Hi all,
Firstly, what is the maximum and minimum value of input bias current ADS1282? ADS1282 datasheet states only typical value of input bias current.
Secondly, i didn't see any information about analog inputs leakage current which is leaked by ESD diodes and multiplexer. These informations are critical for my design.
Regards,
Eren
Hi Eren,
Unfortunately, I'm not able to place an official upper and lower limit on the input bias current specification. To truly qualify limits on these specifications they would need to be fully characterized and or measured at final test to ensure that the product was in compliance with the datasheet specs.
....From the data I have seen on this, the maximum input bias current may be around 2-3x times the typical value, but again that is not a value I can guarantee.
...We have looked at the input bias current vs input voltage and temperature and here is the typical data on those relationships:
As far as leakage current caused by ESD diodes, to some extent that information is included in the input bias current specification. However, input bias current likely only accounts for the ESD leakage that occurs within the normal input common-mode range of the PGA. Violating the input common-mode range and applying (absolute) input voltages that approach (or even exceed) the AVDD or AVSS supply voltages will certain cause a significant increase in ESD leakage current.
In practice, you will likely need to design your own external ESD or over-voltage protection circuitry since the internal ESD protection is mostly designed for protecting the device during handling and assembly. For protecting against higher-power transient events in the field, larger ESD diodes and external components are required. These devices will often have much higher leakage currents, so do pay special attention to the leakage currents of the components used on the analog inputs as these leakages are almost always larger.
I hope that information helps!
Best regards,
Chris
