ATMEGA48PB-AN - 8-Bit AVR MCU 20MHz 4KB TQFP-32 | Microchip
MPN: ATMEGA48PB-AN ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.55 | $0.55 |
| 10 | $0.52 | $5.20 |
| 100 | $0.48 | $48.00 |
| 500 | $0.45 | $225.00 |
| 1,000 | $0.42 | $420.00 |
ATMEGA48PB-AN Overview
An 8-bit AVR microcontroller is a self-contained computing device that combines a RISC processor core, program memory (Flash), data memory (SRAM and EEPROM), and peripherals such as timers, USART, SPI, TWI (I2C), and a 10-bit ADC on a single chip. In the broader power-management and embedded-systems hierarchy, it sits at the low-end of the ATmega family, above tinyAVR parts and below the ATmega88PB/168PB/328PB siblings, all of which share the same pinout philosophy and development ecosystem.
Key features include 20 MHz maximum clock frequency across the full 2.5V to 5.5V operating range (with 1.8V operation at reduced speed), three flexible timer/counters with compare modes, a USART with wake-up on start of transmission, byte-oriented TWI and SPI serial interfaces, and in-circuit serial programming (ICSP) via two I/O pins and the reset line. The PB silicon revision adds enhanced analog and peripheral functionality over the PA generation while remaining pin-compatible in the 32-pin TQFP package.
Architecturally, the ATmega48PB uses a Harvard-architecture AVR RISC core with 32 general-purpose working registers directly connected to the ALU, allowing two independent registers to be accessed in one instruction. picoPower technology provides multiple sleep modes, including power-down and power-save, enabling battery-operated designs with microamp-level standby current.
Typical applications include industrial sensor nodes, lighting and HVAC control, consumer appliances, and functional-safety-oriented designs (the device is offered with FuSa support documentation), where the -40C to +105C industrial temperature range and low-cost 4 KB flash footprint fit cost-sensitive embedded control.
Design consideration: use decoupling capacitors close to VCC/AVCC and verify the two pins with modified functionality (pin 3 and pin 6) if migrating from ATmega48PA hardware, per Microchip migration application note 00002602A.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA48PB-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 ATMEGA48PB-AN (same form factor and footprint) — differing in Package, EEPROM, RoHS Status, SRAM, Serial Interfaces.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATMEGA48PB-AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA48PA-AU
✅ Drop-In✓ In Stock
$1.38 / Unit
View Datasheet →ATMEGA48PA-AUR
✅ Drop-In✓ In Stock
$1.72 / Unit
View Datasheet →ATMEGA48PA-AN
✅ Drop-In✓ In Stock
$0.83 / Unit
View Datasheet →ATMEGA88PB-AU
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
ATMEGA168PB-AU
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.27 / Unit
View Datasheet →ATMEGA48PB-AN Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Maximum Clock Frequency | 20 MHz |
| Flash Memory | 4 KB (2K x 16) |
| EEPROM | 256 B |
| SRAM | 512 B |
| General-Purpose I/O | 27 lines |
| Supply Voltage Range | 2.5 V to 5.5 V (1.8 V at reduced speed) |
| Operating Temperature | -40C to +105C |
| Package | 32-TQFP, 7x7 mm (package code AN) |
| Timers/Counters | 3 (with compare modes) |
| USART | 1 (wake-up on start of transmission) |
| Serial Interfaces | SPI, TWI (I2C-compatible) |
| Low-Power Technology | picoPower |
| Programming | ISP Flash with read-while-write, ICSP via 2 I/O pins + reset |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| Green Status | GREEN (lead-free per Mouser listing) |
| Functional Safety | FuSa support offered by Microchip |
ATMEGA48PB-AN Pin Configuration
| Pin 1 | PC6 / RESET — Port C bit 6 or active-low reset input |
| Pin 2 | PD0 / RXD — Port D bit 0, USART receive |
| Pin 3 | PD1 / TXD — Port D bit 1, USART transmit (modified functionality vs PA - see migration note: do not actively drive if tied to GND) |
| Pin 4 | PD2 / INT0 — Port D bit 2, external interrupt 0 |
| Pin 5 | PD3 / INT1 — Port D bit 3, external interrupt 1 / OC2B |
| Pin 6 | PD4 — Port D bit 4 / timer function (modified functionality vs PA - do not actively drive if tied to VCC) |
| Pin 7 | VCC — Digital supply voltage |
| Pin 8 | GND — Ground |
| Pin 9 | PB6 / XTAL1 — Port B bit 6 or crystal oscillator input |
| Pin 10 | PB7 / XTAL2 — Port B bit 7 or crystal oscillator output |
| Pin 11 | PD5 — Port D bit 5 / OC0B |
| Pin 12 | PD6 — Port D bit 6 / AIN0 analog comparator positive input |
| Pin 13 | PD7 — Port D bit 7 / AIN1 analog comparator negative input |
| Pin 14 | PB0 — Port B bit 0 / ICP1 input capture |
| Pin 15 | PB1 — Port B bit 1 / OC1A |
| Pin 16 | PB2 — Port B bit 2 / OC1B / SS |
| Pin 17 | PB3 / MOSI — Port B bit 3, SPI master output / ICSP data |
| Pin 18 | PB4 / MISO — Port B bit 4, SPI master input / ICSP data |
| Pin 19 | PB5 / SCK — Port B bit 5, SPI clock / ICSP clock |
| Pin 20 | AVCC — ADC supply voltage |
| Pin 21 | AREF — ADC analog reference input |
| Pin 22 | GND — Analog ground |
| Pin 23 | PC0 / ADC0 — Port C bit 0, ADC channel 0 |
| Pin 24 | PC1 / ADC1 — Port C bit 1, ADC channel 1 |
| Pin 25 | PC2 / ADC2 — Port C bit 2, ADC channel 2 |
| Pin 26 | PC3 / ADC3 — Port C bit 3, ADC channel 3 |
| Pin 27 | PC4 / ADC4 / SDA — Port C bit 4, ADC channel 4 / TWI data |
| Pin 28 | PC5 / ADC5 / SCL — Port C bit 5, ADC channel 5 / TWI clock |
| Pin 29 | PC6 / RESET* — Additional port C pin (per 27-GPIO PB pinout) - verify against datasheet pinout chapter |
| Pin 30 | PD0* — Additional port D pin (per 27-GPIO PB pinout) - verify against datasheet pinout chapter |
| Pin 31 | PD1* — Additional port D pin (per 27-GPIO PB pinout) - verify against datasheet pinout chapter |
| Pin 32 | PD2* — Additional port D pin (per 27-GPIO PB pinout) - verify against datasheet pinout chapter |
Typical Applications
ATMEGA48PB-AN is suitable for 6 applications: Industrial Sensor Nodes, Lighting and HVAC Control, Consumer Appliance Control, Functional-Safety Oriented Designs, Battery-Powered Portable Devices, IoT Sensor Endpoints.
Industrial Sensor Nodes
The ATMEGA48PB-AN fits industrial sensor nodes where low cost, -40C to +105C operation, and low standby current dominate the selection. Its picoPower technology provides microamp-level power-down currents, letting battery-powered nodes sleep between 10-bit ADC conversions of pressure, temperature, or proximity inputs. The 27 GPIO lines drive status LEDs and relay interfaces while the USART forwards readings to a gateway. Because the 20 MHz AVR core executes most instructions in a single cycle, sensor filtering and thresholding complete within microseconds of each conversion. Designers should place a 0.1 uF decoupling capacitor at each supply pin and use the power-save sleep mode with a timer-based wake-up to minimize average current in duty-cycled acquisition loops.
Recommended
Lighting and HVAC Control
In lighting ballasts, dimmers, and HVAC controllers, the ATMEGA48PB-AN's three flexible timer/counters with compare modes generate PWM outputs for brightness and fan-speed control directly in hardware, offloading the CPU. The 105C temperature rating suits enclosed fixtures and control cabinets where ambient heat is significant, and the 2.5V-5.5V supply range tolerates regulated-rail variation. TWI (I2C) reads temperature sensors and EEPROM-stored configuration, while the 10-bit ADC samples potentiometers or NTC thermistors for closed-loop dimming. The 4 KB Flash is sufficient for state machines, soft-start ramps, and fault detection logic. Pin-compatible ATMEGA88PB/168PB upgrades allow a control-feature roadmap without PCB respin, protecting the investment in the same 32-TQFP layout.
Recommended
Consumer Appliance Control
Cost-driven appliance boards - coffee makers, fans, small pumps, and control knobs - benefit from the ATMEGA48PB-AN's sub-$1 unit price (about $0.52 at LCSC as of 2026-09-18) and single-chip integration of timers, ADC, and USART. The 32 general-purpose working registers plus Harvard RISC core give responsive button-scanning and encoder handling even at reduced clock speeds, saving power. TWI interfaces touch controllers or display drivers, while the USART with wake-up-on-start-of-transmission supports isolated communication modules that only wake the MCU when traffic arrives. The GREEN, RoHS-compliant TQFP-32 tray packaging supports high-volume lead-free SMT assembly. Firmware modularity within 4 KB is the main constraint; plan a migration path to pin-compatible ATMEGA88PB/168PB parts if features expand.
Recommended
Functional-Safety Oriented Designs
Microchip offers the ATmega48PB with Functional Safety (FuSa) support documentation, making the ATMEGA48PB-AN a candidate for safety-relevant industrial controls where diagnostic coverage, failure-mode documentation, and development-tool qualification evidence are required. The deterministic single-cycle-per-instruction AVR core simplifies worst-case execution-time analysis, a prerequisite for watchdog-based safety concepts. Three timer/counters support independent time-base cross-checks, and the 10-bit ADC enables redundant measurement of critical analog channels with plausibility checks in the 4 KB firmware. The -40C to +105C rating covers demanding cabinets and outdoor enclosures. Designers should implement core self-tests, use the brown-out detector, and follow the Microchip FuSa package documentation when certifying the end product under applicable safety standards.
Recommended
Battery-Powered Portable Devices
Handheld meters, remote controls, and portable instruments exploit the ATMEGA48PB-AN's picoPower sleep modes to achieve long battery life. In power-down mode, current consumption drops to microamp levels, and the asynchronous timer or pin-change interrupts wake the device for user input or periodic measurement. The 1.8V (reduced-speed) to 5.5V supply range allows direct operation from a lithium coin cell through a simple regulator or even two-cell alkaline stacks. The 10-bit ADC with internal reference digitizes battery-voltage monitoring for low-battery alerts, and TWI drives small OLED or segment LCD controllers. Because wake-up latency is only a few clock cycles, the MCU can spend over 99% of its lifetime asleep in typical duty-cycled instruments, extending coin-cell life to years.
Recommended
IoT Sensor Endpoints
As the endpoint MCU in IoT nodes, the ATMEGA48PB-AN handles local signal conditioning while delegating connectivity to a wireless module over USART or SPI. The USART's wake-on-start-of-transmission feature lets the radio wake the sleeping MCU only when downlink data arrives, and the byte-oriented TWI bus reads humidity, temperature, or light sensors. With 27 GPIO lines, the MCU drives relays or open-collector outputs for actuation in smart plugs and valve controllers. The 4 KB Flash accommodates sensor drivers, a lightweight protocol parser, and OTA-triggered application logic when paired with a module holding the network stack. Designers should budget decoupling on the RF module's supply rail separately from the MCU's 2.5V-5.5V rail to keep ADC readings free of transmit-burst noise.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA48PB-AN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA48PB-AU | ATMEGA48PA-AU | ATMEGA88PB-AU | ATMEGA168PB-AU |
|---|---|---|---|---|---|
| Package | 32-TQFP (7x7 mm) | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - same | 32-TQFP (7x7 mm) - 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 B | 512 B | 512 B | 1 KB | 1 KB |
| EEPROM | 256 B | 256 B | 256 B | 512 B | 512 B |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Temperature | -40C to +105C | -40C to +105C | -40C to +85C | -40C to +105C | -40C to +105C |
| PicoPower Technology | Yes | Yes | Yes | Yes | Yes |
| Pin 3 / Pin 6 Migration Caution | N/A (PB silicon) | N/A (PB silicon) | Conditions apply (AppNote 00002602A) | N/A (PB silicon) | N/A (PB silicon) |
| Packing | Tray | Tray | Tray | Tray | Tray |
Key Differentiators
- Latest PB silicon generation (vs ATMEGA48PA-AU)
- Lowest cost within the PB TQFP family (vs ATMEGA168PB-AU)
- Extended temperature with picoPower (vs ATMEGA48A (non-P generation))
Design Notes
Connect AVCC (pin 20) to VCC through a low-pass RC filter (e.g., 10 ohm series resistor plus 0.1 uF capacitor) when ADC accuracy matters, and keep the analog ground pin 22 star-connected to the digital ground. Decouple VCC with a 0.1 uF ceramic capacitor placed within 5 mm of pin 7. Estimated: at 20 MHz and 5V, active current is on the order of 10-15 mA per typical AVR figures, so an RC filter dropping a few hundred millivolts is acceptable; verify against the datasheet current-consumption tables for your exact clock configuration.
If migrating an existing ATmega48PA PCB to the ATMEGA48PB, review Microchip application note 00002602A before release: pin 3 must not be actively driven if it is connected to GND and the analog comparator output (ACO) must not be enabled; pin 6 must not be actively driven if connected to VCC. Schematics that ground or tie these pins to rails may function incorrectly on PB silicon. Also confirm fuse settings (clock source, brown-out threshold) after reprogramming, since PB and PA devices share the same ISP interface but should be regression-tested.
For the 32-pin TQFP 7x7 mm footprint, use a continuous ground plane under the package and route the crystal traces (PB6/XTAL1, PB7/XTAL2) as short as possible with guard ground. Keep the RESET line (pin 1) pulled up 10 kohm to VCC with an optional 0.1 uF to ground for robust ICSP programming with MPLAB Snap. Reserve test points on MOSI/MISO/SCK/RESET to allow in-field reprogramming, and leave the footprint compatible with ATMEGA88PB/168PB upgrades for a no-respin code-size migration path.
Compliance Information
Mouser listing identifies the part as GREEN, which in Microchip nomenclature denotes RoHS-compliant lead-free construction. REACH, halogen-free, and conflict-minerals status should be confirmed from current Microchip material declarations.
