ATMEGA168PA-PU - 8-bit AVR MCU, 16KB Flash, 20MHz | Microchip
MPN： ATMEGA168PA-PU ✓ 啟用中ATMEGA168PA-PU 概覽
An 8-bit microcontroller (MCU) is a self-contained computing device that integrates a processor core, program memory, data memory, and peripherals on a single silicon die. Within the power management hierarchy of embedded systems, an MCU such as the AVR ATmega family sits at the control layer, executing firmware that coordinates sensors, actuators, and communication interfaces. The AVR architecture uses a modified Harvard layout with 32 general-purpose working registers directly connected to the ALU, allowing most of its 133 instructions to execute in a single clock cycle.
Key features of the ATMEGA168PA-PU include read-while-write ISP Flash programming, 23 general-purpose I/O lines, a 10-bit ADC, a programmable USART, a byte-oriented Two-Wire (I2C) interface, and an SPI serial port. The picoPower technology delivers multiple sleep modes for battery-operated designs, and the -PU suffix denotes the commercial/industrial PDIP (28-DIP, 0.300 inch / 7.62 mm pitch) package supplied in tubes.
Technically, the device operates from a 2.7 V to 5.5 V supply, supports in-system programming via the SPI or bootloader, and includes brown-out detection, a power-on reset, and a watchdog timer for robust operation. Three flexible timer/counters with compare modes and PWM outputs allow motor control, LED dimming, and precise waveform generation without CPU overhead.
Typical applications include Arduino-compatible prototyping boards, hobby and educational electronics, low-power sensor nodes, and small industrial control and instrumentation products where through-hole mounting eases assembly and rework.
For design, note that the 16 KB Flash and 1 KB SRAM ceiling makes the pin-compatible ATMEGA328P-PU (32 KB Flash, 2 KB SRAM) the safer choice if firmware growth is expected; otherwise the ATMEGA168PA-PU offers the lowest cost in the 28-pin family.
This page synthesizes verified distributor data, pin-compatible drop-in alternatives, comparison tables, and practical design notes not found in a single manufacturer datasheet.
直接替換替代品，適用於 ATMEGA168PA-PU — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ATMEGA168PA-PU （相同外形與佔位） — 差異在於 Communication Interfaces, Timers, RoHS Status, Operating Temperature, ADC.
ATMEGA168A-PU
✅ 直接替換📋 參考替代品（不在目錄中）
ATMEGA328P-PU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA168-20PU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA168P-20PU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA168V-10PU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA88PA-PU
✅ 直接替換聯絡詢價
查看資料表 →ATMEGA168PA-PU 最大額定值與電氣特性
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 16 KB (8K x 16) |
| SRAM | 1 KB |
| EEPROM | 512 B |
| 最大時脈頻率 | 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| General Purpose I/O Lines | 23 |
| Working Registers | 32 |
| Instructions | 133, most single-cycle |
| Timers/Counters | 3 (with compare and PWM modes) |
| ADC | 10-bit, 6 channels |
| Communication Interfaces | USART, SPI, Two-Wire (I2C) |
| 封裝 | 28-PDIP (0.300 in, 7.62 mm), through-hole |
| 安裝類型 | Through Hole |
| Packaging | Tube |
| Special Features | picoPower, brown-out detect, POR, watchdog, ISP, read-while-write |
| Life Cycle Stage | Active |
ATMEGA168PA-PU 腳位配置
| 腳位 1 | PC6 / RESET — Reset input (active low) or port C bit 6 |
| 腳位 2 | PD0 / RXD — Port D bit 0 / USART receive |
| 腳位 3 | PD1 / TXD — Port D bit 1 / USART transmit |
| 腳位 4 | PD2 / INT0 — Port D bit 2 / external interrupt 0 |
| 腳位 5 | PD3 / INT1 — Port D bit 3 / external interrupt 1 / OC2B |
| 腳位 6 | PD4 — Port D bit 4 / timer counter input T0/XCK |
| 腳位 7 | VCC — Digital supply voltage (2.7 V to 5.5 V) |
| 腳位 8 | GND — Ground |
| 腳位 9 | PB6 / XTAL1 — Port B bit 6 / crystal oscillator input or external clock |
| 腳位 10 | PB7 / XTAL2 — Port B bit 7 / crystal oscillator output |
| 腳位 11 | PD5 / OC0B — Port D bit 5 / timer0 compare output B / T1 |
| 腳位 12 | PD6 / OC0A — Port D bit 6 / timer0 compare output A / AIN0 |
| 腳位 13 | PD7 / AIN1 — Port D bit 7 / analog comparator negative input |
| 腳位 14 | PB0 / ICP1 — Port B bit 0 / timer1 input capture / CLKO |
| 腳位 15 | PB1 / OC1A — Port B bit 1 / timer1 compare output A |
| 腳位 16 | PB2 / OC1B / SS — Port B bit 2 / timer1 compare output B / SPI slave select |
| 腳位 17 | PB3 / MOSI / OC2A — Port B bit 3 / SPI master output / timer2 compare output A |
| 腳位 18 | PB4 / MISO — Port B bit 4 / SPI master input |
| 腳位 19 | PB5 / SCK — Port B bit 5 / SPI clock |
| 腳位 20 | AVCC — ADC supply voltage, connect to VCC |
| 腳位 21 | AREF — Analog reference voltage for ADC |
| 腳位 22 | GND — Ground |
| 腳位 23 | PC0 / ADC0 — Port C bit 0 / ADC channel 0 |
| 腳位 24 | PC1 / ADC1 — Port C bit 1 / ADC channel 1 |
| 腳位 25 | PC2 / ADC2 — Port C bit 2 / ADC channel 2 |
| 腳位 26 | PC3 / ADC3 — Port C bit 3 / ADC channel 3 |
| 腳位 27 | PC4 / ADC4 / SDA — Port C bit 4 / ADC channel 4 / Two-Wire data |
| 腳位 28 | PC5 / ADC5 / SCL — Port C bit 5 / ADC channel 5 / Two-Wire clock |
典型應用
ATMEGA168PA-PU 適用於 6 應用s: Arduino-Compatible Prototyping Boards, Low-Power Battery Sensor Nodes, Industrial Control and Monitoring, Education and STEM Training Kits, Consumer Appliance Subsystems, Hobby Robotics and RC Projects.
Arduino-Compatible Prototyping Boards
The ATMEGA168PA-PU is the classic through-hole MCU used in early Arduino-compatible boards, because the 28-pin PDIP is socketed and can be swapped in seconds. Its 16 KB Flash runs standard Arduino bootloaders, and its 20 MHz rating (typically clocked at 16 MHz from a ceramic resonator) matches the Arduino ecosystem timing assumptions. The 23 GPIO lines and 10-bit ADC support shields and analog sensors directly. Developers prototype on a socketed DIP, burn the bootloader via ISP, and move to the ATMEGA328P-PU on the same footprint when 16 KB or 1 KB SRAM becomes the limit.
推薦
Low-Power Battery Sensor Nodes
The picoPower technology of the ATMEGA168PA-PU makes it well suited to battery-powered sensor nodes: six sleep modes (idle through power-down) let the design idle at micropower levels and wake on pin-change interrupt, watchdog, or timer event. The 2.7 V floor allows operation directly from two alkaline cells or a single lithium coin cell via a small LDO, while the integrated 10-bit ADC reads temperature, humidity, or light sensors without external converters. A typical node sleeps most of the time, wakes every few seconds, samples a channel, and transmits over USART or SPI - the 16 KB Flash easily holds such firmware.
推薦
Industrial Control and Monitoring
In small industrial controllers, the ATMEGA168PA-PU provides brown-out detection, a power-on reset, and a watchdog timer - the three safety nets required for unattended equipment. Three timer/counters with compare modes generate PWM for motor drives, heater control, or valve positioning, while the USART links to Modbus-style RS-485 transceivers and the Two-Wire interface reads digital sensors. The 5 V rating gives robust noise margins typical of industrial panels, and the through-hole PDIP survives vibration better when socketed with retention clips. Code size for simple sequencer or monitoring tasks stays comfortably within 16 KB Flash and 1 KB SRAM.
推薦
Education and STEM Training Kits
Because the ATMEGA168PA-PU is through-hole and widely documented, it remains a staple of electronics education: students can insert it into a breadboard, wire a 5 V supply and 16 MHz crystal, and flash code with an inexpensive USBasp programmer. The 133-instruction AVR RISC core teaches assembly fundamentals, while the 10-bit ADC, PWM outputs, and USART/SPI/I2C peripherals support progressively advanced labs in sensing, actuation, and serial communication. The 16 KB Flash is ample for classroom exercises, and replacing a damaged chip costs a few dollars - a practical advantage over fragile surface-mount alternatives in teaching environments.
推薦
Consumer Appliance Subsystems
Consumer appliances - coffee makers, fans, small heaters, and chargers - use the ATMEGA168PA-PU for front-panel control: reading buttons via port pins, driving seven-segment or LCD displays, generating buzzer tones with timer PWM, and sequencing relays through GPIO. The 2.7 V to 5.5 V supply range fits transformer or capacitive-dropper power supplies, and the internal RC oscillator removes the crystal in cost-driven designs where timing tolerance permits. The watchdog and brown-out reset ensure the appliance recovers safely from mains brownouts, and the 16 KB Flash holds UI logic, EEPROM-backed user settings (512 B EEPROM), and communication code with ease.
推薦
Hobby Robotics and RC Projects
The ATMEGA168PA-PU is a favorite in hobby robotics for its three timers with PWM outputs that directly drive servo and ESC signals, six ADC channels that read IR rangefinders, line sensors, and battery voltage, and a hardware USART for Bluetooth or telemetry modules over SPI and I2C buses. The 20 MHz capability allows fast control loops for balancing robots, while the 32 working registers let interrupt service routines run with minimal context overhead. The DIP package sockets into perfboard robots, and the wide 2.7 V to 5.5 V range tolerates sagging battery packs during motor stalls.
推薦
推薦產品摘要
工程參考資料，適用於 ATMEGA168PA-PU — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ATMEGA168A-PU | ATMEGA328P-PU | ATMEGA168-20PU | ATMEGA168P-20PU | ATMEGA168V-10PU | ATMEGA88PA-PU |
|---|---|---|---|---|---|---|---|
| Package | 28-PDIP (through-hole) | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 32 KB | 16 KB | 16 KB | 16 KB | 8 KB |
| SRAM | 1 KB | 1 KB | 2 KB | 1 KB | 1 KB | 1 KB | 1 KB |
| Maximum Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz | 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| picoPower Low-Leakage Process | Yes (PA revision) | No | Yes (P revision) | No | Yes | No | Yes (PA revision) |
主要差異化特點
- picoPower low-leakage process for battery designs (對比ATMEGA168A-PU)
- Lowest cost with 16 KB on the 28-pin PDIP footprint (對比ATMEGA328P-PU)
- Full 20 MHz speed rating (對比ATMEGA168V-10PU)
設計說明
Decouple VCC and AVCC separately with 100 nF ceramic capacitors placed as close to pins 7 and 20 as possible, plus 4.7 uF bulk capacitance on the board. AVCC must always be connected to VCC even if the ADC is unused. If ADC accuracy matters, add an RC low-pass (e.g., 10 ohm + 100 nF) between VCC and AVCC and route ADC traces away from clock lines. Estimated: at 5 V and full 20 MHz operation, active current is on the order of 10-15 mA per typical AVR datasheet curves - verify against the current datasheet figure for your voltage and frequency.
PC6 (pin 1) defaults to RESET. If you want a seventh I/O pin, disabling RESET via fuse removes high-voltage ISP reprogrammability - only do this for cost-critical finished products. Also, clock speed is voltage dependent: 16-20 MHz operation requires VCC near 5 V per AVR speed-grade curves; running 16 MHz at 3.3 V is out of specification for this device. When migrating firmware from the ATMEGA328P-PU, check that Flash usage is under 16 KB and static RAM under 1 KB, or the linker will silently overrun SRAM.
Keep the crystal (if used) within a few millimeters of pins 9 and 10 with short ground return paths, and use 12-22 pF load capacitors matched to the crystal specification. Because the PDIP is through-hole, socketed designs add contact resistance and inductance - acceptable at 20 MHz but avoid long ribbon connections to the crystal. For ISP programming, route MOSI, MISO, SCK, and RESET to a 2x3 header, and ensure other circuitry on those pins (e.g., LEDs on SCK) does not load the programming lines.
The PDIP package dissipates far less power than the MCU's rating envelope in typical use. Estimated: at 5 V with ~15 mA active current, dissipation is roughly 75 mW, well within the PDIP thermal capability with no heatsink considerations. Thermal design only becomes relevant when driving high LED or relay currents directly from GPIO - keep per-pin sink/source current within datasheet absolute maximum ratings (40 mA absolute maximum per pin, lower for reliable long-term operation) and use transistors or drivers for loads above a few tens of milliamperes.
合規資訊
Compliance details were not stated in the provided web data; consult the Microchip product page or environmental datasheet. Note that ATMEGA168-20PU listings describe a 'green' variant of the older family.
