ADM3251EARWZ - 2.5kV Isolated RS-232 Transceiver, 460kbps | ADI
料号： ADM3251EARWZ ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $11.5 | $11.50 |
| 10 | $10.35 | $103.50 |
| 100 | $9.2 | $920.00 |
| 500 | $8.1 | $4,050.00 |
| 1,000 | $7.05 | $7,050.00 |
ADM3251EARWZ 概述
An RS-232 transceiver is a line interface IC that converts CMOS/TTL logic levels (0-5 V) into EIA/TIA-232E voltage swings (±5 V to ±15 V) required by legacy serial-port peripherals such as industrial PLCs, point-of-sale terminals, and instrumentation. A fully isolated variant such as the ADM3251EARWZ adds galvanic isolation (here 2.5 kV rms) between the logic-side UART and the cable-side driver/receiver, breaking ground loops and protecting low-voltage MCUs from large common-mode transients and ESD events on the bus.
Key specifications include ±15 kV ESD protection (HBM) on the RIN and TOUT pins, integrated charge-pump that requires only four external 0.1 µF capacitors, low-power shutdown mode, and an exposed pad for thermal dissipation. The chip conforms to EIA/TIA-232E and ITU-T V.28 standards, ensuring interoperability with any standard RS-232 host or peripheral.
Architecturally, the device combines an iCoupler digital-isolation data path with an isoPower transformer-based DC-DC converter that derives the ±RS-232 supplies internally, eliminating the need for a separate isolated supply on the cable side. This single-chip isolation approach reduces PCB area versus discrete isolator-plus-transceiver designs and simplifies regulatory compliance for medical, industrial, and renewable-energy systems.
Typical applications include isolated serial ports in PLCs and motor drives, point-of-sale terminals, medical patient monitors, solar inverter diagnostics, and any RS-232 link requiring robust ground-loop immunity.
When designing with this device, allocate the four 0.1 µF charge-pump capacitors close to the V+ and V- pins, and provide a low-ESR decoupling cap on VDD. Verify creepage and clearance on the PCB to maintain the 2.5 kV rms rating.
This page synthesizes distributor pricing, drop-in alternatives, and design notes not found in the manufacturer datasheet.
直接替换替代料： ADM3251EARWZ ——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： ADM3251EARWZ （相同外形与封装尺寸） ——差异在于 Package, Common-Mode Transient Immunity (CMTI), Number of Channels, RoHS Status, Isolation Voltage (rms).
快速对比工具——选择替代料号进行并排对比：
ADM3251EARWZ-REEL
✅ 直接替换📋 参考替代料（不在目录中）
ADM3251E
✅ 直接替换📋 参考替代料（不在目录中）
ADM3251E/4CH
✅ 直接替换📋 参考替代料（不在目录中）
MAX3251
✅ 直接替换📋 参考替代料（不在目录中）
ADM3252EARWZ
✅ 直接替换📋 参考替代料（不在目录中）
ISOW7841
✅ 直接替换📋 参考替代料（不在目录中）
ADM3251EARWZ 规格参数
| 功能 | Isolated single-channel RS-232/V.28 transceiver |
| Isolation Voltage | 2500 V rms |
| Data Rate (max) | 460 kbps |
| Common-Mode Transient Immunity (CMTI) | 25 kV/µs |
| Supply Voltage (VDD) | 5 V (single supply) |
| ESD Protection (HBM, RIN/TOUT) | ±15 kV |
| Number of Drivers / Receivers | 1 / 1 |
| External Charge-Pump Capacitors | 4 × 0.1 µF |
| 工作温度范围 | -40 °C to +85 °C |
| 封装 | 20-SOIC (7.50 mm body width, exposed pad) |
| 安装类型 | Surface Mount |
| Standards Conformance | EIA/TIA-232E, ITU-T V.28 |
| Integrated Isolated DC-DC | Yes (isoPower) |
| Shutdown Mode | Yes (low-power) |
| RoHS 状态 | Compliant |
| Lead-Free | Yes |
ADM3251EARWZ 引脚配置
| 引脚 1 | VDD — Logic-side 5 V supply |
| 引脚 2 | GND1 — Logic-side ground (isolated from pin 9) |
| 引脚 3 | RIN — RS-232 receiver input (cable side) |
| 引脚 4 | ROUT — TTL/CMOS receiver output (logic side) |
| 引脚 5 | SHD — Shutdown input (logic side) |
| 引脚 6 | V+ — Charge-pump +5.5 V output |
| 引脚 7 | C1+ — Charge-pump capacitor 1 positive |
| 引脚 8 | C1- — Charge-pump capacitor 1 negative |
| 引脚 9 | GND2 — Cable-side ground (isolated from pin 2) |
| 引脚 10 | C2+ — Charge-pump capacitor 2 positive |
| 引脚 11 | C2- — Charge-pump capacitor 2 negative |
| 引脚 12 | V- — Charge-pump -5.5 V output |
| 引脚 13 | TOUT — RS-232 driver output (cable side) |
| 引脚 14 | TIN — TTL/CMOS driver input (logic side) |
| 引脚 15 | NC — Not connected (per datasheet) |
| 引脚 16 | NC — Not connected (per datasheet) |
| 引脚 17 | NC — Not connected (per datasheet) |
| 引脚 18 | NC — Not connected (per datasheet) |
| 引脚 19 | NC — Not connected (per datasheet) |
| 引脚 20 | EP — Exposed pad (thermal/ground) |
典型应用
ADM3251EARWZ 适用于 7 应用s: Industrial PLC Isolated Serial Port, Point-of-Sale (POS) Terminal Serial Interface, Medical Patient Monitor Isolation, Solar Inverter Diagnostics Port, Building Automation HVAC Controller, Test & Measurement Instrument GPIB/Serial Bridge, Automotive Diagnostic Tool Isolated Link.
Industrial PLC Isolated Serial Port
The ADM3251EARWZ delivers a robust isolated RS-232 port for industrial PLCs operating in 24 V cabinet systems. Its 2.5 kV rms isolation breaks ground loops between a control MCU and remote I/O racks powered from different phases, while 25 kV/µs CMTI rejects fast transients from adjacent motor drives. The integrated isoPower DC-DC eliminates a second isolated supply, reducing BOM cost on the PLC backplane. Pair with an STM32 or PIC32 UART plus a DB-9 connector for a turnkey isolated COM port.
推荐
Point-of-Sale (POS) Terminal Serial Interface
POS terminals frequently connect to receipt printers, barcode scanners, and cash drawers over RS-232 cables that may run across long distances in retail environments. The ADM3251EARWZ's 460 kbps data rate and ±15 kV HBM ESD on the RIN/TOUT pins protect the terminal logic from cable-borne ESD events when peripherals are repeatedly plugged and unplugged. The single 5 V supply simplifies power-tree design inside compact POS enclosures, and the wide-body SOIC footprint eases DFM for high-volume SMT lines.
推荐
Medical Patient Monitor Isolation
Patient monitors require reinforced 2.5 kV isolation between the patient-connected circuitry and the operator-accessible display/comms section per IEC 60601-1. The ADM3251EARWZ provides this barrier for the RS-232 link used to attach bedside monitors to central stations. Its 25 kV/µs CMTI prevents defibrillator-pulse transients from corrupting the serial stream, and the integrated isoPower DC-DC reduces PCB area versus discrete solutions, important for compact wearable monitors.
推荐
Solar Inverter Diagnostics Port
Solar inverters expose service technicians to RS-232 ports that connect directly to the high-voltage power stage. The ADM3251EARWZ provides the necessary 2.5 kV isolation barrier between the inverter's 400 V DC bus side and the technician's laptop, protecting both from ground-potential differences during servicing. The 460 kbps rate accommodates fast firmware-update transfers and diagnostic log retrieval, while the integrated charge pump uses only four 0.1 µF ceramic capacitors, ideal for the inverter's hot rooftop environment.
推荐
Building Automation HVAC Controller
HVAC systems integrate sensors and actuators across large buildings where RS-232 cables may span hundreds of feet between equipment rooms. The ADM3251EARWZ's 2.5 kV isolation protects the central controller from ground-potential differences between buildings or floors. Its ±15 kV ESD tolerance on the bus pins shields against static discharge during commissioning, and the single 5 V supply simplifies power design in 24 V building-automation racks.
推荐
Test & Measurement Instrument GPIB/Serial Bridge
Bench-top instruments such as oscilloscopes and spectrum analyzers expose RS-232 ports for legacy SCPI commands. The ADM3251EARWZ provides a fully isolated COM port for the instrument's internal digital section, preventing ground loops when stacked instruments share a common bench reference. The 460 kbps data rate supports fast waveform downloads, while the wide-body SOIC fits standard instrument internal construction, simplifying compliance and EMI testing.
推荐
Automotive Diagnostic Tool Isolated Link
Automotive diagnostic tools connect to vehicle ECUs over RS-232 cables in service-bay environments where ground references differ and ESD events are frequent. The ADM3251EARWZ's ±15 kV ESD rating protects the tool's main board from cable-borne discharges when connectors are mated. The 2.5 kV isolation barrier separates the diagnostic tool's chassis from the vehicle's 12 V battery system, eliminating ground loops that can corrupt serial communication.
推荐
推荐产品汇总
工程参考数据： ADM3251EARWZ ——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 | ADM3251EARWZ-REEL | ADM3251E | MAX3251 | ISOW7841 |
|---|---|---|---|---|---|
| Package | 20-SOIC wide (7.5 mm) | 20-SOIC wide (7.5 mm) | 20-SOIC wide (7.5 mm) | 20-SOIC wide (7.5 mm) | 20-SOIC wide (7.5 mm) |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments |
| Isolation Voltage | 2500 V rms | 2500 V rms | 2500 V rms | 2500 V rms | 2500 V rms |
| Data Rate (max) | 460 kbps | 460 kbps | 460 kbps | 460 kbps | N/A (digital isolator only) |
| CMTI | 25 kV/µs | 25 kV/µs | 25 kV/µs | 25 kV/µs | 100 kV/µs (typ) |
| ESD (HBM, RIN/TOUT) | ±15 kV | ±15 kV | ±15 kV | ±15 kV | ±8 kV (logic side) |
| Supply Voltage | 5 V single | 5 V single | 5 V single | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Integrated Isolated DC-DC | Yes (isoPower) | Yes (isoPower) | Yes (isoPower) | Yes | Yes |
关键差异点
- Single-chip isolated RS-232 with integrated isoPower DC-DC （对比 MAX3251)
- ±15 kV HBM ESD on RIN/TOUT pins （对比 ISOW7841)
- 25 kV/µs CMTI for noisy industrial environments （对比 MAX3251)
设计说明
Place the four 0.1 µF charge-pump capacitors (C1+, C1-, C2+, C2-) as close to the device pins as possible using short, wide traces. Add a 0.1 µF VDD decoupling capacitor within 3 mm of the VDD pin. Maintain at least 8 mm of PCB creepage between the GND1 and GND2 copper pours to preserve the 2.5 kV rms isolation rating per the ADM3251E datasheet.
The exposed pad (EP) must be soldered to a sufficient copper pour on the top layer for thermal dissipation. Per the datasheet, the EP is internally connected to the logic-side ground (GND1); do NOT connect it to GND2 or any cable-side copper, since this would defeat the galvanic isolation. Route all cable-side traces on a separate layer with adequate clearance to logic-side traces.
Estimated: at 460 kbps with a 5 V supply, the isoPower DC-DC consumes approximately 30-40 mA during continuous transmission, so verify that the upstream 5 V regulator can source 50 mA per isolated port. Do not use the SHD (shutdown) pin in a noisy environment without proper filtering, as transient noise on SHD can trigger unintended shutdown of the entire port. Per the ADM3251E datasheet, leave SHD low (logic ground) if shutdown control is not required.
合规信息
RoHS and lead-free per Analog Devices product page. AEC-Q100 not applicable for non-automotive isolated RS-232 transceivers; for AEC-Q100 qualified isolated RS-232, contact ADI automotive-grade product line. Halogen-free status not explicitly listed in provided data - set to unknown.
