ATMEGA48PA-AN - 8-Bit AVR 20MHz 4KB MCU | Microchip | TQFP-32
MPN: ATMEGA48PA-AN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.42 | $1.42 |
| 10 | $1.28 | $12.80 |
| 100 | $1.09 | $109.00 |
| 500 | $0.94 | $470.00 |
| 1,000 | $0.83 | $830.00 |
ATMEGA48PA-AN Overview
An 8-bit microcontroller is a single-chip computer that integrates a CPU, program memory, data memory, and peripherals such as timers, serial interfaces, and analog-to-digital converters. Within the product hierarchy, the ATmega48PA sits in the AVR 8-bit MCU family, which belongs to the broader class of embedded microcontrollers, a subset of semiconductor integrated circuits. The picoPower architecture is designed for battery-powered and always-on embedded systems where active and sleep currents directly determine battery life.
Key features include 4 KB ISP Flash with 10,000 write/erase cycles, 256 bytes EEPROM with 100,000 write cycles, 512 bytes SRAM, 23 programmable I/O lines, and a 10-bit ADC. Three flexible timer/counters with compare and PWM modes, a USART, SPI, and TWI (I2C) interface cover most embedded communication needs. The device supports 131 powerful instructions, most executing in a single clock cycle, achieving up to 20 MIPS throughput at 20 MHz.
The ATmega48PA uses Microchip's picoPower technology, which reduces active current to approximately 0.2 mA at 1 MHz and 1.8 V, and power-down current to below 0.1 uA. The 10-bit successive-approximation ADC includes a programmable gain stage and internal temperature sensor, eliminating external analog front-end components in sensor nodes.
Typical applications include battery-powered sensor nodes, industrial control panels, consumer appliance controllers, and low-cost motor control. The wide 1.8 V to 5.5 V supply range allows direct operation from single-cell Li-Ion or 3xAA battery packs without a boost converter.
When designing with this device, decouple every VCC pin with a 100 nF ceramic capacitor placed within a few millimeters of the pin, and keep the AVCC filter inductor close to the analog supply pin. The TQFP-32 package requires careful thermal relief on the ground pads during reflow.
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 and second-sourcing decisions.
Drop-in alternatives for ATMEGA48PA-AN — 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-AN (same form factor and footprint) — differing in Serial Interfaces, Package, EEPROM, SRAM, Timer/Counters.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA48PB-AN
✅ Drop-In✓ In Stock
$0.42 / Unit
View Datasheet →ATMEGA48PA-AU
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →ATMEGA48PA-ANR
✅ Drop-In✓ In Stock
$0.98 / Unit
View Datasheet →ATMEGA88PA-AN
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA168PA-ANR
✅ Drop-In✓ In Stock
$1.44 / Unit
View Datasheet →ATMEGA48A-CCU
✅ Drop-In✓ In Stock
$1.12 / Unit
View Datasheet →ATMEGA48PA-AN Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Program Memory | 4 KB ISP Flash (2K x 16) |
| EEPROM | 256 bytes |
| SRAM | 512 bytes |
| Maximum Clock Speed | 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +105C |
| General Purpose I/O Lines | 23 |
| General Purpose Working Registers | 32 |
| Timer/Counters | 3 (two 8-bit, one 16-bit) |
| ADC Resolution | 10-bit |
| Serial Interfaces | USART, SPI, TWI (I2C) |
| Instruction Set | 131 instructions, most single-cycle |
| Flash Endurance | 10,000 write/erase cycles |
| EEPROM Endurance | 100,000 write/erase cycles |
| Package | 32-TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATMEGA48PA-AN Pin Configuration
| Pin 1 | PD3 — Port D bit 3 / INT1 / OC2B |
| Pin 2 | PD4 — Port D bit 4 / T0 / XCK |
| 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 |
| Pin 8 | PB7 — Port B bit 7 / XTAL2 / TOSC2 |
| Pin 9 | PD5 — Port D bit 5 / T1 / OC0B |
| Pin 10 | PD6 — Port D bit 6 / AIN0 / OC0A |
| Pin 11 | PD7 — Port D bit 7 / AIN1 |
| Pin 12 | PB0 — Port B bit 0 / ICP1 / CLKO |
| Pin 13 | PB1 — Port B bit 1 / OC1A |
| Pin 14 | PB2 — Port B bit 2 / SS / OC1B |
| Pin 15 | PB3 — Port B bit 3 / MOSI / OC2A |
| Pin 16 | PB4 — Port B bit 4 / MISO |
| Pin 17 | PB5 — Port B bit 5 / SCK |
| Pin 18 | AVCC — Analog supply voltage |
| Pin 19 | ADC6 — Analog input channel 6 |
| Pin 20 | AREF — Analog reference voltage |
| 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 |
| Pin 28 | PC5 — Port C bit 5 / ADC5 / SCL |
| Pin 29 | RESET — Reset input (active low) |
| Pin 30 | PD0 — Port D bit 0 / RXD |
| Pin 31 | PD1 — Port D bit 1 / TXD |
| Pin 32 | PD2 — Port D bit 2 / INT0 |
Typical Applications
ATMEGA48PA-AN is suitable for 6 applications: Battery-Powered Sensor Nodes, Industrial Control Panels, Consumer Appliance Controllers, Low-Cost Motor Control, Portable Medical Monitors, Smart Home and IoT Devices.
Battery-Powered Sensor Nodes
The ATMEGA48PA-AN fits battery-powered sensor nodes because its picoPower architecture draws approximately 0.2 mA at 1 MHz and 1.8 V in active mode and below 0.1 uA in power-down mode, directly extending battery life in always-on wireless sensing. The 1.8 V to 5.5 V supply range allows direct operation from a single Li-Ion cell or a 3xAA pack without a boost converter, simplifying the power tree. In a typical node, the MCU wakes from power-down on a timer interrupt, samples a sensor through the 10-bit ADC, and transmits over USART or SPI to a radio module. The trade-off is that at 1.8 V the maximum clock is limited to roughly 4 MHz, so designers must balance throughput against supply headroom.
Recommended
Industrial Control Panels
The ATMEGA48PA-AN suits industrial control panels because its -40C to +105C temperature rating and 5.5 V maximum supply provide margin in electrically noisy factory environments. The 23 general-purpose I/O lines drive relays, optocouplers, and status LEDs directly, while three timer/counters generate the PWM and timing signals needed for motor and valve control. In a typical panel, the MCU scans pushbuttons and limit switches, debounces inputs in firmware, and updates outputs through a shift register or port expander. The trade-off is that 4 KB of Flash limits the control algorithm complexity, so panels with extensive HMI logic should migrate to the pin-compatible ATmega88PA or ATmega168PA.
Recommended
Consumer Appliance Controllers
The ATMEGA48PA-AN is used in consumer appliance controllers because its 4 KB Flash and 512 bytes SRAM are sufficient for keypad scanning, display multiplexing, and motor sequencing in products such as coffee makers, washing machines, and air purifiers. The integrated 10-bit ADC reads thermistors and current-sense shunts without external analog components, reducing BOM cost. In a typical design, the MCU runs a state machine that reads user inputs, drives a triac or relay, and monitors a temperature sensor for overheat protection. The trade-off is that the 32-pin TQFP requires a two-layer PCB with adequate ground plane for noise immunity, unlike a DIP alternative.
Recommended
Low-Cost Motor Control
The ATMEGA48PA-AN supports low-cost motor control because its three timer/counters generate complementary PWM outputs for H-bridge and three-phase inverter topologies, and the 10-bit ADC samples current-sense and back-EMF signals for commutation. At 20 MHz the core delivers up to 20 MIPS, enough for a 10 kHz PWM loop with sensorless BLDC commutation. In a typical design, the MCU implements a PI speed loop, reads a Hall sensor or back-EMF divider, and updates the PWM duty cycle each period. The trade-off is that 4 KB Flash constrains the control algorithm, so field-oriented control designs should use the pin-compatible ATmega168PA.
Recommended
Portable Medical Monitors
The ATMEGA48PA-AN is used in portable medical monitors because its 10-bit ADC with programmable gain digitizes ECG, pulse-oximetry, and temperature signals, while the 1.8 V to 5.5 V supply allows direct operation from a rechargeable battery. The 105C temperature rating supports sterilization and warm-environment operation, and the low power-down current preserves battery during transport. In a typical monitor, the MCU samples the analog front end at 1 kHz, filters the data in firmware, and streams results over USART to a display or Bluetooth module. The trade-off is that 4 KB Flash limits on-device signal processing, so advanced filtering should be offloaded to a companion DSP.
Recommended
Smart Home and IoT Devices
The ATMEGA48PA-AN fits smart home and IoT devices because its USART, SPI, and TWI interfaces connect directly to Wi-Fi, Zigbee, and BLE modules without glue logic, and the 23 I/O lines handle buttons, LEDs, and relay drivers. The picoPower architecture keeps average current low enough for coin-cell and battery-assisted operation, while the 1.8 V to 5.5 V range accommodates both 3.3 V radios and 5 V legacy peripherals. In a typical design, the MCU runs a sensor-polling loop, formats data packets, and hands them to the radio over SPI. The trade-off is that 4 KB Flash limits protocol stack size, so devices needing full TCP/IP should use a higher-Flash AVR.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA48PA-AN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48PB-AN | ATMEGA48PA-AU | ATMEGA88PA-AN | ATMEGA168PA-AN |
|---|---|---|---|---|---|
| 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 bytes | 512 bytes | 512 bytes | 1 KB | 1 KB |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 512 bytes | 512 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 | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Operating Temperature | -40C to +105C | -40C to +105C | -40C to +85C | -40C to +105C | -40C to +105C |
| General Purpose I/O | 23 | 23 | 23 | 23 | 23 |
| Serial Interfaces | USART, SPI, TWI | USART (improved), SPI, TWI | USART, SPI, TWI | USART, SPI, TWI | USART, SPI, TWI |
Key Differentiators
- Extended 105C temperature rating (vs ATMEGA48PA-AU)
- Pin-compatible migration path to higher Flash (vs ATMEGA88PA-AN)
- Documented drop-in successor with added features (vs ATMEGA48PB-AN)
- picoPower low-current operation (vs ATMEGA48A-CCU)
Design Notes
Decouple every VCC pin (pins 4 and 6) with a 100 nF ceramic capacitor placed within a few millimeters of the pin, and add a 10 uF bulk capacitor near the package. The AVCC pin (pin 18) requires a separate low-pass filter, typically a 10 uH inductor in series with a 100 nF capacitor to GND, to isolate the analog supply from digital switching noise. According to the Microchip ATmega48PA datasheet, AVCC must not differ from VCC by more than 0.3 V to keep the ADC within specification.
Route the 32-TQFP ground pins (3, 5, and 21) to a solid ground plane with short, wide traces, and use thermal relief spokes on the pads to ensure reliable reflow. Keep the crystal or resonator traces between XTAL1 (pin 7) and XTAL2 (pin 8) as short as possible and guard them with ground, since the oscillator loop is sensitive to capacitive coupling. Place the 22 pF load capacitors directly at the crystal pins and avoid routing any switching signals beneath the oscillator area.
Do not leave the RESET pin (pin 29) floating; add a 10 kOhm pull-up to VCC and a 100 nF capacitor to GND for reliable power-on reset. If the analog comparator is unused, disable it in firmware to reduce current consumption. When migrating to the pin-compatible ATmega48PB, Microchip application note MCU8APPS-456 warns that pin 3 must not be actively driven if connected to GND and pin 6 must not be actively driven if connected to VCC, otherwise the analog comparator can drive a pin unexpectedly.
Estimated: the ATmega48PA-AN dissipates roughly 5 mW at 1 MHz and 1.8 V (about 0.2 mA active current), rising to approximately 25 mW at 20 MHz and 5 V. With a TQFP-32 theta_JA near 60 C/W, the junction rise above ambient is under 2 C at typical loads, so no heatsinking is required. These figures are estimates based on datasheet current curves, not guaranteed maximums; verify against the electrical characteristics table for worst-case designs.
Compliance Information
DigiKey and Mouser list the ATMEGA48PA-AN as RoHS compliant and lead-free. The part is not AEC-Q100 qualified; automotive designs should evaluate the ATMEGA48PA-15MZ automotive-grade variant. REACH, halogen-free, and conflict-minerals status were not stated in the retrieved data.
