ATMEGA48PA-MMNR - 8-Bit AVR 20MHz 4KB MCU | Microchip
MPN: ATMEGA48PA-MMNR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.08 | $2.08 |
| 10 | $1.87 | $18.70 |
| 100 | $1.66 | $166.00 |
| 500 | $1.49 | $745.00 |
| 1,000 | $1.33 | $1,330.00 |
ATMEGA48PA-MMNR Overview
An AVR microcontroller is a Harvard-architecture 8-bit RISC device that executes most instructions in a single clock cycle, sitting in the hierarchy: AVR MCU -> 8-bit microcontroller -> microcontroller -> embedded processor -> semiconductor IC. The ATmega48PA family is Microchip's picoPower line, engineered for low-power embedded control where deterministic real-time response and low quiescent current matter more than raw compute.
Key features include 4 KB Flash with 10,000 write/erase cycles, 256 B EEPROM with 100,000 cycles, 512 B SRAM, three flexible timer/counters with compare modes, a 6-channel 10-bit ADC, a programmable watchdog timer, and an internal calibrated RC oscillator. The picoPower architecture enables sub-1 uA power-down current, making the device suitable for battery-powered nodes.
The ATmega48PA uses a single-cycle RISC core with 32 general-purpose working registers and 131 instructions, most executing in one clock cycle. In-system programming via SPI and a JTAG/debugWIRE interface support field firmware updates and in-circuit debug without removing the device from the board.
Typical applications include battery-powered sensor nodes, consumer appliance control panels, motor control front-ends, and industrial human-machine interfaces. The 28-pin VQFN (4x4 mm) footprint suits space-constrained designs where a full 32-pin TQFP is too large.
When designing with this device, decouple VCC with a 100 nF ceramic capacitor close to each supply pin and keep the AVCC filter network separate from digital VCC to preserve ADC accuracy. The internal RC oscillator removes the need for an external crystal in many cost-sensitive designs.
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 ATMEGA48PA-MMNR 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-MMNR (same form factor and footprint) β differing in Package, ADC, RoHS Status, Flash Memory, Maximum Clock Frequency.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA48PA-MMN
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA48P-20MMU
β Drop-Inβ In Stock
$0.1698 / Unit
View Datasheet βATMEGA48PA-MMNR 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 |
| 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 |
| Working Registers | 32 general purpose |
| Instruction Set | 131 instructions, most single-cycle |
| Timer/Counters | 3 flexible timer/counters with compare modes |
| ADC | 6-channel 10-bit |
| Flash Endurance | 10,000 write/erase cycles |
| EEPROM Endurance | 100,000 write/erase cycles |
| Package | 28-pin VQFN (4x4 mm, 0.45 mm pitch) |
| Mounting Type | Surface Mount |
| Programming Interface | SPI ISP, debugWIRE |
| RoHS Status | Compliant (Green plastic) |
ATMEGA48PA-MMNR Pin Configuration
| Pin 1 | PD3 β Port D, bit 3 / INT1 / OC2B |
| Pin 2 | PD4 β Port D, bit 4 / 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 / XTAL1 / TOSC1 |
| Pin 8 | PB7 β Port B, bit 7 / XTAL2 / TOSC2 |
| Pin 9 | PD5 β Port D, bit 5 / T1 / OC0B |
| Pin 10 | PD6 β Port D, bit 6 / AIN0 / OC0A |
| 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 |
| 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 |
Typical Applications
ATMEGA48PA-MMNR is suitable for 6 applications: Battery-Powered Sensor Nodes, Consumer Appliance Control Panels, Motor Control Front-Ends, Industrial Human-Machine Interfaces, Portable Medical Monitors, Smart Home IoT Endpoints.
Battery-Powered Sensor Nodes
The ATMEGA48PA-MMNR fits battery-powered sensor nodes because its picoPower architecture draws sub-1 uA in power-down mode and operates from 1.8 V to 5.5 V, allowing direct connection to 2xAA or single Li-ion cells. The 6-channel 10-bit ADC samples analog sensors such as thermistors and strain gauges without an external converter, while the 4 KB Flash stores sampling firmware and the 256 B EEPROM retains calibration constants across power cycles. In a typical duty-cycled design the MCU wakes on a timer interrupt, converts a few channels, transmits over UART or SPI, and returns to power-down, averaging microamps. The internal calibrated RC oscillator removes the external crystal, cutting BOM cost and board area in sealed enclosures where a crystal would add a failure point.
Recommended
Consumer Appliance Control Panels
The ATMEGA48PA-MMNR suits consumer appliance control panels because its 23 GPIO lines drive buttons, LEDs, and relays directly while the 20 MHz core handles debouncing and state-machine logic with deterministic single-cycle execution. The 28-pin VQFN (4x4 mm) package fits behind membrane keypads where board space is tight, and the -40 C to +105 C rating covers the internal temperatures of ovens, washing machines, and HVAC controllers. Three timer/counters generate PWM for backlight dimming and buzzer tones without external hardware. The 4 KB Flash is sufficient for menu logic and safety interlocks, and in-system programming via SPI allows firmware updates on the production line after the board is assembled, reducing rework and inventory risk.
Recommended
Motor Control Front-Ends
The ATMEGA48PA-MMNR works as a motor control front-end because its three flexible timer/counters generate complementary PWM outputs for half-bridge gate drivers, and the 10-bit ADC monitors current-sense shunts for overcurrent protection. At 20 MHz the core executes the control loop in single-cycle instructions, giving low jitter for commutation timing in brushed DC and stepper motors. The 23 GPIO lines interface with Hall sensors, limit switches, and direction inputs. The 4 KB Flash holds the commutation table and ramp profiles, while the watchdog timer resets the controller if the loop stalls. The VQFN package's exposed pad improves thermal coupling to the PCB, helping the MCU survive the elevated ambient inside motor housings.
Recommended
Industrial Human-Machine Interfaces
The ATMEGA48PA-MMNR serves industrial HMI designs because its 23 GPIO lines scan key matrices and drive segment or dot-matrix displays, while the 20 MHz core refreshes the display without flicker. The 1.8 V to 5.5 V supply range allows direct interfacing with 5 V legacy industrial logic and 3.3 V modern peripherals on the same board. The 6-channel 10-bit ADC reads potentiometers and membrane keypads with sufficient resolution for menu navigation. The -40 C to +105 C operating range and 28-pin VQFN package suit DIN-rail mounted controllers where vibration and temperature cycling are concerns. In-system programming via SPI enables firmware updates in the field through a service connector without disassembling the enclosure.
Recommended
Portable Medical Monitors
The ATMEGA48PA-MMNR is used in portable medical monitors because its low power-down current extends battery life in wearable glucose meters and pulse oximeters, and the 10-bit ADC digitizes sensor signals with adequate resolution for trend monitoring. The 4 KB Flash stores measurement algorithms and calibration tables, while the 256 B EEPROM retains patient-specific offsets across battery changes. The 1.8 V to 5.5 V range allows operation from a single Li-ion cell without a boost converter, reducing EMI that could corrupt sensitive analog front-ends. The internal RC oscillator avoids crystal-induced jitter in sampling loops. The 28-pin VQFN package keeps the PCB small enough for handheld enclosures, and debugWIRE supports in-circuit debugging during development.
Recommended
Smart Home IoT Endpoints
The ATMEGA48PA-MMNR fits smart home IoT endpoints because it combines a 20 MHz AVR core with 4 KB Flash and 23 GPIO in a 4x4 mm VQFN, leaving board space for a radio module. The device interfaces with sub-GHz or 2.4 GHz transceivers over SPI or UART, handling protocol state machines and sensor polling while the radio sleeps. The 1.8 V to 5.5 V supply matches both coin-cell and 3.3 V rail designs, and sub-1 uA power-down extends coin-cell life to years in door and window sensors. The 6-channel ADC reads reed switches, PIR sensors, and temperature thermistors directly. In-system programming allows OTA-capable gateways to update endpoint firmware through a wired service interface during manufacturing.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA48PA-MMNR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48PA-MMN | ATMEGA48PA-AU | ATMEGA48PA-15MZ | ATMEGA48P-20MMU |
|---|---|---|---|---|---|
| Package | 28-pin VQFN (4x4 mm) | 28-pin QFN - same | 32-pin TQFP - different | 32-pin QFN - different | 28-pin QFN - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 4 KB | 4 KB | 4 KB | 4 KB | 4 KB |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 16 MHz | 20 MHz |
| Supply Voltage Range | 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 Count | 23 | 23 | 23 | 23 | 23 |
| Operating Temperature | -40 C to +105 C | -40 C to +105 C | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C |
| Packaging Format | Tape & Reel | Tray/Tube | Tray | Tray | Tray |
| ADC Channels | 6-channel 10-bit | 6-channel 10-bit | 6-channel 10-bit | 6-channel 10-bit | 6-channel 10-bit |
Key Differentiators
- Tape-and-reel packaging for automated assembly (vs ATMEGA48PA-MMN)
- 28-pin VQFN footprint saves board area (vs ATMEGA48PA-AU)
- Extended 105 C temperature rating (vs ATMEGA48P-20MMU)
- picoPower low-power architecture (vs ATMEGA48PA-15MZ)
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 at the board entry. The AVCC pin requires a separate low-pass filter, typically a 10 uH inductor or ferrite bead in series with a 100 nF capacitor to GND, to isolate the ADC supply from digital switching noise. According to the ATmega48PA datasheet, AVCC must not differ from VCC by more than 0.3 V to keep the ADC within specification.
Connect the exposed thermal pad of the 28-pin VQFN to GND with a grid of vias directly under the pad. The pad is the primary ground return for the die and also conducts heat into the PCB copper. Use at least nine 0.3 mm vias in a 3x3 array to keep ground impedance low and to spread heat. Keep the crystal or resonator traces, if used, shorter than 10 mm and guard them with ground pours to avoid coupling into the ADC inputs.
Do not leave the RESET pin floating; the internal pull-up is weak and noise can trigger spurious resets in electrically noisy environments. Add an external 10 kOhm pull-up to VCC and a 100 nF capacitor to GND if the reset line is routed near motor or relay wiring. Also verify that the ISP programming header does not load the SPI pins during normal operation, since PB3/PB4/PB5 are shared between the SPI peripheral and the in-system programming interface.
Estimated: at 5.5 V and 20 MHz the ATmega48PA core current is approximately 10 mA, giving about 55 mW of dissipation. With a VQFN thermal resistance to ambient of roughly 50 C/W on a typical 2-layer board, the junction rise is about 3 C above ambient, which is negligible. The -40 C to +105 C rating is limited by the package and process, not by self-heating, so no heatsinking is required in normal operation.
Compliance Information
DigiKey and digchip listings describe the package as GREEN plastic, indicating RoHS compliance. The device is not AEC-Q100 qualified; the ATmega48PA-15MZ extended-temperature variant is the closest automotive-adjacent option. REACH, halogen-free, and conflict-minerals status were not stated in the retrieved data.
