ATMEGA48-20MI - 8-bit AVR MCU 20MHz 4KB Flash VQFN-32 | Microchip
料号： ATMEGA48-20MI ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATMEGA48-20MI 概述
An 8-bit AVR microcontroller is a single-chip processor that executes an advanced RISC instruction set (131 instructions, most in a single clock cycle) and integrates program Flash, data SRAM, EEPROM, timers, analog peripherals and I/O on one die. Within the power-management hierarchy, MCUs like the ATmega48 sit at the node level, reading sensors and driving actuators in embedded systems ranging from consumer appliances to industrial control.
Key features include 23 general-purpose I/O lines, three flexible timer/counters with compare modes, an 8-channel 10-bit ADC, and debugWIRE on-chip debugging that uses only the reset line. The picoPower technology supports multiple sleep modes for battery-operated designs, and operation spans 1.8 V to 5.5 V at full 20 MHz speed grade.
Architecturally, the AVR uses a Harvard structure with 32 general-purpose working registers directly connected to the ALU, allowing two independent instructions to execute in one cycle. Self-programming Flash enables in-system programming (ISP) and bootloader firmware updates in the field, while the 32-pin QFN footprint with exposed pad improves thermal and ground performance on compact two-layer PCBs.
Typical applications include sensor nodes and battery-powered IoT devices (leveraging low-voltage 1.8 V operation and sleep modes), small motor and LED control boards using the three timers, and industrial consumer appliances where debugWIRE simplifies in-circuit development without a JTAG pod.
When designing, remember the industrial temperature range (-40 C to +85 C) applies to the MI suffix, and Brown-out detection plus the internal 8 MHz RC oscillator eliminate external components at moderate clock rates; reserve the crystal option for UART-heavy or timing-critical designs.
This page synthesizes distributor stock data, drop-in same-family alternatives, pinout detail, and practical design notes not consolidated in the manufacturer datasheet, with pricing freshness noted as of 2026-09-18.
直接替换替代料： ATMEGA48-20MI ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ATMEGA48-20MI （相同外形与封装尺寸） ——差异在于 Package, EEPROM, SRAM, ADC, Flash Memory.
快速对比工具——选择替代料号进行并排对比：
ATMEGA48-20MU
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA48A-MU
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA48PA-MU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$1.08 / 个
查看数据手册 →ATMEGA88-20MU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
联系询价
查看数据手册 →ATMEGA168-20MU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
联系询价
查看数据手册 →ATMEGA328P-MU
✅ 直接替换✓ 有现货
$2.85 / 个
查看数据手册 →ATMEGA48V-10MU
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$2.38 / 个
查看数据手册 →ATMEGA48-20MI 最大额定值与电气特性
| Core | AVR 8-bit RISC |
| Core Size | 8-bit |
| Max Clock Frequency | 20 MHz |
| Throughput | Up to 20 MIPS at 20 MHz |
| Flash Memory | 4 KB (2K x 16) In-System Programmable |
| SRAM | 512 B |
| EEPROM | 256 B |
| Operating Voltage Range | 1.8 V to 5.5 V |
| I/O Count | 23 general purpose I/O lines |
| Timers | 3 timer/counters with compare modes |
| ADC | 8-channel 10-bit |
| On-Chip Debug | debugWIRE |
| Working Registers | 32 x 8-bit general purpose |
| Instruction Set | 131 instructions, mostly single-cycle |
| 工作温度 | -40 C to +85 C (industrial) |
| 封装 | 32-VQFN (5x5 mm) exposed pad |
| 安装类型 | Surface Mount |
| Technology | picoPower low power |
| Series | AVR ATmega |
ATMEGA48-20MI 引脚配置
| 引脚 1 | PD3 — Port D, bit 3 (GPIO / INT1) |
| 引脚 2 | PD4 — Port D, bit 4 (GPIO / XCK/T0) |
| 引脚 3 | GND — Ground |
| 引脚 4 | VCC — Digital supply voltage |
| 引脚 5 | GND — Ground |
| 引脚 6 | VCC — Digital supply voltage |
| 引脚 7 | PB6 — Port B, bit 6 (XTAL1/TOSC1) |
| 引脚 8 | PB7 — Port B, bit 7 (XTAL2/TOSC2) |
| 引脚 9 | PD5 — Port D, bit 5 (GPIO / T1) |
| 引脚 10 | PD6 — Port D, bit 6 (GPIO / AIN0) |
| 引脚 11 | PD7 — Port D, bit 7 (GPIO / AIN1) |
| 引脚 12 | PB0 — Port B, bit 0 (GPIO / ICP1/OC0A) |
| 引脚 13 | PB1 — Port B, bit 1 (GPIO / OC1A) |
| 引脚 14 | PB2 — Port B, bit 2 (GPIO / SS/OC1B) |
| 引脚 15 | PB3 — Port B, bit 3 (GPIO / MOSI/OC2A) |
| 引脚 16 | PB4 — Port B, bit 4 (GPIO / MISO) |
| 引脚 17 | PB5 — Port B, bit 5 (GPIO / SCK) |
| 引脚 18 | AVCC — ADC supply voltage |
| 引脚 19 | ADC6 — ADC input channel 6 |
| 引脚 20 | AREF — Analog reference voltage |
| 引脚 21 | GND — Ground |
| 引脚 22 | ADC7 — ADC input channel 7 |
| 引脚 23 | PC0 — Port C, bit 0 (GPIO / ADC0) |
| 引脚 24 | PC1 — Port C, bit 1 (GPIO / ADC1) |
| 引脚 25 | PC2 — Port C, bit 2 (GPIO / ADC2) |
| 引脚 26 | PC3 — Port C, bit 3 (GPIO / ADC3) |
| 引脚 27 | PC4 — Port C, bit 4 (GPIO / ADC4/SDA) |
| 引脚 28 | PC5 — Port C, bit 5 (GPIO / ADC5/SCL) |
| 引脚 29 | PC6 — Port C, bit 6 (RESET / debugWIRE) |
| 引脚 30 | PD0 — Port D, bit 0 (GPIO / RXD) |
| 引脚 31 | PD1 — Port D, bit 1 (GPIO / TXD) |
| 引脚 32 | PD2 — Port D, bit 2 (GPIO / INT0) |
典型应用
ATMEGA48-20MI 适用于 6 应用s: Battery-Powered Sensor Nodes, Small Motor and Fan Control, LED Lighting and Dimming Control, Consumer Appliance Control Panels, Industrial Sensing and 4-20 mA Transmitters, Hobby, Education and Rapid Prototyping.
Battery-Powered Sensor Nodes
The ATMEGA48-20MI suits battery-powered sensor nodes because its picoPower technology provides multiple sleep modes and it operates from 1.8 V, allowing direct use of a two-cell alkaline supply without a boost converter. A typical node places the MCU in power-down between measurement intervals, waking on pin-change or watchdog interrupt to read a thermistor via the 8-channel 10-bit ADC and transmit over a simple UART or RF link. Using the internal 8 MHz RC oscillator eliminates the crystal and its associated quiescent load, reducing component count on cost-optimized nodes. The 4 KB Flash is generally sufficient for protocol-and-measure firmware; if OTA update payloads grow, the pin-compatible ATMEGA328P-MU allows a memory upgrade without PCB change.
推荐
Small Motor and Fan Control
Three flexible timer/counters with compare and PWM modes make the ATMEGA48-20MI an economical controller for small DC or brushless fan/motor boards. One timer generates the PWM carrier (e.g., 20 kHz to stay above audible range) while a second counts encoder or tacho pulses for closed-loop speed regulation, and the 10-bit ADC samples a back-EMF or current-sense voltage for stall detection. Running from a 5 V rail at 20 MHz provides ample MIPS for a PI loop at kHz rates. The 32-VQFN exposed-pad package provides a solid ground reference for switching noise; decouple AVCC separately and keep the motor-driver gate traces away from the ADC reference to preserve conversion accuracy.
推荐
LED Lighting and Dimming Control
In LED luminaires and dimmable fixtures, the ATMEGA48-20MI generates hardware PWM on multiple channels simultaneously using its three timers, supporting color mixing or multi-zone dimming without CPU-intensive software timing. The 10-bit ADC can read a potentiometer, 0-10 V analog dimming input, or NTC temperature sensor mounted on the LED heatsink, enabling thermal foldback that extends LED lifetime. Operation from 1.8 V to 5.5 V allows direct integration with low-voltage control rails. Because hardware PWM continues during CPU sleep, the firmware can park in idle mode between dimming-level changes, trimming standby consumption; the 4 KB Flash accommodates typical dimming-curve and communication firmware with room to spare.
推荐
Consumer Appliance Control Panels
Washing machines, small HVAC controllers, and kitchen appliances commonly use ATmega-class MCUs for keypad scanning, display driving, and relay control. The ATMEGA48-20MI's 23 GPIO lines cover a 4x4 keypad plus segment or LED-matrix display in one package, and its industrial temperature rating (-40 C to +85 C) covers unventilated appliance enclosures. debugWIRE on-chip debugging through the RESET line lets developers instrument code on the actual production board without sacrificing I/O for a debug header. The 256 B EEPROM stores cycle counters and user presets across power cycles. Brown-out detection ensures predictable reset behavior during mains dips, a frequent occurrence in appliance environments.
推荐
Industrial Sensing and 4-20 mA Transmitters
The ATMEGA48-20MI's 10-bit ADC with selectable internal bandgap reference makes it viable for industrial loop-powered transmitters, where it digitizes a sensor (RTD, strain bridge, or pressure element) and drives a PWM-filtered or DAC-based 4-20 mA output stage. Running from a 3.3 V or 5 V loop-derived supply within its 1.8-5.5 V range simplifies power extraction from the current loop. The industrial -40 C to +85 C rating matches field-mounted transmitter enclosures. Because loop budget is limited, choose the ATMEGA48PA variant for lower active current, and place the ADC in noise-reduction mode during conversions to lower sample noise on millivolt-level bridge signals.
推荐
Hobby, Education and Rapid Prototyping
The ATmega48 family is fully supported by open toolchains (avr-gcc, Microchip Studio, and the MiniCore Arduino hardware package), making the ATMEGA48-20MI a favorite for prototypes, student projects, and maker products. Its 4 KB Flash and 512 B SRAM force disciplined C code, which is an excellent teaching constraint, while debugWIRE single-wire debugging works with low-cost programmers. When a prototype outgrows the memory, moving to the pin-compatible ATMEGA88, ATMEGA168, or ATMEGA328P on the same QFN-32 footprint requires no layout change - a property unique to this AVR family ladder. Distributor stock and same-day shipping keep prototype iterations fast.
推荐
推荐产品汇总
工程参考数据： ATMEGA48-20MI ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ATMEGA48-20MU | ATMEGA48PA-MU | ATMEGA88-20MU | ATMEGA328P-MU |
|---|---|---|---|---|---|
| Package | 32-VQFN (5x5 mm) exposed pad | 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 |
| Flash Memory | 4 KB | 4 KB | 4 KB | 8 KB | 32 KB |
| SRAM | 512 B | 512 B | 512 B | 1 KB | 2 KB |
| EEPROM | 256 B | 256 B | 256 B | 512 B | 1 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 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 |
| ADC | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit |
| Power Optimization | picoPower family | Standard ATmega48 die | picoPower-optimized (lower sleep current) | Standard | picoPower (P-series) |
| On-Chip Debug | debugWIRE | debugWIRE | debugWIRE | debugWIRE | debugWIRE |
关键差异点
- Lowest Flash/RAM in a pin-compatible upgrade ladder （对比 ATMEGA328P-MU)
- Standard ATmega48 die cost vs picoPower refresh （对比 ATMEGA48PA-MU)
- Full 20 MHz speed grade （对比 ATMEGA48V-10MU)
设计说明
The 32-VQFN package has two VCC pins (4 and 6) plus a separate AVCC pin (18). Connect both VCC pins to the same 5 V (or 3.3 V) rail and never leave either floating; AVCC must be tied to VCC through an LC filter (e.g., 10 uH inductor with 100 nF) when ADC accuracy matters, and must never exceed VCC by more than 0.3 V or the ADC and digital logic can be damaged. Enable the internal brown-out detector at approximately 2.7 V for 5 V systems to guarantee predictable resets during supply dips.
The exposed pad on the underside of the QFN-32 is internally connected to GND and must be soldered to a grounded copper pour with an array of thermal vias - relying on perimeter leads alone gives an unreliable connection and poor ground integrity. Place 100 nF ceramic decoupling capacitors within 2 mm of each VCC pin and an additional 100 nF close to AVCC. AREF needs a 100 nF capacitor to ground when the internal reference is used; add an external reference source there only if ADC ratiometric accuracy to VCC is not required.
The debugWIRE interface shares the RESET pin (PC6, pin 29) with high-voltage programming; once the DWEN fuse is set, normal ISP programming and external reset behavior are disabled until debugWIRE is disabled from the debugger, a step beginners often miss and conclude the chip is dead. Also note RESET is active-low with an internal pull-up - if your circuit drives it, keep the driver open-drain. Clock-source fuses determine whether PB6/PB7 act as XTAL pins or GPIO; changing clock fuses incorrectly can lock out the device, so set them deliberately.
When using the internal 8 MHz RC oscillator, keep digital I/O switching currents (LED matrix, relays) physically separated from the XTAL-free PB6/PB7 area used as GPIO, and route ADC input traces short and away from UART/PWM lines. For crystal operation above 16 MHz, follow the datasheet's load-capacitor guidance (typically 12-22 pF depending on crystal) and place the crystal within 5 mm of pins 7-8 with a ground guard ring to prevent stray coupling from causing startup failures.
合规信息
The ATmega48 is offered in Microchip's green (halogen-free/lead-free) package variants per family practice, but explicit RoHS/REACH statements for this exact ordering code were not present in the verified web data and should be confirmed from the Microchip product page certificate documents.
