ATMEGA48PA-PN - 8-Bit AVR MCU 20MHz 4KB Flash 28-PDIP | Microchip
MPN: ATMEGA48PA-PN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.25 | $1.25 |
| 10 | $1.12 | $11.20 |
| 100 | $0.98 | $98.00 |
| 500 | $0.86 | $430.00 |
| 1,000 | $0.75 | $750.00 |
ATMEGA48PA-PN Overview
An 8-bit microcontroller integrates a processor core, memory, and peripherals on a single chip, sitting within the broader hierarchy of MCU -> embedded processor -> semiconductor device. The ATmega48PA belongs to the AVR ATmega family, built on the Advanced RISC architecture with 131 powerful instructions, most executing in a single clock cycle, giving it a throughput class rarely matched in its price tier.
Key features include a 2-stage pipeline Harvard architecture, 8-bit and 16-bit timers, a 10-bit ADC, USI and USART serial interfaces, and picoPower technology for ultra-low sleep currents. The PA suffix denotes the picoPower revision, making it well suited for battery-powered designs that spend most of their life in sleep modes. Supply operation spans the 2.5V to 5.5V ranges documented for this part, and the operating temperature extends to 105C per the Mouser listing.
The AVR core achieves 20 MIPS at 20 MHz while consuming minimal dynamic power, and its In-System Programmable Flash allows firmware updates on the assembled PCB through the SPI-based ICSP interface. The self-programmable flash also enables boot-loader based updates without a dedicated programmer.
Typical applications include appliance control boards, battery-powered sensors, hobby and educational platforms, industrial subsystem controllers, and legacy AVR designs where the through-hole 28-PDIP package simplifies prototyping and hand assembly.
A key design consideration is clocking: the internal 8 MHz RC oscillator avoids external components, but precision UART timing benefits from an external crystal; note that with the PB-family migration, Microchip documents pin 3 and pin 6 cautions when using ATmega48PB as a drop-in.
This page synthesizes distributor listings, cross-reference migration guidance, pinout data, and drop-in alternatives not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA48PA-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 ATMEGA48PA-PN (same form factor and footprint) — differing in EEPROM, SRAM, Operating Temperature, Supply Voltage Range, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA48PA-PU
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View Datasheet →ATMEGA48-20PI
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View Datasheet →ATMEGA48PA-PN Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Flash Memory | 4KB (2K x 16) In-System Programmable |
| EEPROM | 256 B |
| SRAM | 512 B |
| Maximum Clock Frequency | 20 MHz |
| Maximum MIPS | 20 MIPS at 20 MHz |
| I/O Ports | 23 programmable I/O lines |
| Package | 28-PDIP |
| Mounting Type | Through-Hole |
| Operating Temperature | -40C to +105C |
| Timers | 8-bit and 16-bit timers |
| Serial Interfaces | USART, USI, SPI (ICSP) |
| Instruction Set | 131 instructions, most single-cycle |
| Low Power Technology | picoPower (PA revision) |
| In-Circuit Programming | ICSP via SPI + reset line |
| RoHS Status | Lead-free (N suffix) |
ATMEGA48PA-PN Pin Configuration
| Pin 1 | PC6 (RESET) — Reset input / Port C bit 6 |
| Pin 2 | PD0 (RXD) — USART receive / Port D bit 0 |
| Pin 3 | PD1 (TXD) — USART transmit / Port D bit 1 |
| Pin 4 | PD2 (INT0) — External interrupt 0 / Port D bit 2 |
| Pin 5 | PD3 (INT1) — External interrupt 1 / Port D bit 3 |
| Pin 6 | PD4 (T0/XCK) — Timer 0 input / USART clock / Port D bit 4 |
| Pin 7 | VCC — Digital supply voltage |
| Pin 8 | GND — Ground |
| Pin 9 | PB6 (XTAL1/TOSC1) — Crystal oscillator input / Port B bit 6 |
| Pin 10 | PB7 (XTAL2/TOSC2) — Crystal oscillator output / Port B bit 7 |
| Pin 11 | PD5 (T1/OC0B) — Timer 1 input / Timer 0 output compare B / Port D bit 5 |
| Pin 12 | PD6 (AIN0/OC0A) — Analog comparator positive input / Timer 0 output compare A / Port D bit 6 |
| Pin 13 | PD7 (AIN1/PCINT23) — Analog comparator negative input / Port D bit 7 |
| Pin 14 | PB0 (ICP1/CLKO/PCINT0) — Timer 1 input capture / clock output / Port B bit 0 |
| Pin 15 | PB1 (OC1A/PCINT1) — Timer 1 output compare A / Port B bit 1 |
| Pin 16 | PB2 (SS/OC1B/PCINT2) — SPI slave select / Timer 1 output compare B / Port B bit 2 |
| Pin 17 | PB3 (MOSI/OC2A/PCINT3) — SPI master output / Timer 2 output compare A / Port B bit 3 |
| Pin 18 | PB4 (MISO/PCINT4) — SPI master input / Port B bit 4 |
| Pin 19 | PB5 (SCK/PCINT5) — SPI clock / Port B bit 5 |
| Pin 20 | AVCC — ADC supply voltage |
| Pin 21 | AREF — ADC analog reference |
| Pin 22 | GND — Ground |
| Pin 23 | PC0 (ADC0/PCINT8) — ADC channel 0 / Port C bit 0 |
| Pin 24 | PC1 (ADC1/PCINT9) — ADC channel 1 / Port C bit 1 |
| Pin 25 | PC2 (ADC2/PCINT10) — ADC channel 2 / Port C bit 2 |
| Pin 26 | PC3 (ADC3/PCINT11) — ADC channel 3 / Port C bit 3 |
| Pin 27 | PC4 (ADC4/SDA/PCINT12) — ADC channel 4 / TWI SDA / Port C bit 4 |
| Pin 28 | PC5 (ADC5/SCL/PCINT13) — ADC channel 5 / TWI SCL / Port C bit 5 |
Typical Applications
ATMEGA48PA-PN is suitable for 6 applications: Battery-Powered Sensor Nodes, Appliance and White-Goods Control, Prototyping and Education Platforms, Industrial Subsystem Controllers, Legacy AVR Design Maintenance, Hobby Robotics and RC Systems.
Battery-Powered Sensor Nodes
The ATMEGA48PA-PN fits battery-powered sensor nodes because the picoPower PA revision minimizes current in power-down and power-save sleep modes, while the 4KB Flash is sufficient for simple sensing, thresholding, and serial reporting firmware. A typical node uses the internal 8 MHz RC oscillator to eliminate crystal current, sleeps in power-down between ADC samples, and wakes via watchdog timer every few seconds. Because the 28-pin PDIP supports socketed assembly, engineers can iterate sensor firmware quickly during prototyping. The trade-off is program space: BLE or heavy protocol stacks will not fit in 4KB, so reserve this part for nodes using simple RF modules or wired links.
Recommended
Appliance and White-Goods Control
Appliance control boards use the ATMEGA48PA-PN for button scanning, relay/timer control, and LED indication, taking advantage of its 23 I/O lines, 8-bit and 16-bit timers, and the -40C to +105C operating range specified in the Mouser listing. The through-hole 28-PDIP package survives wave soldering and simplifies field service in high-vibration appliance environments. The ADC handles NTC thermistor reading directly, and the EEPROM stores user settings across power cycles. Designers should verify mains-isolated supply design and note that if future firmware growth is anticipated, the identical footprint accepts the ATMEGA168PA-PU or ATMEGA328P-PU with 16KB or 32KB Flash without a PCB change.
Recommended
Prototyping and Education Platforms
The ATMEGA48PA-PN is a staple for education and prototyping because the through-hole 28-pin PDIP inserts directly into breadboards and inexpensive DIP sockets, and it programs via ICSP using just two I/O pins and reset, per the Microchip product page. Students and makers benefit from the single-cycle RISC core reaching 20 MIPS at 20 MHz, which makes assembly-level teaching meaningful, while Arduino-compatible toolchains cover C development. The 131-instruction AVR set is well documented in university courses. When projects grow beyond 4KB Flash, the same footprint accepts ATMEGA328P-PU, giving a seamless migration path without rewiring a single connection.
Recommended
Industrial Subsystem Controllers
Industrial subsystems such as motor start boards, valve controllers, and monitoring nodes deploy the ATMEGA48PA-PN where its 105C-rated operation and watchdog-based robustness are required. The USART supports RS-485 networking through an external transceiver, while the analog comparator and ADC cover simple supervision tasks like over-temperature or over-current detection. Because industrial designs often remain in production for a decade or more, the documented migration path to the PB family (with Microchip's pin 3 and pin 6 cautions in application note MCU8APPS-456) provides lifecycle assurance. The PDIP package also allows socketed programming benches for factory firmware flashing.
Recommended
Legacy AVR Design Maintenance
Many existing boards were designed around the original ATmega48 and ATmega48A in 28-PDIP; the ATMEGA48PA-PN serves as the current picoPower replacement for those designs. Since the PA revision retains the same pinout, instruction set, and peripheral map, existing hex files typically run unchanged, and ICSP programming fixtures remain valid. Distributors including Rochester Electronics list the part for lifecycle support, which matters for medical, industrial, and transport equipment under regulatory change control. Engineers should confirm EEPROM wear margins and note that the PA device draws less sleep current, which is usually beneficial but should be validated in designs with brown-out detection timing assumptions.
Recommended
Hobby Robotics and RC Systems
Hobby robotics, RC receivers, servo mixers, and ESC experiments use the ATMEGA48PA-PN because its hardware timers generate precise PWM for servo and motor control, and the 20 MHz clock provides adequate loop rates for sensor fusion at this class. The 28-PDIP package tolerates repeated reprogramming and prototype abuse that would challenge fine-pitch SMD parts. With 23 I/O lines, a single DIP can drive an H-bridge, read encoders, and talk serial to a companion controller simultaneously. For designs needing USB or more memory, the same breadboard footprint accommodates the ATMEGA328P-PU, the most common hobbyist upgrade, without layout changes.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA48PA-PN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48PA-PU | ATMEGA328P-PU | ATMEGA48-20PI |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-PDIP | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Flash Memory | 4KB | 4KB | 32KB | 4KB |
| SRAM | 512 B | 512 B | 2KB | 512 B |
| EEPROM | 256 B | 256 B | 1KB | 256 B |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| picoPower (Low Power) | Yes (PA revision) | Yes | Yes | No (original revision) |
Key Differentiators
- picoPower technology (vs ATMEGA48-20PI)
- Lowest-cost entry with upgrade headroom (vs ATMEGA328P-PU)
- Through-hole PDIP for prototyping and repair (vs ATMEGA48PA-MUR)
Design Notes
Connect AVCC (pin 20) to VCC through a low-pass filter (e.g., 10uH inductor or 100R resistor with 100nF capacitor) when ADC accuracy matters; AVCC must stay within 0.3V of VCC. Decouple VCC with a 100nF ceramic directly across pins 7 and 8 and a bulk 4.7uF-10uF near the socket. Estimated: a 100nF cap placed 10 mm from the IC can add several nanohenries of parasitic inductance, so minimize trace length for best noise performance.
The PDIP footprint is forgiving, but the migration guide for the PB family flags two pins to watch: pin 3 (PD1/TXD) must not be actively driven if tied to GND, and pin 6 (PD4) must not be actively driven if tied to VCC, otherwise a future ATmega48PB drop-in may misbehave when ACO is enabled. Keeping these pins free of fixed-level connections preserves forward compatibility with the PB family. Source: Microchip online migration documentation.
The ATMEGA48PA-PN has only 4KB Flash and 512B SRAM, so avoid Arduino-core style libraries that inflate code size; use register-level or lightweight libraries. Disable unused peripherals in sleep code to realize picoPower benefits - peripherals left clocked dominate idle current. Remember the reset pin (PC6) can be reconfigured as I/O via fuse bits; leaving RSTDISBL unset is strongly advised to keep ICSP programming access. Estimated: bootloader overhead can consume 512B-1KB of the 4KB Flash if a boot section is enabled.
Compliance Information
The N package suffix denotes Microchip lead-free/RoHS-compliant PDIP per the DigiKey listing; REACH and halogen-free status not stated in the provided data.
