[经验]

汽车应用中的ESD威胁

2018-10-12 11:53:47

1500 安森美 ESD

目前市场上的大多数硅ESD保护解决方案主要是针对消费类设备而设计的，但ESD威胁也使汽车电子设计师在夜间保持活力。
汽车设计人员不仅担心“正常”的ESD情况，而且其他汽车特定事件也引起严重关注，其中一个问题是电池状况不足。
汽车中的电池短路事件发生在车辆中这些装置的组装，服务或消费者使用期间。
在组装和维修期间，电池线路断开或暴露可能会连接到其中一个接口，从而可能对ESD保护装置造成损坏。
在消费者使用期间电池短路的一个很好的例子是USB电缆悬挂在车辆的点烟器插座中，再次将电池线电压引入接口线。
汽车环境中仅存在12V电池网络会给汽车ESD保护设备带来额外负担，因为它们需要能够承受有意或无意地将这些接口短路到电池线的人。因此，如果接口是
除了ESD威胁之外，要求承受如此短的电池状态，主要用于消费设备的正常5V击穿ESD器件将不适合。
安森美半导体开发了具有这种短路电池性能的汽车目标ESD保护器件，此外还考虑了其他高速ESD保护要求，例如在更高带宽下的低插入损耗和用于信号完整性的极低电容。
ESD7002，ESD7361和ESD7461等器件具有至少16V的击穿电压，可以在汽车短路电池条件下保持生存能力，电池电压范围最小为9V至最大16V。
这些器件提供极低的钳位ESD保护，同时为可能达到GHz频率的应用实现极低的电容。

以上来自于谷歌翻译

以下为原文

Most silicon ESD protection solutions in the market today are mainly designed for consumer devices in mind, but ESD threats also keep automotive electronic designers up at night.  Not only are automotive designers worried about the “normal” ESD situations, but additional automotive specific events are a cause for serious concern one of which is a short to battery condition.
The short to battery event in automotive occurs during assembly, service or consumer use of these devices in the vehicle.  During assembly and service, there is a potential for a broken or exposed battery line to connect to one of these interfaces causing potential damage to the ESD protection device.  A good example of short to battery during consumer use is a USB cable dangling into the cigarette lighter socket of the vehicle once again introducing battery line voltage to the interface lines.  The mere existence of the 12V battery network in the automotive environment puts an additional burden on the automotive ESD protection devices as they need to be able to withstand someone intentionally or unintentionally shorting these interfaces to the battery line. As a result, if the interface is required to withstand such a short to battery condition in addition to the ESD threats, the normal 5V breakdown ESD devices used mainly in consumer devices will not be suitable.

ON Semiconductor has developed automotive targeted ESD protection devices with this short to battery capability in mind, in addition to the rest of the high speed ESD protection requirements such as low insertion loss at higher bandwidth and very low capacitance for signal integrity.
Devices such as the ESD7002, ESD7361, and ESD7461 have a minimum 16V breakdown voltage to allow survivability in automotive short to battery conditions where the battery voltage can range from 9V minimum to 16V maximum.  These devices provide very low clamping ESD protection while achieving very low capacitance for applications that may go into GHz frequencies.