ATMEGA168PA-MUR - 8-Bit AVR MCU 16KB Flash 20MHz VQFN-32 | Microchip
MPN: ATMEGA168PA-MUR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.72 | $2.72 |
| 10 | $2.45 | $24.50 |
| 100 | $2.15 | $215.00 |
| 500 | $1.92 | $960.00 |
| 1,000 | $1.75 | $1,750.00 |
ATMEGA168PA-MUR Overview
An 8-bit AVR microcontroller is a Harvard-architecture RISC processor that executes most of its 133 instructions in a single clock cycle. Within the power-management hierarchy, the ATmega family sits in the embedded microcontroller (MCU) class, integrating CPU, program memory, data memory, timers, and communication peripherals on a single die, making it a complete system-on-chip for cost-sensitive embedded control.
Key features include the picoPower technology for sub-uA power modes, 16 KB of self-programmable Flash with read-while-write support, a 10-bit ADC with up to 8 channels, and a rich peripheral set: one 8-bit and one 16-bit timer with compare modes, a 6-channel PWM engine, a serial USART, a byte-oriented Two-Wire (I2C-compatible) interface, and an SPI port. The advanced RISC core uses 32 general-purpose working registers fully connected to the ALU, achieving up to 20 MIPS throughput at 20 MHz.
Technically, the ATmega168PA is the picoPower refresh of the ATmega168A die, fabricated to reduce active and sleep-mode current. It operates from 2.7 V to 5.5 V and offers power-saving modes including Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby, with on-chip brown-out detection, power-on reset, and an internal calibrated RC oscillator.
Typical applications include consumer appliances, industrial sensing nodes, battery-powered instruments, HVAC controls, and hobby/Arduino-class boards, where the combination of 5 V tolerance, low sleep current, and in-system programmability reduces total system cost.
For design, remember the VQFN pad-frame requires a grounded center paddle for thermal and signal return integrity; place 100 nF decoupling capacitors at both VCC/AVCC pairs.
This page synthesizes distributor pricing, same-footprint drop-in alternatives, and pinout data not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA168PA-MUR — 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-MUR (same form factor and footprint) — differing in Package, Operating Temperature, Communication Interfaces, Timers, ADC Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA168PA-MU
✅ Drop-In✓ In Stock
$1.72 / Unit
View Datasheet →ATMEGA168A-MUR
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →ATMEGA168P-20MUR
✅ Drop-In✓ In Stock
$1.58 / Unit
View Datasheet →ATMEGA328P-MU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.28 / Unit
View Datasheet →ATMEGA88PA-MU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA48PA-MU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA168PA-MUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 16 KB (8K x 16) |
| EEPROM | 512 B |
| SRAM | 1 KB |
| Maximum Clock Frequency | 20 MHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| GPIO Count | 23 programmable I/O lines |
| ADC Resolution | 10-bit |
| ADC Channels | 8 channels |
| Timers | 1 x 8-bit, 1 x 16-bit |
| Communication Interfaces | USART, SPI, TWI (I2C-compatible) |
| PWM Channels | 6 |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 32-VQFN (5x5 mm), MLF-32 |
| Mounting Type | Surface Mount |
| Low Power Technology | picoPower |
| RoHS Status | Compliant (Green) |
ATMEGA168PA-MUR Pin Configuration
| Pin 1 | PD3 — Port D bit 3 (GPIO / OC2B PWM) |
| Pin 2 | PD4 — Port D bit 4 (GPIO / 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 / XTAL1 / TOSC1 (crystal input) |
| Pin 8 | PB7 — Port B bit 7 / XTAL2 / TOSC2 (crystal output) |
| Pin 9 | PD5 — Port D bit 5 (GPIO / OC0B / T1) |
| Pin 10 | PD6 — Port D bit 6 (GPIO / OC0A / AIN0) |
| Pin 11 | PD7 — Port D bit 7 (GPIO / AIN1) |
| Pin 12 | PB0 — Port B bit 0 (GPIO / XCK0 / T0 / ICP1) |
| Pin 13 | PB1 — Port B bit 1 (GPIO / OC1A) |
| Pin 14 | PB2 — Port B bit 2 (GPIO / SS / OC1B) |
| Pin 15 | PB3 — Port B bit 3 (GPIO / MOSI / OC2A) |
| Pin 16 | PB4 — Port B bit 4 (GPIO / MISO) |
| Pin 17 | PB5 — Port B bit 5 (GPIO / SCK) |
| Pin 18 | AVCC — Analog supply voltage for ADC |
| Pin 19 | ADC6 — Analog input channel 6 |
| Pin 20 | AREF — ADC analog reference |
| Pin 21 | GND — Ground |
| Pin 22 | ADC7 — Analog input channel 7 |
| Pin 23 | PC0 — Port C bit 0 / ADC0 |
| Pin 24 | PC1 — Port C bit 1 / ADC1 |
| Pin 25 | PC2 — Port C bit 2 / ADC2 |
| Pin 26 | PC3 — Port C bit 3 / ADC3 |
| Pin 27 | PC4 — Port C bit 4 / ADC4 / SDA (TWI) |
| Pin 28 | PC5 — Port C bit 5 / ADC5 / SCL (TWI) |
| Pin 29 | PC6 — Port C bit 6 / RESET (active-low reset) |
| Pin 30 | PD0 — Port D bit 0 / RXD (USART receive) |
| Pin 31 | PD1 — Port D bit 1 / TXD (USART transmit) |
| Pin 32 | PD2 — Port D bit 2 / INT0 (external interrupt) |
Typical Applications
ATMEGA168PA-MUR is suitable for 6 applications: Battery-Powered Sensor Nodes, Industrial Control and Automation, Consumer Appliances, HVAC and Climate Control, Embedded Hobby and Maker Boards, Medical and Diagnostic Instruments.
Battery-Powered Sensor Nodes
The ATMEGA168PA-MUR fits battery nodes because picoPower Power-down mode reduces sleep current to the low-microampere/sub-microampere class while the watchdog or asynchronous Timer/Counter can wake the CPU periodically. The 10-bit ADC with 8 channels digitizes analog sensors directly without an external converter, and the internal calibrated RC oscillator removes the crystal from the bill of materials in non-timing-critical designs. Powered from 2.7 V to 5.5 V, it runs from two AA cells or a 3 V coin cell through an LDO. A typical topology sleeps in Power-down, wakes on timer or pin-change interrupt, samples the ADC, and transmits via USART or SPI radio; the trade-off is avoiding 20 MHz operation at low battery voltage per the voltage-frequency derating curve.
Recommended
Industrial Control and Automation
In industrial controllers the ATMEGA168PA-MUR offers 5 V-tolerant I/O, brown-out detection, and a -40C to +85C industrial temperature rating, which simplify interfacing with relays, optocouplers, and 24 V-scaled signal conditioning. Its six PWM channels drive actuators, heater elements, or LED dimming directly, while the USART, SPI, and TWI interfaces connect to HMI panels, EEPROMs, and Modbus-over-RS485 transceivers. The 16 KB self-programmable Flash supports field firmware updates through a bootloader, reducing maintenance cost. Placed on a 5 V rail with 100 nF decoupling at both VCC pins and a grounded MLF paddle, it delivers up to 20 MIPS of deterministic RISC execution; designers should budget ISR latency carefully in fast closed-loop control and use the 16-bit Timer/Counter for precise PWM periods.
Recommended
Consumer Appliances
Home appliances need inexpensive, robust control: the ATMEGA168PA-MUR supplies a full MCU with ADC, PWM, USART, and TWI in a 5x5 mm VQFN, keeping board area small in dishwasher, coffee machine, and climate-control boards. Its 2.7 V to 5.5 V range tolerates unregulated supply sag, the on-chip power-on reset and brown-out detector protect against brownout-induced firmware corruption, and 512 B EEPROM retains user settings through power cycles. Push-button interfaces use pin-change interrupts, and the 8-bit Timer/Counter handles buzzer or display multiplexing while the CPU sleeps in Idle mode to cut consumption. With unit pricing around the two-to-three dollar level, the total programmed-MCU cost stays low; the main consideration is ESD hardening of externally accessible I/O lines with TVS diodes.
Recommended
HVAC and Climate Control
Thermostats and HVAC controllers benefit from the ATMEGA168PA-MUR asynchronous Timer/Counter, which keeps a real-time clock running in Power-save mode at microamp-level current between display updates. The 10-bit ADC reads NTC thermistors, humidity sensors, and supply-voltage dividers across up to 8 channels, while TWI connects external RTC or display controllers and USART supports UART-based diagnostics ports. The 23 GPIO lines drive relays, dampers, and multi-segment LCD or LED displays through driver transistors. Operating from a transformer-derived 5 V rail with brown-out detection at approximately 2.7 V, the design safely resumes operation after mains dips. Firmware should average ADC samples to reject 50/60 Hz mains coupling and use the internal 1.1 V reference for accurate thermistor conversion across the industrial temperature range.
Recommended
Embedded Hobby and Maker Boards
The ATmega168PA is a direct pin-compatible member of the Arduino Uno-class family, and the ATMEGA168PA-MUR in VQFN-32 suits compact maker hardware where the DIP-28 ATmega328P is too large. It accepts the standard Arduino bootloader via UART or ISP programming with AVR ISP mkII, PICkit 4, or Atmel-ICE, and the same SPI/ISP header layout used across ATmega48/88/168/328 boards works unchanged. Six PWM outputs, a hardware USART, and 23 GPIO lines cover servo, LED, and sensor projects, while 16 KB Flash hosts moderately sized sketches; designs that outgrow 16 KB simply reflow the pin-identical ATMEGA328P-MU onto the same PCB. Keep reset, MOSI, MISO, and SCK routed to a 2x3 ISP header for in-field reprogramming.
Recommended
Medical and Diagnostic Instruments
Portable medical devices such as glucose meters, blood-pressure monitors, and handheld diagnostic tools use the ATMEGA168PA-MUR for its combination of low sleep current, 10-bit ADC, and deterministic single-cycle RISC execution for signal timing. Battery operation from 2.7 V supports 3 V lithium cells, and picoPower modes extend shelf life between charging cycles; ADC Noise Reduction mode suppresses digital clock noise during measurement conversions, improving effective resolution on low-level sensor inputs. TWI connects calibration EEPROMs and OLED display controllers, while USART provides service interfaces. Because this device is not AEC-Q100 or medical-grade qualified as a component, safety-critical paths should add external supervision; the MCU handles measurement, UI, and communications within a system-level IEC 60601-compliant architecture designed by the instrument manufacturer.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168PA-MUR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168PA-MU | ATMEGA168A-MUR | ATMEGA328P-MU | ATMEGA88PA-MU | ATMEGA48PA-MU |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 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 |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Low Power Technology | picoPower (PA) | picoPower (PA) | Standard (non-picoPower) | picoPower-class | picoPower (PA) | picoPower (PA) |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
Key Differentiators
- picoPower sleep currents vs standard die (vs ATMEGA168A-MUR)
- Memory upgrade path in identical footprint (vs ATMEGA328P-MU)
- Cost-down option for simple firmware (vs ATMEGA48PA-MU)
Design Notes
The 32-pad VQFN (MLF) exposed die paddle on the ATMEGA168PA-MUR is not internally bonded to GND on all assembly variants - verify the datasheet paddle note, but best practice is to connect the paddle to a solid ground plane via a 3x3 via array under the part. This provides mechanical anchoring for reflow, thermal spreading, and a low-inductance return path. Use NSMD pads with approximately 0.3 mm aperture and 0.5 mm pitch per the package drawing, and design the stencil with roughly 50-70% paddle coverage to avoid solder voiding.
Decouple both VCC pins (4 and 6) and AVCC (pin 18) each with a 100 nF ceramic capacitor placed within 2 mm of the pin, plus one bulk 4.7-10 uF per supply rail. Tie AVCC to VCC through a low-pass filter (10 nH ferrite plus 100 nF) when ADC accuracy matters, and never leave AVCC unconnected even if the ADC is unused - the datasheet requires AVCC within 0.3 V of VCC. AREF should have a 100 nF capacitor to ground; only drive it externally when a precision reference is genuinely needed.
Three frequent ATmega168PA pitfalls: (1) PC6/RESET must not be left floating or pulled high weakly below the minimum reset threshold - use 10 kOhm pull-up plus a 100 nF cap from RESET to ground for robust power-on reset behavior with ISP headers. (2) ISP pins (PB3/MOSI, PB4/MISO, PB5/SCK) should have series resistors (e.g. 330 Ohm) if those nets drive external loads, so a programmer can override them. (3) At 3.3 V the safe maximum clock is roughly 13.3 MHz per the frequency-voltage curve - running 20 MHz crystals at low VCC violates the datasheet derating and causes marginal operation.
Estimated: at 5 V and 20 MHz driving nominal GPIO load, the ATMEGA168PA-MUR typically dissipates on the order of tens of milliwatts - with a theta_JA in the 40-50 C/W class for a 5x5 mm VQFN on a standard 4-layer board, the junction temperature rise above ambient is only a few degrees C, so no heatsinking is required. Thermal design only becomes relevant if many I/O pins source/sink near the 40 mA absolute-maximum pin current continuously; keep per-pin DC current within the datasheet 20 mA recommended rating.
Compliance Information
Distributor data (FindIC, Jotrin) lists the ATMEGA168PA-MUR as Green/RoHS with lead-free matte-tin finish. No AEC-Q100 qualification is claimed for the ATmega168PA family. REACH and conflict-minerals status should be confirmed via the Microchip product compliance portal.
