ATMEGA48PA-AUR - 8-Bit AVR MCU 4KB Flash 20MHz | Microchip
MPN: ATMEGA48PA-AUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.87 | $2.87 |
| 10 | $2.58 | $25.80 |
| 100 | $2.29 | $229.00 |
| 500 | $2.06 | $1,030.00 |
| 1,000 | $1.83 | $1,830.00 |
| 3,000 | $1.72 | $5,160.00 |
ATMEGA48PA-AUR Overview
An AVR microcontroller is a Harvard-architecture 8-bit MCU that executes most instructions in a single clock cycle using 32 general-purpose working registers. Within the product taxonomy, the ATmega48PA sits under 8-bit microcontrollers, which fall under microcontrollers, which are a subset of integrated circuits. The picoPower design methodology allows the device to retain SRAM contents, keep the real-time counter running, and wake on I2C address match while drawing very low current, which is why AVR parts remain a default choice for battery-powered sensing nodes.
The ATMEGA48PA-AUR integrates 23 general-purpose I/O lines, three flexible timer/counters with compare modes, a 6-channel 10-bit ADC, a programmable watchdog timer with separate on-chip oscillator, an on-chip analog comparator, and a byte-oriented two-wire serial interface compatible with I2C. The internal calibrated oscillator removes the need for an external crystal in many designs, and the programmable brown-out detection protects Flash writes during supply dips.
Architecturally, the device uses the enhanced RISC core with 131 powerful instructions, most executing in a single clock cycle, plus 32 x 8 general-purpose registers that eliminate accumulator bottlenecks. The 4 KB Flash is rated for 10,000 write/erase cycles, the 256 B EEPROM for 100,000 cycles, and both retain data for 20 years at 85 C, giving designers a self-contained non-volatile data store without external memory.
Typical applications include industrial sensor nodes, consumer appliance control panels, battery-powered IoT endpoints, motor control front-ends, and legacy AVR socket upgrades. The 32-TQFP footprint matches the ATmega48PA/88PA/168PA family, so firmware can be ported across memory densities without PCB changes.
A key design consideration is decoupling: place a 100 nF ceramic capacitor directly at each VCC pin and a 10 uF bulk capacitor nearby, because the AVR core draws fast current transients during Flash access. The AVRISP mkII or Atmel-ICE programmer connects through the SPI-based ISP header for in-system programming.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that are not consolidated in the manufacturer datasheet, giving engineers a single reference for selection, cross-reference, and layout decisions.
Drop-in alternatives for ATMEGA48PA-AUR 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 ATMEGA48PA-AUR (same form factor and footprint) β differing in Operating Temperature, RoHS Status, Package, EEPROM, SRAM.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA48PA-AU
β Drop-Inβ In Stock
$1.38 / Unit
View Datasheet βATMEGA48PA-AN
β Drop-Inβ In Stock
$0.83 / Unit
View Datasheet βATMEGA88PA-AU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA168PA-AU
β Drop-Inβ In Stock
$0.98 / Unit
View Datasheet βATMEGA48PA-15MZ
β Drop-Inβ In Stock
$0.68 / Unit
View Datasheet βATMEGA48PA-AUR Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory Size | 4 KB Flash (2K x 16) |
| EEPROM | 256 B |
| SRAM | 512 B |
| Maximum Clock Frequency | 20 MHz |
| Operating Voltage Range | 1.8 V to 5.5 V |
| Supply Voltage (5V operation) | 4.5 V to 5.5 V |
| General Purpose I/O Lines | 23 |
| General Purpose Working Registers | 32 x 8-bit |
| Instruction Set | 131 powerful instructions, most single clock cycle |
| ADC | 6-channel 10-bit |
| Timer/Counters | Three flexible timer/counters with compare modes |
| Serial Interfaces | SPI, USART, 2-wire (I2C compatible) |
| Analog Comparator | One on-chip |
| Watchdog Timer | Programmable with separate on-chip oscillator |
| Internal Oscillator | Calibrated, 8 MHz |
| Flash Endurance | 10,000 write/erase cycles |
| EEPROM Endurance | 100,000 write/erase cycles |
| Data Retention | 20 years at 85 C |
| Package | 32-TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial) |
| RoHS Status | Compliant (Green) |
ATMEGA48PA-AUR Pin Configuration
| Pin 1 | PD3 β Port D, bit 3 / USART1 TXD |
| Pin 2 | PD4 β Port D, bit 4 / Timer0 external counter |
| 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 / XTAL1 / TOSC1 |
| Pin 8 | PB7 β Port B, bit 7 / XTAL2 / TOSC2 |
| Pin 9 | PD5 β Port D, bit 5 / USART1 TXD |
| Pin 10 | PD6 β Port D, bit 6 / USART1 RXD |
| Pin 11 | PD7 β Port D, bit 7 / AIN1 |
| Pin 12 | PB0 β Port B, bit 0 / ICP1 / CLKO |
| Pin 13 | PB1 β Port B, bit 1 / OC1A |
| Pin 14 | PB2 β Port B, bit 2 / SS / OC1B |
| Pin 15 | PB3 β Port B, bit 3 / MOSI / OC2A |
| Pin 16 | PB4 β Port B, bit 4 / MISO |
| Pin 17 | PB5 β Port B, bit 5 / SCK |
| Pin 18 | AVCC β Analog supply voltage |
| 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 / ADC0 |
| Pin 24 | PC1 β Port C, bit 1 / ADC1 |
| Pin 25 | PC2 β Port C, bit 2 / ADC2 |
| Pin 26 | PC3 β Port C, bit 3 / ADC3 |
| Pin 27 | PC4 β Port C, bit 4 / ADC4 / SDA |
| Pin 28 | PC5 β Port C, bit 5 / ADC5 / SCL |
| Pin 29 | PC6 β Port C, bit 6 / RESET |
| Pin 30 | PD0 β Port D, bit 0 / RXD |
| Pin 31 | PD1 β Port D, bit 1 / TXD |
| Pin 32 | PD2 β Port D, bit 2 / INT0 |
Typical Applications
ATMEGA48PA-AUR is suitable for 6 applications: Industrial Sensor Nodes, Battery-Powered IoT Endpoints, Consumer Appliance Control Panels, Motor Control Front-Ends, Legacy AVR Socket Upgrades, Educational and Prototyping Boards.
Industrial Sensor Nodes
The ATMEGA48PA-AUR fits industrial sensor nodes because its 6-channel 10-bit ADC, 23 GPIO lines, and 1.8 V to 5.5 V supply range allow direct interfacing with 4-20 mA loops, thermistors, and bridge sensors without external signal conditioning. Running at 20 MHz, the AVR core executes most instructions in one clock cycle, so a sampling and filtering loop completes in microseconds while the picoPower modes keep average current low. The device is typically placed at the node front-end, sampling sensors through the ADC and transmitting results over its USART or I2C bus to a transceiver. A trade-off is that 4 KB Flash limits complex protocol stacks, so designers often keep the node firmware minimal and push heavy processing to a gateway.
Recommended
Battery-Powered IoT Endpoints
The ATMEGA48PA-AUR is well suited to battery-powered IoT endpoints because its picoPower architecture retains SRAM, keeps the real-time counter running, and wakes on I2C address match at very low current, extending coin-cell life. The internal calibrated 8 MHz oscillator removes the external crystal, reducing BOM cost and board area in compact sensor tags. In a typical design the MCU sleeps between measurements, wakes on a timer or pin-change interrupt, reads a sensor over I2C, and transmits over a sub-GHz or BLE companion radio. The main trade-off is that 512 B SRAM constrains buffer size, so payloads should be kept small or streamed rather than queued.
Recommended
Consumer Appliance Control Panels
The ATMEGA48PA-AUR suits consumer appliance control panels because 23 GPIO lines drive buttons, LEDs, and relays directly, while the three timer/counters generate PWM for backlight dimming and buzzer tones. The 4 KB Flash holds the panel state machine and key-scan logic comfortably, and the 5 V tolerant I/O simplifies interfacing with legacy display drivers. In a typical design the MCU scans a keypad matrix, updates an LED or LCD segment driver, and controls a triac or relay through a driver stage. The trade-off is that the industrial temperature rating of -40 C to +85 C is adequate for appliances but not for under-hood automotive use.
Recommended
Motor Control Front-Ends
The ATMEGA48PA-AUR works as a motor control front-end because its three flexible timer/counters with compare modes generate complementary PWM for half-bridge gate drivers, and the on-chip analog comparator enables back-EMF zero-crossing detection for sensorless BLDC commutation. At 20 MHz the control loop updates fast enough for low-inductance motors, and the 10-bit ADC samples current-sense shunts for overcurrent protection. The MCU typically sits between the gate driver and the host, handling commutation timing and fault shutdown. The trade-off is that 4 KB Flash limits advanced field-oriented control, so it is best for trapezoidal or simple PWM control rather than complex FOC algorithms.
Recommended
Legacy AVR Socket Upgrades
The ATMEGA48PA-AUR is a natural upgrade for legacy ATmega48 and ATmega48A sockets because it shares the 32-TQFP footprint and pinout, so existing PCBs accept the part without layout changes. The picoPower process reduces active and sleep current versus older AVR generations, and the calibrated internal oscillator improves timing accuracy without external components. In a typical migration the designer updates the device signature in the programmer, rebuilds firmware for the ATmega48PA register map, and verifies brown-out and watchdog settings. The trade-off is that some legacy code relies on removed or relocated registers, so a full regression test is required after the swap.
Recommended
Educational and Prototyping Boards
The ATMEGA48PA-AUR is popular on educational and prototyping boards because the AVR instruction set is well documented, the ISP header allows in-system programming with low-cost tools, and the 32-TQFP package is easy to route on two-layer boards. Students can blink LEDs, read the 10-bit ADC, and drive I2C displays using the same toolchain as the Arduino ecosystem. In a typical board the MCU connects to an ISP header, a reset button, and breakout headers for the 23 GPIO lines. The trade-off is that 4 KB Flash is tight for large Arduino libraries, so teaching code should be kept modular and lean.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA48PA-AUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48PA-AU | ATMEGA48PA-AN | ATMEGA88PA-AU | ATMEGA168PA-AU |
|---|---|---|---|---|---|
| Package | 32-TQFP (7x7) | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same | 32-TQFP (7x7) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 4 KB | 4 KB | 4 KB | 8 KB | 16 KB |
| SRAM | 512 B | 512 B | 512 B | 1 KB | 1 KB |
| EEPROM | 256 B | 256 B | 256 B | 512 B | 512 B |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating 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 | 1.8 V to 5.5 V |
| GPIO Lines | 23 | 23 | 23 | 23 | 23 |
| Packaging | Tape & Reel | Tray / Cut Tape | Tray | Tray / Cut Tape | Tray / Cut Tape |
| Automotive Grade | No (industrial -40 C to +85 C) | No | No | No | Yes (automotive variant) |
Key Differentiators
- Tape-and-reel packaging for automated SMT assembly (vs ATMEGA48PA-AU)
- Pin-compatible memory upgrade path within the same footprint (vs ATMEGA88PA-AU)
- picoPower low-current modes with internal calibrated oscillator (vs ATMEGA168PA-AU)
- Lower unit cost for memory-constrained designs (vs ATMEGA168PA-AU)
Design Notes
Decouple every VCC pin with a 100 nF ceramic capacitor placed within 2 mm of the pin, and add a 10 uF bulk capacitor near the package. The AVR core draws fast current transients during Flash access, so a single shared decoupling capacitor is insufficient. Connect AVCC through a separate 100 nF capacitor and a ferrite bead or 10 ohm resistor from VCC to isolate ADC noise. Keep AREF decoupled with 100 nF to GND when using the internal reference.
Route the 32-TQFP land pattern with 0.45 mm pitch and keep the ISP header (MOSI, MISO, SCK, RESET, VCC, GND) on a short, direct path to the MCU pins. Place the crystal, if used, within 10 mm of XTAL1/XTAL2 with symmetrical ground guard traces. Keep the analog input traces to ADC0-ADC7 away from the SPI and USART lines to preserve 10-bit ADC accuracy.
Do not leave the RESET pin floating; add a 10 kohm pull-up to VCC and a 100 nF capacitor to GND to prevent spurious resets. When migrating from ATmega48 or ATmega48A, update the device signature in the programmer and re-verify the brown-out detection level, because the ATmega48PA uses a different signature and BOD threshold table. Estimated: at 5 V and 20 MHz the core draws roughly 10-12 mA, so size the regulator for at least 25 mA to cover I/O and peripheral load.
Compliance Information
Distributor listings describe ATMEGA48PA-AUR as a Green, lead-free 32-TQFP package and RoHS compliant. REACH, halogen-free, and conflict-minerals status were not stated in the retrieved data and are marked unknown. The standard -AUR is an industrial-temperature part; automotive qualification requires the separate ATmega48PA automotive variant.
