ADS1112: Input port damage issue

Hi,


Based on the schematic, there isn't anything that should cause damage to the device. Using an input connected to a reference voltage should be a safe measurement. However, if there are problems, I'll need to know more information.

First, how does the customer know that the device is damaged? Do the inputs appear unconnected? Under what conditions does this damage occur? I've made many measurements with this device and have never had a device input break down. Are there any high voltage connections on this board? Does the reference voltage spike the input? If the input is contained between 0V and 5V, I don't see how the input can be damaged.

One possible problem is that there are large inductors on the supply. With digital currents found in the ADC (and possibly on the startup in-rush current for the board), the switching currents for the ADC can cause large changes in the supply voltage from the L(dI/dt). However I find that this is unlikely to do damage, but it may be possible to disrupt the digital sections of ADCs.

Regardless, I don't know of any cases where the inputs are damaged without some sort of over-voltage or ESD event occurring to the device.


Joseph Wu

Hi,


I haven't heard from you for a while, so I thought I'd ask if your customer had solved this problem. I'll close this post for now, but if there's more information, you should be able to reply and re-open this post.

Again, if there is more information, or further questions you need to ask, just reply to this post.


Joseph Wu

Unfortunately, it was not resolved and changed to ADC1120.
And We do not know why this symptom is occurred.