LMV7231: Resistor Divider for LMV7231

Hi Elder,

if you need high precision, you should use 0.1% resistors anyway, instead of 1% resistors. But then it makes no difference whether you take two separate voltage dividers or the three resistor network. The only advantage of the two separate voltage dividers is that you can set the thresholds individually. With the three resistor network the settings do interfere with each other and it might be more difficult to find the proper resistances. But apart from that I don't see any advantage of using two separate voltage dividers.

Kai

Hello Elder,

What I meant by "accuracy" was that the three-resistor divider does not allow for as much "fine-tuning" of the tap voltages due to the available resistor combinations.

One advantage of the three resistor string is a savings in quiescent current, since the string current is shared per channel, and also saving one resistor per channel (space/cost).

Another trick is to use two multi-tap resistor strings on the positive and negative input sides to save even more current (and resistors).

Keep in mind that the trim scheme trims the actual input threshold voltages, so the 1.5% takes into account the internal reference error and comparator offset voltages. So you do not have to add reference voltage error and comparator offset to your error calculations.