ATMEGA48A-PU - 8-bit AVR MCU 4KB Flash 20MHz DIP-28 | Microchip
料号： ATMEGA48A-PU ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.05 | $1.05 |
| 10 | $0.96 | $9.60 |
| 100 | $0.89 | $89.00 |
| 500 | $0.84 | $420.00 |
| 1,000 | $0.78 | $780.00 |
ATMEGA48A-PU 概述
A microcontroller (MCU) is a single-chip computer that integrates a processor core, program memory, data memory, and peripheral functions such as timers, serial interfaces, and ADCs. MCUs sit at the lowest level of the embedded-systems hierarchy, controlling a single dedicated function within a larger electronic system, and the 8-bit AVR family is one of the most widely used MCU architectures for cost-sensitive, low-complexity control tasks.
The ATmega48A implements the advanced AVR RISC architecture with 131 powerful instructions, most executing in a single clock cycle, giving up to 20 MIPS throughput at 20MHz. On-chip peripherals include two 8-bit timer/counters, one 16-bit timer with compare modes, a 10-bit 6-channel ADC, USART, SPI, and I2C-compatible two-wire interface. The device also offers a programmable watchdog timer, internal calibrated RC oscillator, and six sleep modes for low-power designs.
The AVR core uses a Harvard architecture with separate program and data buses and 32 general-purpose working registers directly connected to the ALU, allowing single-cycle access that eliminates the bottleneck of the classic accumulator architecture. In-system programmable (ISP) Flash enables firmware updates on the assembled PCB through SPI without removal of the device.
Typical applications include hobbyist and educational projects such as Arduino-style boards, small industrial sensors and actuators, home appliances, battery chargers, and motor control circuits. The 28-pin DIP package makes it especially popular for breadboard prototyping, through-hole production runs, and repair/retrofit of legacy designs.
Design consideration: full 20MHz speed and flash self-programming are guaranteed only at 4.5V to 5.5V; at lower voltages the maximum clock frequency derates significantly, so check the frequency-versus-voltage curve before combining a 3.3V rail with a high crystal frequency.
This page synthesizes distributor pricing, pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single citable reference for the ATMEGA48A-PU.
直接替换替代料： ATMEGA48A-PU ——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： ATMEGA48A-PU （相同外形与封装尺寸） ——差异在于 Package, Operating Temperature, EEPROM, SRAM, Timers.
快速对比工具——选择替代料号进行并排对比：
ATMEGA48-20PI
✅ 直接替换✓ 有现货
$0.98 / 个
查看数据手册 →ATMEGA88-PU
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA168-PU
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA328P-PU
✅ 直接替换✓ 有现货
联系询价
查看数据手册 →ATMEGA328-PU
✅ 直接替换📋 参考替代料（不在目录中）
ATMEGA48A-PU 最大额定值与电气特性
| Core | AVR 8-bit RISC |
| Core Size | 8-bit |
| Speed | 20 MHz |
| Flash Memory | 4 KB (2K x 16) |
| EEPROM | 256 B |
| SRAM | 512 B |
| 电源电压 | 4.5 V to 5.5 V |
| I/O Count | 23 |
| Timers | 2 x 8-bit, 1 x 16-bit |
| ADC | 10-bit, 6 channels |
| Serial Interfaces | USART, SPI, I2C (TWI) |
| 工作温度 | -40C to +85C |
| 封装 | 28-PDIP (through-hole) |
| 安装类型 | Through Hole |
| Life Cycle Stage | ACTIVE |
| ISP Capability | In-System Programmable Flash |
| Sleep Modes | 6 modes |
ATMEGA48A-PU 引脚配置
| 引脚 1 | PC6/RESET — Port C bit 6 or active-low reset input (also debugWIRE pin) |
| 引脚 2 | PD0/RX — Port D bit 0, USART receive input |
| 引脚 3 | PD1/TX — Port D bit 1, USART transmit output |
| 引脚 4 | PD2/INT0 — Port D bit 2, external interrupt 0 |
| 引脚 5 | PD3/INT1 — Port D bit 3, external interrupt 1 |
| 引脚 6 | PD4/T0 — Port D bit 4, timer/counter 0 external input |
| 引脚 7 | VCC — Digital supply voltage (4.5 V to 5.5 V for full speed) |
| 引脚 8 | GND — Ground |
| 引脚 9 | PB6/XTAL1 — Port B bit 6 or crystal oscillator input |
| 引脚 10 | PB7/XTAL2 — Port B bit 7 or crystal oscillator output |
| 引脚 11 | PD5/T1 — Port D bit 5, timer/counter 1 external input |
| 引脚 12 | PD6/AIN0 — Port D bit 6, analog comparator positive input |
| 引脚 13 | PD7/AIN1 — Port D bit 7, analog comparator negative input |
| 引脚 14 | PB0/ICP1 — Port B bit 0, timer/counter 1 input capture |
| 引脚 15 | PB1/OC1A — Port B bit 1, timer/counter 1 output compare A (PWM) |
| 引脚 16 | PB2/OC1B — Port B bit 2, timer/counter 1 output compare B (PWM) |
| 引脚 17 | PB3/MOSI/OC2A — Port B bit 3, SPI master output / ISP data in / Timer2 PWM |
| 引脚 18 | PB4/MISO — Port B bit 4, SPI master input / ISP data out |
| 引脚 19 | PB5/SCK — Port B bit 5, SPI clock / ISP programming clock |
| 引脚 20 | AVCC — ADC supply voltage, connect to VCC via low-pass filter |
| 引脚 21 | AREF — ADC analog reference voltage |
| 引脚 22 | GND — Ground |
| 引脚 23 | PC0/ADC0 — Port C bit 0, ADC channel 0 |
| 引脚 24 | PC1/ADC1 — Port C bit 1, ADC channel 1 |
| 引脚 25 | PC2/ADC2 — Port C bit 2, ADC channel 2 |
| 引脚 26 | PC3/ADC3 — Port C bit 3, ADC channel 3 |
| 引脚 27 | PC4/ADC4/SDA — Port C bit 4, ADC channel 4 / I2C data line |
| 引脚 28 | PC5/ADC5/SCL — Port C bit 5, ADC channel 5 / I2C clock line |
典型应用
ATMEGA48A-PU 适用于 6 应用s: Arduino-Style Hobbyist and Educational Boards, Small Industrial Sensors and Actuators, Home Appliance Control, Battery Chargers and Power Management, DC and Stepper Motor Control, Legacy Repair, Retrofit, and Through-Hole Production.
Arduino-Style Hobbyist and Educational Boards
The ATMEGA48A-PU fits hobbyist and educational embedded projects because its 28-pin PDIP package plugs directly into breadboards and DIP sockets, and its 20MHz AVR core with 131 single-cycle instructions is approachable for learners. With 4KB Flash and 512B SRAM it hosts compact bare-metal C/assembly programs, SPI/USART demos, and simple sensor readouts using the 10-bit ADC. Its ISP programming over PB3/PB4/PB5 plus RESET allows programming with inexpensive USBasp tools, so no debugger investment is required. For projects needing Arduino bootloaders and library ecosystems, the pin-compatible ATMEGA328P-PU in the same socket is the recommended upgrade, keeping the PCB unchanged.
推荐
Small Industrial Sensors and Actuators
In industrial sensing nodes, the ATMEGA48A-PU provides a cost-optimized control core: its 10-bit 6-channel ADC digitizes analog transducer signals, the USART links to RS-485/RS-232 transceivers, and the TWI (I2C) interface reads external EEPROMs or digital sensors at 5V levels that tolerate electrically noisy industrial environments. Operating from -40C to +85C and rated at 4.5V to 5.5V, it runs directly from industrial 5V rails without level shifting. The watchdog timer provides autonomous fault recovery in unattended installations. Use the Power-down sleep mode between acquisition cycles to cut average consumption in battery-backed field nodes.
推荐
Home Appliance Control
White goods and small appliance controllers benefit from the ATMEGA48A-PU's combination of three timer/counters (two 8-bit, one 16-bit with compare modes), 23 GPIO lines, and internal calibrated oscillator. The 16-bit timer generates precise PWM for heater or motor phase control, while button interfaces and LED indicators map naturally onto the remaining port pins. In-system programmable Flash lets manufacturers update firmware on assembled boards during final test or field service without desoldering the device. Running the internal 8MHz RC oscillator removes the crystal and its cost, and the six sleep modes support standby power compliance targets.
推荐
Battery Chargers and Power Management
Smart battery charger supervisory circuits use the ATMEGA48A-PU's 10-bit ADC to monitor cell voltage and current via shunt sensing, and its 8-bit timers to generate charging PWM with adjustable duty cycle. The programmable watchdog plus brown-out detection provides safe behavior under supply anomalies, and the 256B EEPROM stores charge-profile parameters and cycle counters across power cycles. Because full 20MHz speed requires 4.5V to 5.5V, designs using a single-cell lithium rail should clock the part from the internal RC oscillator at lower frequency, or regulate a clean 5V domain for the MCU while power electronics run elsewhere on the board.
推荐
DC and Stepper Motor Control
The ATMEGA48A-PU drives small DC and stepper motors using its 16-bit timer's compare channels for PWM generation and the 8-bit timers for tachometer input capture or quadrature decoding in software. At 20MHz the core delivers 20 MIPS, sufficient for closed-loop speed control of hobby-class motors with PI loops executed in fixed-point math within 512B SRAM. High-side/low-side drive stages are commanded through GPIO and PWM pins into MOSFET gate drivers. Note that at large PWM loads the ADC ground reference should be taken from a star ground near AVCC (pin 20) to keep 10-bit conversions free of motor-switching noise.
推荐
Legacy Repair, Retrofit, and Through-Hole Production
For repairing or remanufacturing legacy equipment that used DIP-packaged AVR or PIC MCUs, the ATMEGA48A-PU's through-hole 28-PDIP format allows direct socket insertion without adapters. Its 4KB Flash accommodates replacement firmware reimplementing classic controller logic, and the ATmega48/88/168/328 pin compatibility lets a service shop stock one socket-compatible family with four memory grades, swapping the ATMEGA328P-PU when larger programs are needed. In low-volume through-hole production where wave soldering is retained, the DIP package avoids the reflow profiling and moisture-sensitivity handling that QFP/SMD MCU packages require, simplifying mixed-technology assembly.
推荐
推荐产品汇总
工程参考数据： ATMEGA48A-PU ——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 | ATMEGA48-20PI | ATMEGA88-PU | ATMEGA168-PU | ATMEGA328P-PU |
|---|---|---|---|---|---|
| Package | 28-PDIP (through-hole) | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 4 KB | 4 KB | 8 KB | 16 KB | 32 KB |
| SRAM | 512 B | 512 B | 1 KB | 1 KB | 2 KB |
| EEPROM | 256 B | 256 B | 512 B | 512 B | 1 KB |
| Max Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| I/O Lines | 23 | 23 | 23 | 23 | 23 |
| Low-Power Technology | Standard (ATmega48A revision) | Standard (original ATmega48) | Standard | Standard / picoPower (168PA) | picoPower |
关键差异点
- Lowest cost in the pin-compatible ATmega DIP-28 family （对比 ATMEGA328P-PU)
- Newer 'A' silicon revision with improved power figures （对比 ATMEGA48-20PI)
- Through-hole PDIP format unique among memory grades （对比 ATMEGA48A-MU)
设计说明
The ATMEGA48A-PU guarantees 20MHz full-speed operation only from 4.5V to 5.5V. Below 4.5V the maximum safe clock frequency derates per the datasheet frequency-versus-voltage curve (roughly 4MHz at 2.5V). Run the internal calibrated 8MHz RC oscillator at 3.3V or 2.5V rails, and disable the brown-out detector or re-select its threshold in fuses to match the lower rail. Estimated: at 5V and 20MHz with capacitive loads on all 23 I/O lines, dynamic current dominates active consumption, so keep unloaded pins as inputs with pull-ups or outputs low to minimize wasted drive current.
Decouple VCC (pin 7) and AVCC (pin 20) each with a 100nF ceramic capacitor placed within a few millimeters of the pins, plus a bulk 10uF per power domain. AVCC should be connected to VCC through a low-pass filter (e.g., 10 ohm resistor plus 100nF) when the ADC is used, and AREF (pin 21) needs its own 100nF capacitor to GND - never hang a large capacitor directly on AREF when using the internal reference. Keep the analog ground return for pin 22 separate from digital ground until a single star point. Provide a standard 6-pin ISP header (VCC, GND, RESET, MOSI, MISO, SCK) for in-system programming.
Three frequent mistakes with this device: (1) leaving RESET (pin 1) floating - fit a 10k pull-up to VCC; debugWIRE shares this pin and can be accidentally enabled by the DWEN fuse, requiring a high-voltage parallel programmer to recover. (2) Migrating firmware between ATmega48/88/168/328 without re-checking fuse bytes - signature and fuse layouts differ between family generations, so always read the target signature before ISP programming. (3) Exceeding 20MHz below 4.5V, which violates the speed grade and causes erratic execution. Verify clock source fuses (internal RC vs external crystal on PB6/PB7) before first power-up of a new board.
合规信息
RoHS/lead-free status per LCSC product page (C1337386) for current production lots; REACH and conflict-minerals declarations not present in provided data - obtain from Microchip compliance portal. Life cycle stage listed as ACTIVE per chipdig data.
