My VDD or Vout is shorted to ground. I appear to have an over voltage failure. How do I fix this?
The most common cause for this is that the output exceeds VDD by 0.5V or VDD exceeded its maximum rating by 0.5V. If either of these events occurs in your system then an electrical over stress (EOS) has occurred and can cause this type of permanent damage. To eliminate this issue the best thing to do is determine the source of the event and eliminate it. If not possible, then add transient voltage suppressors as a safeguard.
Silicon Lab's family of ultra-low-power digital isolators are CMOS devices offering substantial data rate, propagation delay, power, size, reliability, and external BOM advantages over legacy isolation technologies. The operating parameters of these products remain stable across wide temperature ranges and throughout device service life for ease of design and highly uniform performance. Recently a new generation of digital isolators, the Si86xx family, was introduced to expand and enhance Silicon Labs isolation portfolio.
As before, data rates up to 150 Mbps are supported, and all devices achieve propagation delays of less than 10 ns. Additionally enable inputs provide a single point control for enabling and disabling output drive. Ordering options include a choice of isolation ratings (1, 2.5, 3.75 and 5 kV) and a selectable fail-safe operating mode to control the default output state during power loss. All products >1 kVRMS are safety certified by UL, CSA, and VDE, and products in wide-body packages support reinforced insulation withstanding up to 5 kVRMS.
The Si86xx family has several improvements over their lower cost drop-in compatibles Si84xx counterpart: Specifically the Si86xx family offers:
Reinforced insulation withstanding up to 5 kVRMS.
Improved regulator for 50x higher PSRR
Lower frequency oscillators for lower power operation and even lower EMI
Up to 6 isolation channels rated at 5kVRMS
Tighter receiver band pass for improved CMTI: 35kV/mS(min), 50kV/mS(typ)
Faster output buffer with exactly 50 ohm output termination for tighter output impedance matching
Minimum operating VDD = 2.5V
Schmitt trigger input for higher input noise rejection
在隔离栅任意侧发生过压故障时，仅会对隔离栅发生故障一侧的内部电路产生损坏。也就是说如果A侧发生过压故障，导致接地或电源短路，那么B侧不会发生故障或短路。B侧仍然会根据数据表中的规定继续操作，多数情况下会返回到默认输出。如果B侧出现故障而不是A侧，情况会一样，A侧会依照数据表运作，而B侧会在"Device Operation"部分“listed as UP”。了解这些情况对于故障检测系统是十分重要的!
If I over-voltage Side-A of a Si86xx Digital Isolator, what happens to Side-B?
During an over-voltage failure on either side of the isolation barrier, there will be damage to the internal circuitry only on that side of the isolation barrier.
This is to say that if an over-voltage failure on Side-A causes a short to ground or power, there will not be failure or short on Side-B. Side-B will continue to operate as defined in the datasheet, which most often means returning to its default outputs.
The situation is the same when Side-B experiences failures and Side-A does not: Side-A functions according to the data sheet, where Side-B is listed as UP in the "Device Operation" section.
Knowing what happens in such a scenario can be crucial for fault-detection systems!
Where can I download the schematic source file for a Silicon Labs board?
PDFs for board schematics are available in the board's corresponding User's Guide. If you need source files for this schematic or schematic symbols, please contact technical support for assistance by going to Support > Technical Support on the website or by going to http://www.silabs.com/support/resources.