ATMEGA168PB-AU - 8-Bit AVR MCU, 20MHz, 16KB Flash | Microchip
MPN: ATMEGA168PB-AU ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.74 | $1.74 |
| 10 | $1.6 | $16.00 |
| 100 | $1.45 | $145.00 |
| 500 | $1.35 | $675.00 |
| 1,000 | $1.27 | $1,270.00 |
ATMEGA168PB-AU Overview
An 8-bit AVR microcontroller is a single-chip computer built on the AVR enhanced RISC architecture, in which most instructions execute in a single clock cycle. As a member of the broader microcontroller hierarchy (MCU -> embedded processor -> semiconductor device), it integrates flash program memory, SRAM data memory, EEPROM non-volatile storage, peripherals, and a CPU core in one package, replacing multi-chip solutions in cost- and power-sensitive embedded systems.
Key differentiating features include 16 KB of self-programmable ISP flash with read-while-write capability, two 8-bit and one 16-bit timer/counters, a 10-bit ADC, and the picoPower technology that minimizes consumption in sleep modes. The 27 general-purpose I/O lines and 32 general-purpose working registers support efficient C-compiler code generation.
The AVR Harvard architecture accesses program and data memory simultaneously, achieving near 1 MIPS/MHz efficiency. Six sleep modes, an on-chip debug interface, and in-system programming via SPI round out the system-level feature set, while the PB variant refines the pin configuration relative to earlier ATmega48/88/168 versions (see Microchip application note AT06609).
Typical applications include industrial control and automation nodes, consumer appliances, battery-powered portable instruments, and hobby/education platforms such as Arduino-compatible boards. The wide 1.8V to 5.5V operating range fits both lithium-cell and 5V industrial rails.
Design consideration: verify pin mappings against AT06609 when migrating from ATmega168PA/168A layouts, and plan ISP header access for in-system firmware updates.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and migration guidance not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA168PB-AU — 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 ATMEGA168PB-AU (same form factor and footprint) — differing in Operating Temperature, Package, RoHS Status, Core Architecture, Serial Interfaces.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA168PA-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$0.98 / Unit
View Datasheet →ATMEGA168P-20AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.91 / Unit
View Datasheet →ATMEGA168A-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.42 / Unit
View Datasheet →ATMEGA168PA-MU
✅ Drop-In✓ In Stock
$1.72 / Unit
View Datasheet →ATMEGA168PB-AU Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 16 KB (8K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| General Purpose I/O | 27 lines |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Package | TQFP-32 (7x7 mm) |
| Mounting Type | Surface Mount |
| Throughput | Up to 20 MIPS (approx. 1 MIPS per MHz) |
| ADC | 10-bit ADC |
| Timers | 2 x 8-bit, 1 x 16-bit |
| Programming Interface | ISP (SPI), self-programmable flash |
| Sleep Modes | picoPower, 6 sleep modes |
| Working Registers | 32 general-purpose registers |
| Functional Safety | FuSa supported variant family |
| RoHS Status | Compliant (RoHS, per LCSC listing) |
| ECCN | EAR99 |
ATMEGA168PB-AU Pin Configuration
| Pin 1 | PC6/RESET — Port C bit 6 / Reset input |
| Pin 2 | PD0/RXD — Port D bit 0 / USART receive |
| Pin 3 | PD1/TXD — Port D bit 1 / USART transmit |
| Pin 4 | PD2/INT0 — Port D bit 2 / External interrupt 0 |
| Pin 5 | PD3/INT1/OC2B — Port D bit 3 / External interrupt 1 / Timer2 output compare B |
| Pin 6 | PD4/T0/XCK — Port D bit 4 / Timer0 external clock / USART external clock |
| Pin 7 | VCC — Digital supply voltage |
| Pin 8 | GND — Ground |
| Pin 9 | PB6/XTAL1/TOSC1 — Port B bit 6 / Crystal oscillator pin 1 |
| Pin 10 | PB7/XTAL2/TOSC2 — Port B bit 7 / Crystal oscillator pin 2 |
| Pin 11 | PD5/T1/OC0B — Port D bit 5 / Timer1 external clock / Timer0 output compare B |
| Pin 12 | PD6/AIN0/OC0A — Port D bit 6 / Analog comparator positive input / Timer0 output compare A |
| Pin 13 | PD7/AIN1 — Port D bit 7 / Analog comparator negative input |
| Pin 14 | PB0/ICP1/CLKO — Port B bit 0 / Timer1 input capture / Clock output |
| Pin 15 | PB1/OC1A — Port B bit 1 / Timer1 output compare A |
| Pin 16 | PB2/SS/OC1B — Port B bit 2 / SPI slave select / Timer1 output compare B |
| Pin 17 | PB3/MOSI/OC2A — Port B bit 3 / SPI master out / Timer2 output compare A |
| Pin 18 | PB4/MISO — Port B bit 4 / SPI master in |
| Pin 19 | PB5/SCK — Port B bit 5 / SPI clock |
| Pin 20 | AVCC — ADC supply voltage |
| Pin 21 | AREF — ADC analog reference |
| Pin 22 | GND — Ground |
| Pin 23 | PC0/ADC0 — Port C bit 0 / ADC channel 0 |
| Pin 24 | PC1/ADC1 — Port C bit 1 / ADC channel 1 |
| Pin 25 | PC2/ADC2 — Port C bit 2 / ADC channel 2 |
| Pin 26 | PC3/ADC3 — Port C bit 3 / ADC channel 3 |
| Pin 27 | PC4/ADC4/SDA — Port C bit 4 / ADC channel 4 / TWI data |
| Pin 28 | PC5/ADC5/SCL — Port C bit 5 / ADC channel 5 / TWI clock |
| Pin 29 | PC6/RESET* — Alternate reset / port function (per PB family pin map - verify against datasheet DS40001909B) |
| Pin 30 | PD0* — Alternate port function (per PB family pin map - verify against datasheet DS40001909B) |
| Pin 31 | PD1* — Alternate port function (per PB family pin map - verify against datasheet DS40001909B) |
| Pin 32 | PD2* — Alternate port function (per PB family pin map - verify against datasheet DS40001909B) |
Typical Applications
ATMEGA168PB-AU is suitable for 6 applications: Industrial Control and Automation Nodes, Battery-Powered Portable Instruments, Arduino-Compatible Education and Hobby Platforms, Consumer Appliance Control Boards, Sensor Interface and Data Acquisition Modules, IoT Edge Sensor Nodes.
Industrial Control and Automation Nodes
The ATMEGA168PB-AU suits industrial control nodes because its 20 MHz AVR core delivers up to 20 MIPS of deterministic single-cycle RISC execution, while the 27 GPIO lines and 10-bit ADC interface sensors, relays, and actuators directly. The 1.8V to 5.5V supply range tolerates unregulated industrial rails with a simple LDO front end, and the FuSa-supported family classification eases documentation for safety-relevant subsystems. In a typical node, the MCU polls sensors via the ADC and I2C/SPI peripherals, drives status outputs, and communicates over UART to a supervisory controller, with the 512 B EEPROM retaining calibration data across power cycles.
Recommended
Battery-Powered Portable Instruments
picoPower technology makes the ATMEGA168PB-AU well suited to battery-operated meters and loggers: six sleep modes let designers cut quiescent draw to microamp levels between 20 MHz active bursts. Running from 2x AA cells (1.8V-3.0V end-of-life) or a single lithium coin cell, the wide 1.8V to 5.5V operating window eliminates boost converters in many designs. The 10-bit ADC samples analog front ends directly, while timer peripherals generate precision wake-up intervals. A typical handheld instrument spends most of its life in power-down sleep, waking on interrupt to sample, log to EEPROM or UART, and return to sleep, extending battery life from months to years.
Recommended
Arduino-Compatible Education and Hobby Platforms
The ATMEGA168PB-AU is an economical engine for Arduino-compatible boards. It shares the ATmega328P's core architecture, so standard AVR toolchains and the community MiniCore package support it directly, and its 16 KB flash hosts most educational sketches. At roughly half the cost of a 328P, it reduces board BOM for classroom kits and maker products sold in volume. The TQFP-32 (7x7 mm) package suits compact board designs with the classic 2x3 ISP header for bootloader burning. Typical use cases include line-following robots, sensor shields, and IoT starter kits where 16 KB flash and 1 KB SRAM are sufficient headroom.
Recommended
Consumer Appliance Control Boards
White-goods and small-appliance control boards benefit from the ATMEGA168PB-AU's cost-effective integration: one chip replaces discrete logic, timers, and analog comparators. The three timer/counters (two 8-bit, one 16-bit) generate PWM for motor speed control and heater phase-angle control, while the 10-bit ADC reads temperature sensors (NTC) and user potentiometers. The wide 1.8V-5.5V supply range simplifies mains-derived auxiliary supplies, and the 512 B EEPROM stores user settings and fault logs through power interruptions. The 20 MHz clock with single-cycle instructions gives responsive button handling and accurate timing without an external real-time chip in many designs.
Recommended
Sensor Interface and Data Acquisition Modules
The ATMEGA168PB-AU functions as a compact DAQ front end: its 10-bit ADC with internal reference digitizes up to several kSPS from thermistors, potentiometers, and bridge sensors, while SPI and I2C masters interface external precision ADCs and digital sensors. The 1 KB SRAM buffers sample blocks for burst transfer over UART to a host, and hardware CRC-enhanced USART links keep serial data integrity high. Because flash is self-programmable with read-while-write, firmware can log calibration data into its own program region or support field updates via a UART bootloader, reducing service cost in installed sensor nodes deployed across a factory floor or building.
Recommended
IoT Edge Sensor Nodes
For battery-powered IoT edge nodes, the ATMEGA168PB-AU acts as the ultra-low-power sensor controller paired with a radio module such as an ESP8266 or LoRa transceiver. The MCU sleeps in power-down mode between wake cycles, samples the environment with its 10-bit ADC or I2C sensors, and forwards packetized readings over UART to the radio, which handles the network stack. This division of labor lets the picoPower AVR run for months on primary cells while the radio draws current only during transmissions. The 27 GPIO lines manage interrupts, sensor power gating, and LED status, and the 512 B EEPROM stores device IDs and calibration constants.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168PB-AU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168PA-AU | ATMEGA168P-20AU | ATMEGA168A-AU |
|---|---|---|---|---|
| Package | TQFP-32 (7x7) | TQFP-32 (7x7) - same | TQFP-32 (7x7) - same | TQFP-32 (7x7) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 16 KB | 16 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Pin Function Differences | Reference (PB die) | Minor changes vs PB (app note AT06609) | Earlier revision, verify AT06609 | Earlier revision, verify AT06609 |
Key Differentiators
- Latest PB die revision with Functional Safety (FuSa) support (vs ATMEGA168A-AU)
- picoPower low-sleep-current technology (vs ATMEGA168P-20AU)
- Same footprint across all ATmega168 revisions enables layout reuse (vs ATMEGA168PA-AU)
Design Notes
Connect AVCC (pin 20) to VCC through a low-pass RC network (e.g., 10 ohm + 100 nF) even when the ADC is unused - the datasheet requires AVCC within 0.3V of VCC for correct operation. Place a 100 nF ceramic decoupling capacitor directly across VCC (pin 7) and GND (pin 8), and another at AREF only if the internal reference or an external reference is used. Keep the crystal (PB6/PB7) traces short and guard them with ground pour for reliable 20 MHz operation.
When migrating from ATmega168PA/168A to the PB die, do not assume full pin-function identity: Microchip application note AT06609 documents alternate pin configurations and peripheral mapping changes. Verify every peripheral-to-pin assignment in your schematic and firmware pin definitions. Also note PC6/RESET must not be driven high above VCC tolerance; use a 10 k pull-up and optional external reset supervisor rather than hard-driving the pin.
Estimated: with a 5V supply at 20 MHz active mode, typical AVR active current is on the order of a few mA (per datasheet electrical characteristics), so an ATMEGA168PB-AU node dissipates roughly 15-25 mW - no thermal design is needed. For battery designs, exploit the six sleep modes: power-down sleep current is in the microamp class; wake on pin-change or watchdog interrupt and keep active bursts short to average consumption below 100 uA.
Reserve a standard 2x3 (0.1 inch) ISP header wired to PB3/MOSI, PB4/MISO, PB5/SCK, RESET, VCC, and GND. Keeping these traces short and away from switching-node sources (motor drivers, triac circuits) prevents both flashing failures and corruption during in-system programming. If using a UART bootloader instead, ensure the bootloader lock-bit region is sized to leave adequate application flash of the 16 KB total.
Compliance Information
RoHS compliant per LCSC listing (C194438); Mouser describes the package as 'TQFP GRN' (green/lead-free). REACH and conflict-minerals status not stated in provided data.
