ATMEGA168PA-ANR - 16KB AVR 8-Bit MCU 20MHz | Microchip
MPN: ATMEGA168PA-ANR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.35 | $2.35 |
| 10 | $2.12 | $21.20 |
| 100 | $1.89 | $189.00 |
| 500 | $1.72 | $860.00 |
| 1,000 | $1.58 | $1,580.00 |
| 3,000 | $1.44 | $4,320.00 |
ATMEGA168PA-ANR Overview
An AVR microcontroller is a Harvard-architecture 8-bit RISC device that executes most instructions in a single clock cycle, sitting within the hierarchy of microcontroller -> embedded processor -> integrated circuit -> semiconductor. The ATmega family is the classic general-purpose AVR line, and the PA suffix denotes the picoPower generation with reduced active and standby current for battery-powered designs.
Key differentiators include 16 KB flash with read-while-write self-programming, 512 bytes of true EEPROM for non-volatile parameter storage, and a wide 1.8 V to 5.5 V supply that allows direct operation from single-cell Li-Ion or 3xAA battery stacks without a regulator. The 32-TQFP (7x7 mm) body keeps the footprint compact while exposing all 23 I/O lines.
The device integrates three flexible timer/counters with compare modes, a programmable USART, a byte-oriented Two-Wire serial interface (I2C), an SPI port, internal and external interrupts, a 6-channel PWM, a programmable watchdog timer with separate oscillator, and brown-out detection. The 10-bit ADC with 8 multiplexed channels supports temperature sensing and analog front ends.
Typical applications include battery-powered sensor nodes, consumer appliance control panels, motor control front ends, LED lighting controllers, and legacy Arduino-compatible designs. The 1.8 V minimum supply and sub-microamp power-down mode make it well suited to energy-harvesting and coin-cell products.
A key design consideration is that the TQFP-32 land pattern is shared across the ATmega48PA/88PA/168PA family, so firmware can be scaled up or down without PCB changes. Decouple VCC and AVCC with 100 nF ceramic capacitors placed within a few millimeters of the pins, and keep the 32 kHz crystal traces short if using an external RTC crystal.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single reference for selection, replacement, and layout decisions.
Drop-in alternatives for ATMEGA168PA-ANR β 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-ANR (same form factor and footprint) β differing in Throughput, Timer/Counters, Working Registers, Supply Voltage Range, EEPROM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA168PA-AU
β Drop-Inβ In Stock
$0.98 / Unit
View Datasheet βATMEGA168P-20AN
β Drop-Inβ In Stock
$1.72 / Unit
View Datasheet βATMEGA168P-20ANR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA88PA-ANR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA48PA-ANR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA168A-ANR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA168PA-ANR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory Size | 16 KB (8K x 16) Flash |
| Flash Endurance | 10,000 write/erase cycles (typical) |
| SRAM | 1 KB |
| EEPROM | 512 bytes |
| Maximum CPU Speed | 20 MHz |
| Throughput | Up to 20 MIPS at 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Operating Temperature Range | -40 C to +105 C |
| General Purpose I/O Lines | 23 |
| General Purpose Working Registers | 32 |
| ADC | 8-channel 10-bit successive approximation |
| Timer/Counters | 3 flexible timer/counters with compare modes |
| Serial Interfaces | USART, SPI, Two-Wire (I2C) |
| PWM Channels | 6 |
| On-Chip Debug | debugWIRE |
| Brown-Out Detection | Yes, programmable |
| Watchdog Timer | Yes, with separate on-chip oscillator |
| Package | 32-TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATMEGA168PA-ANR Pin Configuration
| Pin 1 | PD3 β Port D bit 3, also INT1, OC2B |
| Pin 2 | PD4 β Port D bit 4, also T0, XCK |
| Pin 3 | GND β Ground |
| Pin 4 | VCC β Digital supply voltage |
| Pin 5 | GND β Ground |
| Pin 6 | VCC β Digital supply voltage |
| Pin 7 | PB6 β Port B bit 6, also XTAL1/TOSC1 |
| Pin 8 | PB7 β Port B bit 7, also XTAL2/TOSC2 |
| Pin 9 | PD5 β Port D bit 5, also T1, OC0B |
| Pin 10 | PD6 β Port D bit 6, also AIN0, OC0A |
| Pin 11 | PD7 β Port D bit 7, also AIN1 |
| Pin 12 | PB0 β Port B bit 0, also ICP1, CLKO |
| Pin 13 | PB1 β Port B bit 1, also OC1A |
| Pin 14 | PB2 β Port B bit 2, also SS, OC1B |
| Pin 15 | PB3 β Port B bit 3, also MOSI, OC2A |
| Pin 16 | PB4 β Port B bit 4, also MISO |
| Pin 17 | PB5 β Port B bit 5, also SCK |
| Pin 18 | AVCC β Analog supply voltage for ADC |
| Pin 19 | ADC6 β Analog input channel 6 |
| Pin 20 | AREF β Analog reference voltage |
| Pin 21 | GND β Ground |
| Pin 22 | ADC7 β Analog input channel 7 |
| Pin 23 | PC0 β Port C bit 0, also ADC0 |
| Pin 24 | PC1 β Port C bit 1, also ADC1 |
| Pin 25 | PC2 β Port C bit 2, also ADC2 |
| Pin 26 | PC3 β Port C bit 3, also ADC3 |
| Pin 27 | PC4 β Port C bit 4, also ADC4, SDA |
| Pin 28 | PC5 β Port C bit 5, also ADC5, SCL |
| Pin 29 | PC6 β Port C bit 6, also RESET |
| Pin 30 | PD0 β Port D bit 0, also RXD |
| Pin 31 | PD1 β Port D bit 1, also TXD |
| Pin 32 | PD2 β Port D bit 2, also INT0 |
Typical Applications
ATMEGA168PA-ANR is suitable for 6 applications: Battery-Powered Sensor Nodes, Consumer Appliance Control Panels, Motor Control Front Ends, LED Lighting Controllers, Arduino-Compatible Prototyping, Industrial Data Loggers.
Battery-Powered Sensor Nodes
The ATMEGA168PA-ANR fits battery-powered sensor nodes because its picoPower design operates from 1.8 V to 5.5 V and draws well under 1 uA in power-down mode, allowing multi-year operation from a coin cell. The 8-channel 10-bit ADC digitizes thermistors, pressure bridges, and light sensors directly without external signal conditioning, while the 512-byte EEPROM stores calibration coefficients across power cycles. In a typical node, the MCU wakes on a watchdog or pin-change interrupt, samples the ADC, and transmits over USART or SPI to a sub-GHz radio. The trade-off versus a 32-bit Cortex-M0+ is lower clock speed and no hardware floating point, but the 1.8 V minimum supply and mature sleep modes give lower standby current in simple duty-cycled designs.
Recommended
Consumer Appliance Control Panels
The ATMEGA168PA-ANR suits appliance control panels because its 23 general-purpose I/O lines and 6 PWM channels drive buttons, LEDs, relays, and triac gates without port expanders, and the -40 C to +105 C rating covers the internal temperatures of ovens, washing machines, and HVAC units. The 16 KB flash holds user-interface state machines and safety interlocks, while the programmable brown-out detector prevents corrupted writes during mains sags. In a typical design the MCU scans a capacitive or membrane keypad, updates a multiplexed LED display, and controls a motor or heater through an opto-isolated triac. The trade-off versus a dedicated appliance ASIC is higher BOM cost, but the AVR's in-system programmability allows firmware updates in the field.
Recommended
Motor Control Front Ends
The ATMEGA168PA-ANR works as a motor control front end because its three flexible timer/counters generate complementary PWM with dead-time control, and the 10-bit ADC samples current-shunt and back-EMF signals for closed-loop commutation. At 20 MHz the core executes 20 MIPS, enough for six-step BLDC commutation and simple PI current loops at multi-kHz rates. The 16 KB flash stores commutation tables and fault-handling code, and the analog comparator enables cycle-by-cycle overcurrent shutdown. In a typical design the MCU drives a gate driver such as the DRV8301 while monitoring phase currents through the ADC. The trade-off versus a dedicated motor-control MCU is the absence of hardware PWM dead-time insertion, so firmware must enforce shoot-through protection.
Recommended
LED Lighting Controllers
The ATMEGA168PA-ANR is used in LED lighting controllers because its 6 PWM channels dim constant-current LED drivers, and the 10-bit ADC reads ambient-light sensors for automatic brightness control. The 1.8 V to 5.5 V supply allows direct operation from a 3.3 V or 5 V rail derived from the LED driver's auxiliary output, eliminating a separate regulator. The 16 KB flash holds dimming curves, DALI or DMX-512 protocol stacks, and thermal derating tables, while the USART supports wired control buses. In a typical design the MCU generates PWM for a buck or boost LED driver and monitors an NTC for over-temperature foldback. The trade-off versus a dedicated LED controller is higher software overhead, but the AVR offers full protocol flexibility.
Recommended
Arduino-Compatible Prototyping
The ATMEGA168PA-ANR is a natural fit for Arduino-compatible prototyping because it is the same AVR core used on early Arduino boards, so the bootloader, toolchain, and thousands of libraries apply directly. The 32-TQFP (7x7 mm) package exposes all 23 I/O lines, and the 16 KB flash accommodates the Arduino bootloader plus a moderate sketch. The debugWIRE interface allows on-chip debugging without a JTAG header, and the internal 8 MHz RC oscillator lets the board run without an external crystal. In a typical design the MCU is programmed over USART through a USB-serial bridge and drives shields through the standard header pinout. The trade-off versus a modern 32-bit board is limited memory and no USB peripheral.
Recommended
Industrial Data Loggers
The ATMEGA168PA-ANR serves industrial data loggers because the 512-byte EEPROM retains calibration and configuration without external memory, and the -40 C to +105 C temperature rating covers factory-floor environments. The 8-channel 10-bit ADC samples 4-20 mA loops through sense resistors, while the USART and SPI interfaces connect to RS-485 transceivers and SD-card controllers. The 16 KB flash stores timestamping logic and Modbus RTU stacks, and the watchdog timer with independent oscillator recovers from EMI-induced lockups. In a typical design the MCU samples sensors at fixed intervals, timestamps readings, and writes them to removable storage. The trade-off versus an ARM Cortex-M logger is lower sample throughput, but the 5 V-tolerant I/O simplifies interfacing to legacy industrial sensors.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA168PA-ANR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA168PA-AU | ATMEGA168P-20AN | ATMEGA88PA-ANR | ATMEGA48PA-ANR |
|---|---|---|---|---|---|
| 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 |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 16 KB | 16 KB | 16 KB | 8 KB | 4 KB |
| SRAM | 1 KB | 1 KB | 1 KB | 1 KB | 512 B |
| EEPROM | 512 bytes | 512 bytes | 512 bytes | 512 bytes | 256 bytes |
| Maximum Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V | 1.8 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 |
| General Purpose I/O Lines | 23 | 23 | 23 | 23 | 23 |
| ADC Channels / Resolution | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit |
| Operating Temperature Range | -40 C to +105 C | -40 C to +105 C | -40 C to +85 C | -40 C to +105 C | -40 C to +105 C |
| Packaging Format | Tape & Reel | Tray | Tube | Tape & Reel | Tape & Reel |
Key Differentiators
- picoPower low-voltage operation (vs ATMEGA168P-20AN)
- Double the flash of the 8 KB family member (vs ATMEGA88PA-ANR)
- Extended temperature rating (vs ATMEGA168P-20AN)
- Tape-and-reel delivery for automated assembly (vs ATMEGA168PA-AU)
Design Notes
Decouple both VCC pins (pins 4 and 6) and the AVCC pin (pin 18) with 100 nF ceramic capacitors placed within a few millimeters of the package, and add a 10 uF bulk capacitor on the board rail. If the ADC is used, insert a 10 uH inductor or ferrite bead between VCC and AVCC to isolate digital switching noise from the analog supply, as recommended in the Microchip ATmega48PA/88PA/168PA datasheet.
Keep the external crystal or resonator traces between XTAL1 (pin 7) and XTAL2 (pin 8) as short as possible and guard them with ground, since these pins are shared with the TOSC1/TOSC2 32 kHz RTC function. Place the load capacitors symmetrically and connect their ground returns directly to the MCU ground plane. Route the RESET pin (pin 29) away from switching nodes and add a 100 nF capacitor to ground to prevent spurious resets.
Do not exceed the 20 MHz maximum clock at low supply voltages: the ATmega168PA speed grades require at least 4.5 V for 20 MHz, 2.7 V for 10 MHz, and 1.8 V for 4 MHz. Running 20 MHz at 1.8 V causes unreliable operation. Also ensure the debugWIRE enable fuse is not left programmed in production, as it disables the RESET pin function and prevents normal reset operation.
Estimated: the ATmega168PA-ANR dissipates roughly 15-25 mW at 5 V and 8 MHz in active mode, based on a typical supply current of 3-5 mA. With a 32-TQFP theta_JA near 60 C/W, the junction rise above ambient is under 2 C, so no thermal relief is required. Verify against the datasheet supply-current curves for your actual clock and voltage before finalizing a high-temperature design.
Compliance Information
RoHS compliance and lead-free status are stated on the Microchip ATmega168PA product page and distributor listings. AEC-Q100 automotive qualification is not claimed for this part; automotive-grade AVR variants should be selected for such designs. REACH, halogen-free, and conflict-minerals status were not present in the retrieved data.
