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ATL431: Reference Current
Part Number: ATL431
I am looking to use the ATL431 as a comparator, as shown in SLVSCV5D Figure 30. In this application, the "Vin" of Figure 30 is a higher voltage signal, so "Rin" is actually a resistive voltage divider to get the voltage down to the 2.5V reference when the signal exceeds a threshold.
Paragraph 22.214.171.124.3.1 states "Because Iref can be as high as 0.15 μA, TI recommends to use a resistance small enough that will mitigate the error that Iref creates from Vin. Also, the input resistance must be set high enough as to not surpass the absolute maximum of 10 mA."
1. The first part of the sentence "Iref can be as high as 0.15 μA", this is taken from 6.5 "Electrical Characteristics" and Iref uses Test Circuit Figure 23 to establish the 150nA. However this aligns with the shunt regulator schematic of Figure 32, not the comparator schematic of Figure 30. Therefore, is this still an appropriate number to use for the comparator application? If not, what should I be using instead?
2. The second part of the sentence "to not surpass the absolute maximum of 10 mA" does this suggests the Iref is dynamic? How can Iref become 10mA? Or, what is the 10mA referring to?
The purpose of these questions is determine how to calculate the Vref tolerance, given the comparator application.
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