ATMEGA48P-20MUR - 8-bit AVR MCU 20MHz 4KB Flash | Microchip
MPN: ATMEGA48P-20MUR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.42 | $142.00 |
| 500 | $1.24 | $620.00 |
| 1,000 | $1.06 | $1,060.00 |
ATMEGA48P-20MUR Overview
A microcontroller (MCU) is a single integrated circuit that combines a processor core, memory, and programmable peripherals into one chip, sitting at the top of the embedded control hierarchy that spans from discrete logic to full system-on-chip devices. The ATmega family, originally developed by Atmel and now manufactured by Microchip Technology, is one of the most widely deployed 8-bit MCU families in the industry, using the AVR enhanced RISC architecture with 131 powerful instructions, most executing in a single clock cycle.
Key features include 23 general-purpose I/O lines, three flexible timer/counters with compare modes, a 10-bit ADC, SPI and TWI (I2C) serial interfaces, and internal calibrated RC oscillator options that reduce external component count. The picoPower technology enables low-power sleep modes for battery-sensitive designs.
The device offers in-system programmable (ISP) Flash and is supported by Microchip MPLAB tools, including the MPLAB SNAP debugger with In-Circuit Serial Programming (ICSP) via two I/O pins and the reset line. The 32-VQFN (5x5 mm), 0.45 mm pitch, 1 mm height green package suits compact, space-constrained industrial boards.
Typical applications include industrial automation sensor nodes, consumer appliance control, hobby and maker boards, and battery-powered metering products where a 5 V rail and moderate memory footprint are sufficient.
When designing with this part, note that at 20 MHz operation the supply must stay within 4.5 V to 5.5 V; lower voltage operation requires derating the clock frequency.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for ATMEGA48P-20MUR 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 ATMEGA48P-20MUR (same form factor and footprint) β differing in Package, Operating Temperature, Supply Voltage Range, Communication Interfaces, Flash Memory.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA48P-20MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA48-20MUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA48PA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.08 / Unit
View Datasheet βATMEGA88P-20MU
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA168PA-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.72 / Unit
View Datasheet βATMEGA328P-MU
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.28 / Unit
View Datasheet βATMEGA48P-20MUR Maximum Ratings & Electrical Characteristics
| Core Architecture | AVR 8-bit RISC |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 4 KB (2K x 16) |
| EEPROM | 256 B |
| SRAM | 512 B |
| Supply Voltage Range | 4.5 V to 5.5 V (at 20 MHz) |
| General Purpose I/O | 23 |
| Timer/Counters | 3 (with compare modes) |
| Serial Interfaces | SPI, TWI (I2C), USART |
| ADC | 10-bit |
| Package | 32-VQFN (5x5 mm), 0.45 mm pitch, 1 mm height |
| Mounting Type | Surface Mount |
| Operating Temperature | Industrial range (-40C to +85C) |
| Life Cycle Stage | Active |
| Green / RoHS Package | Green (halogen-free) plastic package |
| Programming / Debug | ISP, ICSP via MPLAB SNAP |
| Low Power Technology | picoPower |
ATMEGA48P-20MUR green (halogen-free) plastic package Pin Configuration Guide
Pin configuration for ATMEGA48P-20MUR (green (halogen-free) plastic package package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA48P-20MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA48P-20MUR is suitable for 6 applications: Industrial Automation and Sensor Nodes, Appliance and Consumer Control Boards, Battery-Powered Metering and Monitoring, Maker, Hobby and Educational Boards, LED Lighting and Dimming Control, Motor Control and Small Actuator Drivers.
Industrial Automation and Sensor Nodes
The ATMEGA48P-20MUR fits industrial sensor acquisition nodes because its 10-bit ADC, SPI, and TWI interfaces directly connect to common sensors and EEPROM/FRAM peripherals, while 23 GPIO lines handle relay drivers, LEDs, and limit switches without glue logic. Its industrial temperature rating and 5 V noise immunity suit electrically noisy factory floors where 3.3 V MCUs require extra level shifting. The 20 MHz RISC core executes 131 mostly single-cycle instructions, giving deterministic timing for polling loops and simple PID control. Designers typically place the MCU between a 5 V DIN-rail supply and peripheral connectors, using the internal watchdog and brown-out detector for fault recovery; the main trade-off is the 512 B SRAM limit, which caps buffering for high-rate data streams.
Recommended
Appliance and Consumer Control Boards
White-goods and small-appliance control boards commonly use ATmega48-class MCUs for keypad scanning, display multiplexing, and relay or triac control. The ATMEGA48P-20MUR provides three timer/counters with compare modes for PWM-driven heater or motor control and buzzer tone generation, while TWI manages RTC and temperature-sensor chips. The 32-pad VQFN 5x5 mm footprint with 0.45 mm pitch fits cost-sensitive single-layer-dense layouts, and the green package meets mainstream environmental regulations. At a 20 MHz full-speed 5 V supply it drives robust logic levels directly. The picoPower sleep modes allow 'standby' appliance states with sub-milliamp draw. Firmware under 4 KB is typical for these products; if the code base grows, the pin-compatible ATMEGA88P or ATMEGA328P avoids any PCB respin.
Recommended
Battery-Powered Metering and Monitoring
For 5 V or regulated battery-backed meters (energy, water, level), the ATMEGA48P-20MUR's picoPower sleep modes and wake-on-interrupt sources keep average consumption low between periodic ADC measurements. The 10-bit ADC plus the extra ADC6/ADC7 pads available on the 32-pad package provide multiple analog inputs without an external multiplexer, and the 256 B EEPROM stores calibration constants through power cycles. USART links to RS-485 or M-Bus transceivers for remote reading. A typical topology places a low-quiescent LDO ahead of the MCU and uses timer interrupts to wake, sample, compute, and sleep. Designers must budget the 512 B SRAM carefully for packet buffers; the 20 MHz clock permits fast wake-compute-sleep cycles that minimize duty-cycle energy.
Recommended
Maker, Hobby and Educational Boards
The ATmega48 family is a staple of embedded-systems education and hobby designs because the AVR architecture is simple, free toolchains are mature, and the part is inexpensive. The ATMEGA48P-20MUR's 32-pad VQFN is breadboard-hostile, so hobby boards typically mount it on a small carrier PCB exposing the 23 I/O lines to 0.1-inch headers. Programming uses ICSP over two I/O pins plus RESET via USBasp or MPLAB SNAP, teaching fuse configuration, ISP, and bootloader concepts. The 20 MHz capability with an external crystal demonstrates oscillator design, while the internal RC oscillator enables crystal-less quick builds. The 4 KB Flash comfortably hosts classic exercises such as UART terminals, servo controllers, and SPI/TWI sensor demos, making it a low-risk first VQFN assembly project.
Recommended
LED Lighting and Dimming Control
Mains-powered LED drivers and RGB controllers use the ATMEGA48P-20MUR for its hardware PWM: the three timer/counters with compare modes generate phase-correct or fast PWM on multiple channels simultaneously at 20 MHz resolution, enabling flicker-free dimming. The 5 V rail available in many lighting power supplies (via a small buck from the main rail) matches the 4.5 V to 5.5 V operating window directly, removing an extra regulator stage. TWI allows wall-panel dimmer communication, and the 10-bit ADC reads potentiometer or NTC feedback for closed-loop thermal protection of LED boards. The VQFN 5x5 mm package fits compact driver PCBs inside luminaire housings, and hardware PWM continues during sleep-mode transitions for smooth brightness ramps.
Recommended
Motor Control and Small Actuator Drivers
Fan, pump, and small DC-motor controllers benefit from the ATMEGA48P-20MUR's compare-mode timers for complementary PWM generation and its interrupt inputs for hall-sensor or tachometer feedback. At 20 MHz the 8-bit core closes simple PI speed loops at kilohertz rates with cycle-accurate ISR latency, sufficient for single-motor applications. The 5 V supply domain interfaces cleanly with gate-driver and MOSFET-driver ICs, and the 10-bit ADC samples current-shunt amplifiers for overload protection. The 32-pad VQFN (5x5 mm) keeps the controller footprint small on driver boards where the power stage dominates area. Firmware stays small (closed-loop speed control typically under 2 KB), fitting the 4 KB Flash comfortably, with the 256 B EEPROM holding speed profiles and fault logs across power cycles.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA48P-20MUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48P-20MU | ATMEGA48-20MUR | ATMEGA48PA-MU | ATMEGA88P-20MU | ATMEGA328P-MU |
|---|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same | 32-VQFN (5x5 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 4 KB | 4 KB | 4 KB | 4 KB | 8 KB | 32 KB |
| SRAM | 512 B | 512 B | 512 B | 512 B | 1 KB | 2 KB |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 512 B | 1 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| picoPower Technology | Yes | Yes | No (pre-picoPower) | Yes | Yes | Yes |
| Packaging / Suffix | Tape & Reel (R) | Tray (no R suffix) | Tape & Reel (R) | Tray / reel variants exist | Tray / reel variants exist | Tray / reel variants exist |
Key Differentiators
- picoPower technology for lower sleep current (vs ATMEGA48-20MUR)
- Lowest cost entry point in the 32-VQFN megaAVR lineup (vs ATMEGA328P-MU)
- Trade-off: smallest memory in the family (vs ATMEGA88P-20MU)
Design Notes
At 20 MHz operation the ATMEGA48P-20MUR must be supplied within 4.5 V to 5.5 V; the AVR family derates maximum safe clock as VCC falls. Decouple VCC and AVCC separately: place 100 nF ceramic capacitors at each pin with a 10 uF bulk capacitor nearby, and connect AVCC to VCC through an LC or RC filter when ADC accuracy matters. Use the internal brown-out detector (BOD) fuse so the MCU holds reset during supply sag, preventing EEPROM corruption during writes. Estimated: a 20 MHz ATmega draws roughly 10-15 mA active at 5 V, so a simple 100 mA LDO suffices for MCU-only boards.
The 32-pad VQFN (5x5 mm, 0.45 mm pitch) requires a correct land pattern and exposed-pad thermal connection. The center pad on ATmega MLF packages is the ground die-attach; connect it to the GND plane via a 4x4 via array (approximately 0.3 mm drills) to improve grounding and heat spreading. Use 0.2-0.25 mm trace widths for fanout under the 0.45 mm pitch leads and prefer via-in-pad or dogbone fanout consistently. For first-time VQFN assembly, verify stencil aperture design (typically 70-80% pad coverage) to avoid solder bridging between the fine-pitch leads.
Fuse misconfiguration is the most common failure with ATmega48 designs: selecting an external crystal clock fuse without a working oscillator, or disabling the RESET pin as GPIO (RSTDISBL), can permanently lock the device from further ISP programming. Always set CKOPT/clock fuses incrementally and test re-programmability after each change. Also note the 4 KB Flash leaves limited room for a bootloader; most designs flash via ICSP instead. When migrating from ATMEGA48P to ATMEGA48PA, recompile and review the errata and power-management register differences rather than assuming bit-level identity.
Compliance Information
Package described in specification data as GREEN plastic (halogen-free), industrial temperature rating. Not an automotive AEC-Q100 device. Obtain formal RoHS/REACH certificates from Microchip for regulatory submissions.
