跳转至主要内容

Bill Russell

近期文章

多少保护才足够?

Bill Russell 发表于 2021 年 1 月 14 日

在设计电子系统时,必须考虑经常被忽视和低估的保护问题。设计人员有时会努力满足某些标准,如 IEC 61000-4-2 的抗静电 (ESD) 要求。安装在恶劣工作环境中的设备,如远程仪表、机器人和电信系统,将需要更高水平的雷电防护。这些是显而易见的要求。其他保护问题包括短路、电压尖峰、污电力、电缆放电事件等。面对所有这些瞬态威胁,设计人员可能会不知所措,心怀疑问:为确保可靠的系统,多少保护措施才算足够?

Read More

标签:电路保护

TVS 峰值脉冲功率:是不是越高越好?

Posted by Bill Russell on 15 April 2020

One of the most misunderstood ratings for transient voltage suppressor (TVS) diodes is peak pulse power (PPP). Many engineers will select surge protection components based primarily on rated peak pulse power and assume that their system will be well protected. After all, it seems logical to assume that a higher power rating means the device can absorb higher transient currents and therefore should be superior. While peak pulse power ratings may be considered in the selection process, the device should not be chosen solely on this parameter. To illustrate why, let us review the definition of TVS peak pulse power.

探索电路保护解决方案

Read More

标签:电路保护

TVS?只是个普通二极管,对不对?第二部分

Posted by Bill Russell on 18 March 2020

降低钳位电压

In part one, we learned transient voltage suppressor (TVS) clamping voltage is a key protection parameter. TVS manufacturers are constantly working to lower clamping voltage to keep up with ever shrinking IC geometries and increased sensitivity to overvoltage events. One method to achieve lower clamping is to engineer the device to “snapback” to a lower voltage once triggered. The snapback can be shallow, or deep depending on the intended application. One method of achieving a deep snapback is to design a self-triggering thyristor TVS structure (Figure 4).

探索电路保护解决方案

Read More

标签:电路保护

TVS只是个普通二极管吗?第一部分

Posted by Bill Russell on 12 March 2020

我记不清有多少人这么评价硅基瞬态电压抑制器 (TVS) 了。TVS 制造商可能也在随大流。我们通常将这些器件称为 TVS 二极管或静电放电 (ESD) 保护二极管。从技术上来说,二极管是一种两端子器件,主要沿一个方向传导电流。TVS 或 TVS 二极管也是两端子器件,用于在反向击穿区域中传导电流。如果把它看作“普通二极管”的话,我们是不是可以随便选择 TVS 二极管或相关类型的二极管来保护电路呢?真这样做的话,结果可能令人失望。

探索电路保护解决方案

Read More

标签:电路保护

以太网保护方法

Posted by Bill Russell on 19 February 2020

以太网端口会遭受外部瞬态事件,如静电放电 (ESD)、电气快速瞬变 (EFT)、闪电和电缆放电事件 (CDE)。外部瞬态电压抑制 (TVS) 二极管通常用于保护以太网 PHY 芯片免受这些威胁。但关于如何连接 TVS 二极管才能实现最大成效,人们仍有很多困惑。通常的建议是在 RJ-45 连接器附近用二极管连接每根信号线和接地线。实际上,TVS 应跨信号对连接,并位于连接器的 PHY 侧。在此博客中,我们将探讨其中的原因。

探索电路保护解决方案
Read More

标签:电路保护

工业应用中 RS-485 总线的瞬态保护

Posted by Bill Russell on 04 February 2020

Modern industrial networks rely on robust RS-485 communication links for long distance data transmission. These networks operate in harsh electromagnetic environments and must be capable of withstanding electrical overstress (EOS) events without damage. Semtech’s Protection Products Group application engineering team recently had the opportunity to work with Renesas Corporation engineers on a reference design for protecting Renesas’ fault-protected RS-485 transceivers, used in industrial applications.

探索电路保护解决方案

Read More

标签:电路保护

订阅博客

近期文章