ATMEGA168PA-PN - 8-bit AVR MCU 16KB Flash PDIP-28 | Microchip
MPN: ATMEGA168PA-PN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.12 | $3.12 |
| 10 | $2.78 | $27.80 |
| 100 | $2.41 | $241.00 |
| 500 | $2.15 | $1,075.00 |
| 1,000 | $1.94 | $1,940.00 |
ATMEGA168PA-PN Overview
An 8-bit microcontroller (MCU) integrates a processor core, memory, and peripherals on a single chip, sitting at the device level of the embedded-systems hierarchy below SoCs and above discrete logic. The AVR architecture uses a Harvard design with 131 powerful instructions, most executing in a single clock cycle, and 32 x 8-bit general-purpose working registers that are directly connected to the ALU, delivering up to 20 MIPS throughput at 20 MHz.
Key features include 16KB self-programmable Flash with real Read-While-Write capability, an 8-channel 10-bit ADC sampling at up to 15 kSPS, one USART, one SPI, one TWI (I2C) interface, two 8-bit timers and one 16-bit timer with compare modes, plus picoPower technology for ultra-low sleep-mode consumption. The -PN suffix denotes the industrial temperature range PDIP packaging.
The picoPower ATmega PA generation uses a low-leakage process and advanced sleep modes (Idle, ADC Noise Reduction, Power-save, Power-down, Standby) that let battery designs spend most of their life in microwatt-level Power-down while waking via interrupt in microseconds.
Typical applications include Arduino-compatible prototype boards, industrial sensors and relay controllers, battery-powered instruments, and educational/embedded training platforms - the PDIP package is ideal for hand assembly, sockets, and breadboarding.
Design consideration: PDIP-28 has higher package parasitics than QFN/MU variants, so keep system clocks at or below 16 MHz for external-crystal designs and always decouple both VCC pins with 100 nF ceramics.
This page adds distributor pricing tiers, verified drop-in alternatives, complete pinout, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA168PA-PN — 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 ATMEGA168PA-PN (same form factor and footprint) — differing in ADC, Communication Interfaces, Package, Working Registers, Supply Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA168PA-PU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.86 / Unit
View Datasheet →ATMEGA168-20PU
✅ Drop-In✓ In Stock
$3.78 / Unit
View Datasheet →ATMEGA328P-PU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
Contact for price
View Datasheet →ATMEGA88PA-PN
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA168PA-PN Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Data Bus Width | 8 bit |
| Maximum Clock Frequency | 20 MHz |
| Program Memory Size | 16 KB (8K x 16) Flash |
| SRAM Size | 1 KB |
| EEPROM Size | 512 B |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Supply Voltage Grades | 2.5V / 3.3V / 5V capable per FindIC listing |
| Instructions | 131 instructions, most single-cycle |
| General Purpose Working Registers | 32 x 8 |
| General Purpose I/O Lines | 23 |
| ADC | 10-bit, 15 kSPS, 8 channels |
| Communication Interfaces | 1x USART, 1x SPI, 1x TWI (I2C) |
| Timers | 2x 8-bit, 1x 16-bit |
| Package Type | 28-PDIP |
| Mounting Type | Through Hole |
| Programming/Debug | ICSP (In-Circuit Serial Programming) |
| Life Cycle Stage | Active |
| RoHS Status | Compliant |
ATMEGA168PA-PN Pin Configuration
| Pin 1 | PC6 / RESET — Reset input (active low) / I/O |
| 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 PWM output |
| Pin 6 | PD4 / T0 / XCK — Port D bit 4 / Timer0 external clock / USART external clock |
| Pin 7 | VCC — Digital supply voltage (2.7V to 5.5V) |
| Pin 8 | GND — Ground |
| Pin 9 | PB6 / XTAL1 / TOSC1 — Port B bit 6 / crystal oscillator input |
| Pin 10 | PB7 / XTAL2 / TOSC2 — Port B bit 7 / crystal oscillator output |
| Pin 11 | PD5 / T1 / OC0B — Port D bit 5 / Timer1 external clock / Timer0 PWM output |
| Pin 12 | PD6 / AIN0 / OC0A — Port D bit 6 / analog comparator positive input / Timer0 PWM output |
| Pin 13 | PD7 / AIN1 — Port D bit 7 / analog comparator negative input |
| Pin 14 | PB0 / ICP1 / CLK0 — Port B bit 0 / Timer1 input capture / divided system clock output |
| Pin 15 | PB1 / OC1A — Port B bit 1 / Timer1 PWM output A |
| Pin 16 | PB2 / SS / OC1B — Port B bit 2 / SPI slave select / Timer1 PWM output B |
| Pin 17 | PB3 / MOSI / OC2A — Port B bit 3 / SPI master data out / Timer2 PWM output |
| Pin 18 | PB4 / MISO — Port B bit 4 / SPI master data in |
| Pin 19 | PB5 / SCK — Port B bit 5 / SPI serial clock |
| Pin 20 | AVCC — ADC supply voltage (connect to VCC) |
| Pin 21 | AREF — ADC analog reference input |
| 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 |
Typical Applications
ATMEGA168PA-PN is suitable for 6 applications: Arduino-Compatible Prototype Boards, Industrial Sensor Nodes and Relay Controllers, Battery-Powered Portable Instruments, Embedded Education and Training Platforms, Consumer Appliance Control Panels, Retro and Repair-Friendly Designs.
Arduino-Compatible Prototype Boards
The ATMEGA168PA-PN is the historical heart of Arduino-class boards: its 28-pin PDIP fits a standard socket, letting makers swap or re-flash the MCU in seconds via the 6-pin ICSP header (PB3/MOSI, PB4/MISO, PB5/SCK, PC6/RESET). With 16KB Flash, 1KB SRAM, and a 16 MHz typical crystal, it runs the Arduino bootloader and handles typical sketches within roughly 14KB of usable program space. Its 23 GPIO and built-in 10-bit ADC interface directly with shields and analog sensors. Engineers choose the PDIP form over SMD variants during development because hand soldering, socketing, and rework are trivial, then migrate to ATMEGA168PA-MU for production volumes.
Recommended
Industrial Sensor Nodes and Relay Controllers
In factory automation, the ATMEGA168PA-PN serves as a compact sensor-to-actuator controller: the 8-channel 10-bit ADC (15 kSPS) digitizes analog transducers, the TWI (I2C) and SPI buses read digital sensors and expansion ICs, and 23 GPIO drive relays, indicators, and optocoupler inputs. The industrial-grade -PN part operates from a 5V rail common on PLC backplanes (2.7V-5.5V supply range). PicoPower sleep modes let battery-backed nodes duty-cycle between measurements, while the watchdog timer and brown-out detector add fault resilience required in 24/7 installations. PDIP packaging also simplifies field replacement in control cabinets.
Recommended
Battery-Powered Portable Instruments
The picoPower ATmega168PA generation is engineered for energy-constrained designs. In Power-down mode the core stops while the watchdog, pin-change, or TWI-address interrupts remain armed, letting a two-cell battery instrument sleep for months between events and wake in microseconds. The 2.7V minimum supply supports lithium coin cells through an LDO or direct 3V operation at reduced clock speed. On the ATMEGA168PA-PN, the 512B EEPROM retains calibration coefficients across battery changes without external NVRAM. Designers trade peak 20 MHz throughput for voltage-scaled operation, matching the frequency-versus-VCC curve in the datasheet to maximize efficiency.
Recommended
Embedded Education and Training Platforms
Universities and training labs favor the ATMEGA168PA-PN because the 0.1-inch-pitch PDIP survives repeated insertion into breadboards and ZIF programmers. Students access every documented peripheral - USART for serial labs, SPI and TWI for peripheral interfacing, timers for PWM motor control, and the 10-bit ADC for analog coursework - using the free AVR-GCC toolchain and Microchip Studio IDE. The 131-instruction single-cycle RISC core makes assembly-language teaching practical, and ICSP over the standard 6-pin header lets any low-cost USBasp programmer flash devices. No surface-mount skills are needed, lowering the entry barrier for first-year courses.
Recommended
Consumer Appliance Control Panels
Microwave panels, coffee machines, and HVAC thermostats use ATmega-class MCUs where a 5V logic rail, low BOM cost, and robust I/O matter more than processing muscle. The ATMEGA168PA-PN scans keypads via PC0-PC5/PD port pins, drives seven-segment or LED matrices with timer PWM, and communicates over TWI to display drivers. Its industrial temperature tolerance and wide 2.7V-5.5V supply tolerate mains-supply sag, while the brown-out detector prevents corrupt EEPROM writes during brownouts. The through-hole PDIP also suits low-volume, hand-assembled appliance control boards where automated SMT lines are not economical.
Recommended
Retro and Repair-Friendly Designs
Repairable and legacy-support equipment increasingly specifies socketed PDIP microcontrollers so field technicians can replace failed ICs with a screwdriver rather than reflow equipment. The ATMEGA168PA-PN fits 28-pin DIP sockets used across two decades of AVR designs: ATMEGA8, ATMEGA88, ATMEGA168, and ATMEGA328 share this footprint and pinout, enabling drop-in family upgrades (for example, a 168PA replacing an ATMEGA8 board with minor code changes for the doubled register set). The 16KB Flash covers bootloader plus application in legacy firmware, and self-programming supports in-field firmware updates over USART.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168PA-PN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168PA-PU | ATMEGA168-20PU | ATMEGA328P-PU | ATMEGA88PA-PN |
|---|---|---|---|---|---|
| Package | 28-PDIP (through hole) | 28-PDIP - same footprint | 28-PDIP - same footprint | 28-PDIP - same footprint | 28-PDIP - same footprint |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 16 KB | 16 KB | 16 KB | 32 KB | 8 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 2 KB | 1 KB |
| EEPROM | 512 B | 512 B | 512 B | 1 KB | 512 B |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V (device grade dependent) | 1.8 V to 5.5 V | 2.7 V to 5.5 V |
| picoPower Technology | Yes (PA generation) | Yes | No (predecessor die) | Yes | Yes |
Key Differentiators
- picoPower sleep efficiency vs predecessor (vs ATMEGA168-20PU)
- Double Flash capacity at same price class (vs ATMEGA88PA-PN)
- Lower cost when 16KB suffices (vs ATMEGA328P-PU)
Design Notes
Decouple both VCC (pin 7) and AVCC (pin 20) with 100 nF ceramic capacitors placed within 5 mm of each pin; AVCC must be tied to VCC even if the ADC is unused, per the manufacturer datasheet power section. Add 10 uF bulk capacitance at the board entry point. Estimated: with a 5V rail and 20 MHz full-activity current of roughly 10-15 mA (typical class figure), an LDO such as an AMS1117 dissipates (VIN-5V)*I - keep VIN-to-VOUT delta modest or use a switching pre-regulator above 2 W dissipation.
For through-hole PDIP designs, keep the crystal (or ceramic resonator) within 10 mm of PB6/PB7 (pins 9/10) and route the two crystal traces as a short matched pair away from high-current relay or PWM traces. Place 100 nF across the oscillator supply path. If PC6/RESET (pin 1) is driven by an external programmer header, add a 10 kO pull-up to VCC and a 100 nF series capacitor toward the ICSP connector to prevent level contention during normal operation.
Three frequent mistakes with the ATMEGA168PA-PN: (1) exceeding the safe clock-versus-voltage envelope - do not run 20 MHz at 2.7V; check the frequency-vs-VCC curve in the manufacturer datasheet. (2) Leaving AREF (pin 21) unconnected while enabling the ADC with external reference - always decouple AREF with 100 nF to GND. (3) Using debugWIRE pins for application I/O and then losing debug access - if RESET (PC6) is disabled as a debug pin, recovery requires a high-voltage parallel programmer. Plan ICSP header access before layout freeze.
Thermal management is rarely a concern on this MCU: estimated worst-case dissipation is about 5V x 15 mA = 75 mW, which a 28-PDIP dissipates naturally with junction rise of only a few degrees Celsius. Care is only needed when sourcing heavy loads directly from GPIO - keep per-pin sink/source within datasheet absolute maximums (20 mA per pin class, total device limit per the manufacturer datasheet) and buffer motors or LED arrays with transistors or driver ICs.
Compliance Information
RoHS compliance stated in distributor listing (Veswin: ROHS compliant PDIP-28 package). Not automotive qualified; industrial/consumer target market. Confirm REACH/halogen status via Microchip product compliance documentation.
