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DOWO SMA4742A
Configuration
1 options
Configuration
26+
Available for RFQ
Technical data
Product details
19
specifications
Core information
- Product name
- DOWO SMA4742A
- Type
- DOWO
- Minimum package
- 5000 圆盘
Technical parameters
- Electronic Component
- Electronic Component
- Electronic Component
- DOWO
- Electronic Component
- SMA4742A
- Electronic Component
- 1
- Package
- SMA
- Electronic Component
- Zener Diode
- Electronic Component
- 0.123g
- Electronic Component
- 1
- (Zzk)
- 700Ω
- (Zzt)
- 21Ω
- Electronic Component
- BM0257247599
- Diode
- 1
- Current(Ir)
- [email protected]
- Power Dissipation(Pd)
- 1W
- Electronic Component
- 55℃~+150℃
- Electronic Component
- Electronic Component
For datasheets, package documents, compatible-part guidance, or other technical resources, contact WMSIC customer service. Availability is confirmed case by case.
SMA4742A 产品概述
一、产品简介
SMA4742A 是东沃（DOWO）推出的一款瞬态抑制二极管（TVS）封装器件，采用常用的 SMA 表面贴装封装，针对直流母线与信号线的过压冲击与静电放电提供保护。器件标称稳压值为 12V，适合用于中等电压等级的电源保护与接口保护场合。
二、关键参数解读
- 稳压值（标称）：12V —— 作为工作电压或转折电压的参考，应结合实际线路电压选择；
- 反向电流 Ir：100 nA @ 9.1V —— 在接近工作电压以下时漏电低，适合对待机功耗敏感的电路；
- 耗散功率 Pd：1 W —— 指稳态下器件在规定条件下可耗散的功率，适用于中小幅度、短时脉冲的能量释放；
- 阻抗 Zzt：21 Ω —— 在指定测试条件下的动态阻抗，反映器件对高频或快速脉冲的钳位能力；
- 阻抗 Zzk：700 Ω —— 通常为低电流水平下的阻抗指标，体现器件在微小脉冲下的响应特性；
- 工作结温范围：-55 ℃ ~ +150 ℃ —— 宽温范围适应工业级和恶劣环境应用需求。
以上参数共同决定了器件在不同脉冲幅度、频率与温度条件下的保护表现。
三、典型应用
- 汽车电子的辅助电源和通信线路保护（在允许的温度与功率条件下）；
- 工业控制系统的 12V 或相近电压母线防护；
- 通信接口、数据线和传感器线路的抗静电与浪涌保护；
- 需要低漏电、低待机功耗的便携或嵌入式设备的输入保护。
四、封装与安装
SMA 封装适合高速贴片装配与回流焊工艺。布局建议：
- 将 TVS 器件尽量靠近被保护的输入端或电源入口，减小串联走线长度；
- 采用合适的焊盘和热量控制设计，保证回流焊温度曲线与制造工艺兼容；
- 对于高能量冲击场合，设计旁路或散热路径以协助能量分散。
五、选型与使用建议
- 若保护对象为 12V 恒压线或近似电压，应确认稳压值与电路允许的钳位电压匹配；
- 注意到底层电路对瞬态钳位电压的耐受性，必要时并联更高功率或更低阻抗的保护器件；
- 考虑到 Pd 为 1W，若可能遭受高能量冲击，应设计外部限流或采用更高能量等级的 TVS；
- 验证工作环境温度，长期高温运行会影响器件寿命与参数稳定性。
六、可靠性与环境适应性
SMA4742A 的工作结温范围宽，适应工业级温度循环与苛刻环境。实际应用中建议关注热循环、焊接可靠性及长期电压应力，以保证长期稳定工作。厂商提供的具体冲击/ESD 等测试报告可用于进一步评估在目标应用中的可靠性。
综上，SMA4742A 是一款面向中低功率、低漏电、宽温范围的瞬态抑制器件，适用于需要稳态低漏电并兼顾一定冲击抑制能力的 12V 级保护场合。
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