ATMEGA325PA-MUR - 8-bit AVR MCU 32KB 20MHz 64-QFN | Microchip
料号： ATMEGA325PA-MUR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $2.23 | $2.23 |
| 10 | $2.06 | $20.60 |
| 100 | $1.91 | $191.00 |
| 500 | $1.78 | $890.00 |
| 1,000 | $1.65 | $1,650.00 |
ATMEGA325PA-MUR 概述
An 8-bit microcontroller integrates a processor core, memory, and peripherals on a single chip, forming the lowest tier of the embedded-processor hierarchy (MCU -> embedded processor -> semiconductor). AVR is a modified Harvard architecture with mostly single-cycle instruction execution, making it a popular alternative to PIC16-class and 8051-class MCUs for cost-sensitive embedded control.
Key features include picoPower technology for ultra-low active and sleep current, an 8-channel 10-bit ADC, a JTAG interface for on-chip debugging and boundary scan, and wide 1.8V to 5.5V single-supply operation. The 131-instruction AVR core executes most instructions in a single clock cycle, and 32 general-purpose working registers keep interrupt latency low.
Architecturally, the self-programming Flash allows in-system firmware updates via boot-loader code, while the separate EEPROM retains calibration data through power cycles. Advanced power-management modes (idle, power-save, power-down, standby) let designers trade wake-up latency against microamp-level sleep current, a hallmark of the picoPower A-series silicon.
Typical applications include industrial sensor nodes, consumer appliance control panels, battery-powered metering, and HVAC/LCD user interfaces where a rich I/O count and ADC channels are required in a compact 9x9 mm footprint.
A key design consideration is supply-voltage-dependent maximum clock speed: at 1.8V the safe operating frequency is derated substantially below 20 MHz, so consult the frequency-versus-voltage curve in the manufacturer datasheet before finalizing the oscillator design.
This page synthesizes distributor pricing, verified drop-in alternatives within the AVR family, and practical design notes not found in the manufacturer datasheet alone.
直接替换替代料： ATMEGA325PA-MUR ——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： ATMEGA325PA-MUR （相同外形与封装尺寸） ——差异在于 Package, RoHS Status, Flash Memory, Operating Temperature, Maximum Clock Frequency.
快速对比工具——选择替代料号进行并排对比：
ATMEGA325P-20MUR
✅ 直接替换✓ 有现货
$2.86 / 个
查看数据手册 →ATMEGA325-16MI
✅ 直接替换✓ 有现货
$3.05 / 个
查看数据手册 →ATMEGA329P-20MUR
✅ 直接替换✓ 有现货
$5.4 / 个
查看数据手册 →ATMEGA3250PA-MUR
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA645P-20MUR
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ATMEGA325PA-MUR 最大额定值与电气特性
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 32 KB (16K x 16) |
| SRAM | 2 KB |
| EEPROM | 1 KB |
| 最大时钟频率 | 20 MHz |
| Peak Throughput | 20 MIPS at 20 MHz |
| Supply Voltage Range | 1.8 V to 5.5 V |
| ADC | 8-channel 10-bit |
| Debug Interface | JTAG (on-chip debug, boundary scan) |
| Low-Power Technology | picoPower |
| 封装 | 64-QFN (MLF) 9x9 mm, exposed pad |
| 安装类型 | Surface Mount |
| Temperature Range | Industrial |
| Instructions | 131 powerful instructions, most single-cycle |
| Packaging / Reeling | Tape & Reel (R suffix), GREEN |
| RoHS 状态 | Compliant (GREEN package) |
ATMEGA325PA-MUR 64-qfn (mlf) 9x9 mm, exposed pad 引脚配置指南
ATMEGA325PA-MUR（64-qfn (mlf) 9x9 mm, exposed pad 封装）的引脚配置。 该数字 IC 包含 GPIO、通信接口（UART、SPI、I2C）和电源引脚。请参阅制造商数据手册以了解复用引脚功能和配置选项。对嵌入式系统设计和 PCB 布局至关重要。
暂无详细引脚数据： ATMEGA325PA-MUR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ATMEGA325PA-MUR 适用于 6 应用s: Industrial Sensor Nodes, Battery-Powered Metering, Appliance Control Panels, HVAC and Building Automation, Portable Instrumentation, Embedded Control Retrofits.
Industrial Sensor Nodes
The ATMEGA325PA-MUR suits industrial sensor nodes because its 8-channel 10-bit ADC digitizes multiple analog sensors (pressure, temperature bridge, potentiometer) without an external converter, while 1.8-5.5 V operation tolerates unregulated 24 V-bus-derived or battery supplies. The picoPower A-series die reduces active-mode current, extending life in duty-cycled nodes that sleep in power-down between samples. Placed as the main controller with SPI/I2C peripherals and JTAG available for field diagnostics, it delivers 20 MIPS headroom for local filtering and protocol handling at 20 MHz; trade-off: 8-bit core limits heavy DSP workloads versus 32-bit alternatives.
推荐
Battery-Powered Metering
For electricity, water, and heat meters, the ATMEGA325PA-MUR combines microamp-class picoPower sleep modes with the 1 KB EEPROM needed to store cumulative register and calibration data through power cycles. The 10-bit ADC samples shunt or CT inputs, and the asynchronous timer keeps an RTC alive in power-save mode. Operating directly from 1.8-5.5 V battery stacks removes a regulator stage, cutting quiescent drain. Firmware self-programming in the 32 KB Flash enables sealed-unit tariff updates over the communication link; the main consideration is scheduling ADC bursts from sleep to keep average consumption within the battery budget.
推荐
Appliance Control Panels
Appliance user interfaces need many I/O for keys, LEDs, and relays - exactly what the 64-pin ATMEGA325PA-MUR provides, with generous port width and the 10-bit ADC for NTC temperature sensing in ovens and refrigerators. Industrial temperature rating and 5 V tolerant operation align with appliance power rails, while the 9x9 mm MLF keeps the controller footprint small on cost-driven single-sided-dense PCBs. The JTAG interface supports production-line boundary-scan testing of board assembly. Use the internal RC oscillator to eliminate a crystal and its cost; reserve the external crystal only where timing accuracy for communications demands it.
推荐
HVAC and Building Automation
In HVAC controllers and damper/valve actuators, the ATMEGA325PA-MUR reads multiple NTC sensors through its 8-channel ADC and drives triacs, relays, and stepper valves from its wide port set. The 1.8-5.5 V range accepts transformer-derived supplies, and picoPower sleep modes cut standby draw in always-plugged equipment where standby legislation applies. At 20 MHz the AVR core comfortably runs PID loops and Modbus/UART communication simultaneously. Designers should budget RC-oscillator tolerance for UART timing or fit a crystal, and use the EEPROM for setpoint persistence across outages - both standard patterns in Microchip's AVR reference designs.
推荐
Portable Instrumentation
Handheld instruments benefit from the ATMEGA325PA-MUR's 1.8 V minimum supply, which runs directly from two NiMH or alkaline cells down to end-of-discharge, and from picoPower power-down mode that preserves battery between measurements. The 10-bit ADC with internal reference handles transducer front ends, while 32 KB Flash accommodates menu systems, calibration tables, and logging firmware. JTAG enables firmware development on the actual handheld board without sockets. Placed with an SPI display and MEMS sensors, the part delivers responsive 20 MIPS interactive performance; the key trade-off is the MLF package's rework difficulty in low-volume prototypes, mitigated by hot-plate assembly.
推荐
Embedded Control Retrofits
Legacy AVR designs based on the ATmega325/3250 non-picoPower generations can be refreshed to the ATMEGA325PA-MUR without PCB changes, gaining lower active and sleep current in the identical 64-QFN footprint and keeping the same AVR Studio toolchain and ISP programming fixtures. This makes it a natural modernization drop for service parts and long-lifecycle industrial equipment. Firmware written for the earlier die runs unchanged in nearly all cases, with only fuse and signature-byte housekeeping required. Engineering effort is limited to a validation run; the payoff is reduced standby power and continued factory support on an active lifecycle status.
推荐
推荐产品汇总
工程参考数据： ATMEGA325PA-MUR ——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 | ATMEGA325P-20MUR | ATMEGA325-16MI | ATMEGA329P-20MUR | ATMEGA645P-20MUR |
|---|---|---|---|---|---|
| Package | 64-QFN (MLF) 9x9 mm | 64-QFN (MLF) 9x9 mm - same | 64-QFN (MLF) - same | 64-QFN (MLF) - same | 64-QFN (MLF) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 32 KB | 32 KB | 32 KB | 32 KB | 64 KB |
| Max Clock | 20 MHz | 20 MHz | 16 MHz | 20 MHz | 20 MHz |
| SRAM | 2 KB | 2 KB | 2 KB | 2 KB | 4 KB |
| Low-Power Technology | picoPower (A-series) | picoPower (P die) | No (standard) | picoPower (P die) | picoPower (P die) |
| LCD Driver | No | No | No | Yes (segment LCD) | Yes (segment LCD) |
| Supply Voltage | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 2.7 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Lifecycle Status | Active | Active | Active | Active | Active |
关键差异点
- picoPower A-series die lowers sleep current （对比 ATMEGA325P-20MUR)
- Full 1.8-5.5 V operation at 20 MHz rating （对比 ATMEGA325-16MI)
- Maximum general-purpose I/O in the family footprint （对比 ATMEGA329P-20MUR)
- 32 KB right-sized Flash keeps cost down （对比 ATMEGA645P-20MUR)
设计说明
The 1.8-5.5 V range hides an important constraint: maximum clock frequency is supply-dependent. At 5 V the core runs at 20 MHz, but near 1.8 V the safe frequency is much lower (per the frequency-vs-voltage curve in the manufacturer datasheet). If your application must run 20 MHz at all times, regulate the supply to at least ~4.5 V or use a boost converter; if running from batteries, consider dynamic clock switching between active and sleep phases to combine throughput with picoPower savings.
The 64-QFN MLF package has an exposed die pad that must be soldered to a grounded copper pour. Use a ~3x3 (or larger) via array under the pad to tie it to internal ground planes - this is required for mechanical reliability and aids heat spreading, per Microchip MLF application guidance. For reflow, the pad aperture on the stencil should be patterned (multiple small openings) rather than one large opening to avoid voiding and floating the package.
ATmega325-family MCUs use fuse bytes for clock source, BOD, and JTAG configuration; an incorrect CKSEL fuse selection can brick boards with only ISP access. Set the JTAGEN fuse deliberately: leaving JTAG enabled shares four port pins (JTAG default on) which reduces available I/O if you expected full port width. Verify signature and lock-bit programming on the programming fixture before release builds, and confirm EEPROM preservation settings so field firmware updates do not erase calibration data.
Decouple each VCC/AVCC pin pair with 100 nF ceramics placed within a few millimeters of the pads, plus one bulk 4.7-10 uF per supply domain. Keep the ADC analog supply (AVCC) filtered with an LC or RC network when switching loads (relays, LEDs) share the 5 V rail; ADC reference noise directly appears as code jitter in the 10-bit converter. Route the crystal (if used) short and guarded by ground, away from PWM and relay traces.
合规信息
Distributor listings describe the part as GREEN packaging with industrial temperature range, indicating RoHS/lead-free/halogen-free compliance. AEC-Q100 qualification is not claimed in the provided data.
