In 3.3 V smart-home designs, clock the device at 8 MHz to satisfy the voltage-speed derating curve and achieve direct 3.3 V logic compatibility with radio modules. picoPower idle modes allow always-on presence detection at modest average current; for strict energy budgets, choose the ATMEGA168PA-AUR drop-in. A watchdog plus brown-out reset ensures autonomous recovery after radio-module brownouts.
Recommended
Consumer Appliance Control Panels
Appliance front panels - ovens, air conditioners, coffee machines - use the ATMEGA168P-20AUR to scan keypads, drive multiplexed seven-segment or LCD displays, and manage buzzer feedback from its timer PWM outputs. The 10-bit ADC reads NTC temperature sensors and user potentiometers, while the 512 B EEPROM retains user preferences and cycle counters across power interruptions. The -40C to +85C industrial grade and internal brown-out reset tolerate mains-sag conditions common in appliance environments. Running at 5 V with an 8-16 MHz crystal gives ample headroom for display refresh and debouncing within one main-loop iteration. Its low unit cost at 1000-piece volume (about $1.49 as of 2026-09-16) fits high-volume appliance BOM targets.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168P-20AUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168PA-AUR | ATMEGA168-20AU | ATMEGA328P-AU | ATMEGA88-20AU | ATMEGA48-20AUR |
|---|---|---|---|---|---|---|
| Package | 32-TQFP (7x7 mm) | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 16 KB | 32 KB | 8 KB | 4 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 2 KB | 1 KB | 512 B |
| EEPROM | 512 B | 512 B | 512 B | 1 KB | 512 B | 256 B |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Power Technology | picoPower (P variant) | picoPower (PA, lowest power) | Standard (non-picoPower) | picoPower (P variant) | Standard | Standard |
| ADC Channels (10-bit) | 8 | 8 | 8 | 8 | 8 | 8 |
| Operating Temperature | -40C to +85C | -40C to +85C | 0C to +70C (commercial) | -40C to +85C | 0C to +70C (commercial) | 0C to +70C (commercial) |
Key Differentiators
- picoPower die with full 20 MHz rating (vs ATMEGA168-20AU)
- Cost-optimized 16 KB flash tier (vs ATMEGA328P-AU)
- Industrial temperature grade (vs ATMEGA48-20AUR)
- Same footprint path to lower power (vs ATMEGA168PA-AUR)
Design Notes
Respect the AVR speed-versus-voltage derating curve: the ATMEGA168P-20AUR is specified at 2.7 V to 5.5 V, but the full 20 MHz clock rating requires roughly 4.5 V to 5.5 V. A 3.3 V design must be limited to 8 MHz or less. Decouple both VCC pins (pins 4 and 6) with 100 nF ceramic capacitors placed within 5 mm of each pin, and decouple AVCC (pin 18) separately, connecting it to VCC through a low-pass LC filter (10 uH + 100 nF) when ADC accuracy matters. Enable brown-out detection at 2.7 V to prevent EEPROM corruption during brownouts.
Keep the analog ground and digital ground as a single plane with careful placement rather than split planes: route the ADC input traces (PC0-PC5, ADC6, ADC7) away from crystal and UART switching lines. Place the 16 MHz crystal within 10 mm of PB6/PB7 with short return traces and 22 pF load capacitors tuned to the crystal spec. Reserve an unpopulated 6-pin ICSP header (MOSI, MISO, SCK, RESET, VCC, GND) so field programming with MPLAB SNAP or an ISP programmer is possible without disassembly - per Microchip this uses two I/O pins plus RESET.
The device ships with CKDIV8 fuse programmed, so a fresh ATMEGA168P-20AUR runs at 1 MHz from the internal 8 MHz RC oscillator - code written for a 16 MHz crystal will time out at 1/16 speed until fuses are set. RESET (PC6) is by default a reset input; do not repurpose it to I/O unless debugWIRE is disabled first, or you will lock out ISP programming. Also note that driving RESET low disables the debugWIRE interface. Verify errata for the specific flash revision from Microchip before relying on edge-case peripheral behaviors.
Estimated: at 5 V, 20 MHz active mode with typical 20 mA-plus-I/O supply current (say 25 mA total with loaded outputs), power dissipation is about 0.125 W. The 32-TQFP 7x7 mm junction-to-ambient resistance is on the order of 60-100 C/W (typical for this package), so junction rise is only about 8-12 C over ambient - no heatsinking is needed. Thermal design only becomes a concern if many I/O pins source heavy DC loads simultaneously; keep per-port drive current within datasheet absolute-maximum limits.
Compliance Information
RoHS compliant and lead-free per current distributor listings (LCSC, DigiKey). REACH, halogen-free, and conflict-minerals declarations not stated in provided data - obtain formal certificates from Microchip compliance documentation.