ATMEGA48PB-MNR - 8-bit AVR MCU 4KB Flash 20MHz QFN-32 | Microchip
MPN: ATMEGA48PB-MNR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.37 | $1.37 |
| 10 | $1.24 | $12.40 |
| 100 | $1.09 | $109.00 |
| 500 | $0.98 | $490.00 |
| 1,000 | $0.88 | $880.00 |
ATMEGA48PB-MNR Overview
A microcontroller unit (MCU) is a single-chip computer that combines a processor core, program memory, data memory, and peripherals on one die. The ATmega48PB belongs to the AVR ATmega family of 8-bit RISC microcontrollers, which sits within the broader embedded processor hierarchy used across consumer, industrial, and automotive electronics. AVRs execute most instructions in a single clock cycle, delivering high code density and deterministic timing for real-time embedded control.
Key features include the advanced AVR RISC architecture with 32 general-purpose working registers, three flexible timer/counters with compare modes and PWM outputs, and connectivity via I2C (TWI), SPI, and UART/USART. On-chip peripherals include brown-out detection and reset, power-on reset, and a watchdog timer. The picoPower technology platform supports sleep modes with very low standby consumption, making the part suited to battery-powered designs. The MNR suffix denotes the RoHS-green, 105C-rated, tape-and-reel 32-VFQFN variant, and the device is listed with Functional Safety (FuSa) support documentation by Microchip.
Technical depth: the 4KB Flash supports read-while-write and in-system self-programming, enabling field firmware updates without a separate external memory. The 2.5V/3.3V/5V operating range (per distributor parametric data) allows direct operation from a single Li-ion cell, a 3.3V rail, or a 5V industrial supply. The USART supports wake-up on start of transmission, and the byte-oriented TWI interface supports I2C sensor networks at up to 400kHz.
Typical applications include industrial sensor nodes and HMI controllers, battery-powered IoT and consumer devices, and motor control or LED lighting systems that use the hardware PWM channels with brown-out protection for safe operation.
Design consideration: budget 4KB Flash carefully - linker statistics and library overhead can consume the space quickly, so consider the pin-compatible ATmega88PB or ATmega328PB (8KB/16KB) within the same PB family if firmware growth is expected.
This page synthesizes verified distributor pricing, drop-in family alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet. Pricing shown as of 2026-09-18.
Drop-in alternatives for ATMEGA48PB-MNR 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 ATMEGA48PB-MNR (same form factor and footprint) β differing in Package, Flash Memory, EEPROM, SRAM, ADC.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA48PB-AN
β Drop-Inβ In Stock
$0.42 / Unit
View Datasheet βATMEGA48PA-MMNR
β Drop-Inβ In Stock
$1.33 / Unit
View Datasheet βATMEGA48PA-MMH
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA48P-20MMU
β Drop-Inβ In Stock
$0.1698 / Unit
View Datasheet βATMEGA88PB-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.98 / Unit
View Datasheet βATMEGA328PB-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.68 / Unit
View Datasheet βATMEGA48PB-MNR Maximum Ratings & Electrical Characteristics
| Core Processor | AVR |
| Core Size | 8-bit |
| Maximum Clock Frequency | 20 MHz |
| Program Memory Size | 4 KB (2K x 16) Flash |
| Program Memory Type | FLASH (ISP, read-while-write) |
| EEPROM Size | 256 B |
| SRAM Size | 512 B |
| Number of I/O | 27 |
| Supply Voltage Range | 2.5 V / 3.3 V / 5 V operation |
| Connectivity | I2C (TWI), SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Timers | Three flexible timer/counters with compare modes |
| Operating Temperature | -40C to +105C |
| Package | 32-VFQFN (5x5 mm) Exposed Pad |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (MNR suffix), GREEN/RoHS |
| Special Features | picoPower technology, Functional Safety (FuSa) support |
ATMEGA48PB-MNR Pin Configuration
| Pin 1 | PD3 β Port D bit 3 (GPIO / INT1) |
| Pin 2 | PD4 β Port D bit 4 (GPIO / XCK/T0) |
| Pin 3 | GND β Ground (see PA-to-PB migration caution: if tied to GND, must not be actively driven) |
| Pin 4 | VCC β Digital supply voltage |
| Pin 5 | GND β Ground |
| Pin 6 | VCC β Digital supply voltage (see PA-to-PB migration caution: if tied to VCC, must not be actively driven) |
| Pin 7 | PB6 β Port B bit 6 (GPIO / XTAL1 / TOSC1) |
| Pin 8 | PB7 β Port B bit 7 (GPIO / XTAL2 / TOSC2) |
| Pin 9 | PD5 β Port D bit 5 (GPIO / T1 / OC0B) |
| Pin 10 | PD6 β Port D bit 6 (GPIO / AIN0 / OC0A) |
| Pin 11 | PD7 β Port D bit 7 (GPIO / AIN1) |
| Pin 12 | PB0 β Port B bit 0 (GPIO / ICP1 / OC1A) |
| Pin 13 | PB1 β Port B bit 1 (GPIO / OC1A) |
| Pin 14 | PB2 β Port B bit 2 (GPIO / SS / OC1B) |
| Pin 15 | PB3 β Port B bit 3 (GPIO / MOSI / OC2A) |
| Pin 16 | PB4 β Port B bit 4 (GPIO / MISO) |
| Pin 17 | PB5 β Port B bit 5 (GPIO / SCK) |
| Pin 18 | AVCC β ADC supply voltage |
| Pin 19 | ADC6 β ADC input channel 6 |
| Pin 20 | AREF β Analog reference voltage |
| Pin 21 | GND β Ground |
| Pin 22 | ADC7 β ADC input channel 7 |
| Pin 23 | PC0 β Port C bit 0 (GPIO / ADC8 / SCL) |
| Pin 24 | PC1 β Port C bit 1 (GPIO / ADC9 / SDA) |
| Pin 25 | PC2 β Port C bit 2 (GPIO / ADC10 / TCK) |
| Pin 26 | PC3 β Port C bit 3 (GPIO / ADC11 / TMS) |
| Pin 27 | PC4 β Port C bit 4 (GPIO / ADC12 / TDO) |
| Pin 28 | PC5 β Port C bit 5 (GPIO / ADC13 / TDI) |
| Pin 29 | PC6 β Port C bit 6 (GPIO / RESET) |
| Pin 30 | PD0 β Port D bit 0 (GPIO / RXD) |
| Pin 31 | PD1 β Port D bit 1 (GPIO / TXD) |
| Pin 32 | PD2 β Port D bit 2 (GPIO / INT0) |
Typical Applications
ATMEGA48PB-MNR is suitable for 6 applications: Industrial Sensor Nodes, Battery-Powered Consumer and IoT Devices, Motor Control and PWM Lighting, HMI and User Interface Controllers, Wired Communication Bridges and Protocol Converters, Safety-Oriented Embedded Control.
Industrial Sensor Nodes
The ATMEGA48PB-MNR fits industrial sensor nodes because its I2C (TWI) and SPI interfaces connect directly to pressure, temperature, and humidity sensors, while the 105C-rated MNR variant survives control-cabinet ambient temperatures. The brown-out detector and watchdog timer guarantee recovery from supply dips caused by inductive loads, and picoPower sleep modes cut average current in duty-cycled monitoring nodes. Placed between a 3.3V or 5V rail and the sensor bus with hardware TWI at 400kHz, it samples and buffers readings in its 512B SRAM before burst transmission over USART or RF. The trade-off is the 4KB Flash budget, which constrains protocol stacks to lightweight implementations.
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Battery-Powered Consumer and IoT Devices
For battery-powered devices, the ATMEGA48PB-MNR's picoPower technology provides deep sleep modes where the asynchronous timer or pin-change interrupt wakes the core, minimizing standby drain on coin cells. Operating down to the 2.5V range (per distributor parametric data) allows direct use from a lithium coin cell through most of its discharge curve, eliminating a boost converter. The 27 I/O lines drive keys, LEDs, and a segment LCD-free UI, while the watchdog timer resets a hung firmware loop before battery waste occurs. Designers must account for the 4KB Flash ceiling when adding wireless stacks, typically offloading connectivity to a companion module over UART.
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Motor Control and PWM Lighting
The ATMEGA48PB-MNR suits small motor and LED lighting control because its three timer/counters generate hardware PWM with compare modes, producing glitch-free outputs independent of firmware timing jitter. The 20MHz clock supports 8-bit PWM at roughly 78kHz, above audible range for fan and backlight applications. Brown-out detection ensures PWM outputs are safely tri-stated during supply sag, protecting MOSFET gate stages, and the exposed-pad VFQFN package conducts heat from the die during high switching activity. Gate-drive outputs pair naturally with logic-level MOSFETs; keep sense resistors within the ADC range and use the 10-bit ADC for current feedback loops.
Recommended
HMI and User Interface Controllers
As a dedicated HMI controller, the ATMEGA48PB-MNR scans keypads, drives LEDs and indicators, and manages a UART link to a main processor, offloading UI latency from the host. The 27 GPIO lines handle a 4x4 matrix plus status outputs, and pin-change interrupts wake the MCU instantly on keypress for responsive interaction from sleep. Hardware SPI can drive OLED or TFT display modules, while the byte-oriented TWI interface reads capacitive touch controllers. Its 105C rating suits appliances and automotive-adjacent cockpit pods. The 4KB Flash accommodates display drivers and debouncing logic, though complex graphics rendering should remain on the host or a dedicated display controller.
Recommended
Wired Communication Bridges and Protocol Converters
The ATMEGA48PB-MNR works as a compact protocol bridge using its USART, SPI, and TWI interfaces concurrently - for example converting RS-232/UART telemetry into an I2C sensor network, or forwarding SPI device data onto a longer-reach UART line. The USART wake-up on start of transmission feature lets the bridge stay in sleep until traffic arrives, cutting idle power in continuously wired systems. At 20MHz, the AVR services 115200-baud UART with generous interrupt headroom and a double-buffered receive path. Designers should verify FIFO depth against worst-case burst traffic since the 512B SRAM bounds buffering; hardware flow control on the USART mitigates overrun risk.
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Safety-Oriented Embedded Control
Microchip lists the ATmega48PB as a Functional Safety (FuSa) supported device, making the ATMEGA48PB-MNR appropriate for control paths where documented failure modes and safety collateral are required - such as interlocks, e-stop supervision logic, and appliance safety monitoring. Layered hardware protections support this role: the power-on reset guarantees known register states at startup, the programmable brown-out detector holds the MCU in reset through supply sag, and the independent watchdog timer recovers from software lockup. Firmware can add periodic RAM and Flash self-checks within the 4KB budget. Full safety certification depends on system-level analysis using Microchip's safety documentation package, not the component alone.
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Recommended Products Summary
Engineering reference data for ATMEGA48PB-MNR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48PB-AN | ATMEGA48PA-MMNR | ATMEGA48P-20MMU | ATMEGA88PB-MUR | ATMEGA328PB-MUR |
|---|---|---|---|---|---|---|
| Package | 32-VFQFN (5x5) Exposed Pad | 32-VFQFN (5x5) Exposed Pad - same | 32-VFQFN (5x5) Exposed Pad - same | 32-VFQFN (5x5) Exposed Pad - same | 32-VFQFN (5x5) Exposed Pad - same | 32-VFQFN (5x5) Exposed Pad - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 4 KB (2K x 16) | 4 KB | 4 KB | 4 KB | 8 KB | 16 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 | 512 B |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Special Features | picoPower, FuSa support | picoPower, FuSa support | picoPower (PA generation) | picoPower (P generation) | picoPower, FuSa support | picoPower, extra USART/TWI/timers |
Key Differentiators
- Functional Safety (FuSa) documentation support (vs ATMEGA48PA-MMNR)
- 105C industrial temperature rating on MNR variant (vs ATMEGA48PA-MMNR)
- Same-footprint firmware growth path (vs ATMEGA88PB-MUR / ATMEGA328PB-MUR)
- Cost floor vs larger family members (vs ATMEGA328PB-MUR)
Design Notes
The exposed die pad on the 32-VFQFN (5x5 mm) package is the primary ground connection and must be soldered to a contiguous ground plane with an array of thermal vias (typically 3x3 to 4x4 via pattern per Microchip MLF/QFN application guidance). Insufficient pad soldering causes intermittent GND faults and elevated junction temperature. Inspect with X-ray or 2D solder inspection on production builds, since voiding under QFN pads is a leading field-failure cause for this package family.
Place a 100 nF ceramic decoupling capacitor directly across the VCC pins (pins 4 and 6) and AVCC (pin 18), with an additional 10 uF bulk capacitor near the supply entry. AVCC must be connected to VCC through an LC filter (e.g., 10 uH + 100 nF) when ADC accuracy matters, or tied directly when analog noise is not critical. Never leave AVCC floating - the ADC and port C fail to operate correctly. Follow Microchip's AVR hardware design application notes for supply layout.
When substituting the ATMEGA48PB for an ATMEGA48PA on an existing board, respect the two documented migration conditions from Microchip: pin 3, if connected to GND, must not be actively driven (and ACO must not be enabled), and pin 6, if connected to VCC, must not be actively driven. Also verify RESET (pin 29) polarity and debugWIRE settings - a fuse set for debugWIRE disables external reset and can lock out ISP programming if no debugWIRE-capable tool is available.
Keep the crystal (PB6/PB7, pins 7-8) within 10 mm of the MCU with short ground-guard traces, and route USART (PD0/PD1) away from the ADC input traces (ADC6/ADC7, pins 19 and 22) to minimize digital-to-analog coupling. The 20MHz system clock produces harmonics into the HF range; a solid ground plane under the QFN and short return paths for high-current PWM outputs (OC0A/OC0B/OC1A/OC1B) reduce EMI ahead of EMC pre-compliance testing.
Enable the internal pull-ups on unused floating GPIO and configure unused pins as inputs with pull-up (per Microchip AVR best practice) to prevent floating-input oscillation, which increases supply current in sleep modes by several microamps. For SPI lines above 8MHz, keep traces under 50 mm and add 22-33 ohm series resistors on SCK and MOSI to tame ringing. The TWI bus requires external pull-up resistors sized for the bus capacitance - 4.7 kohm is typical at 3.3V with under 200 pF bus load.
Compliance Information
Mouser listing identifies the part as 'GREEN', indicating lead-free/halogen-free RoHS-compliant construction. AEC-Q100 status not stated in provided data; the device targets industrial (105C) rather than automotive qualification.
