Other Parts Discussed in Thread: ALM2403-Q1
My customer wants to use ALM2403-Q1 as a resolver excitation driver, but is also considering ALM2402F for this purpose. From normal use case point of view, there is no problem. But we are concerned about automotive short-circuit scenarios that may destroy the ALM2402F-Q1 more easily than an ALM2403 because of higher supply voltage specification of the latter one.
In case of short-circuit to battery, voltages up to 40 V may occur (truck battery voltages). We are using the protective circuit fom the application notes, so continuous short-circuit to 40 V and more will not be able to harm the ALM2402F, as the blocking capacitor will not conduct this voltage to the output of the IC (the capacitor is not in the feedback loop for this reason, so no excessive voltage can occur on the - input pin). But at the time when the voltage suddenly rises from about 6 - 7 V to 40 V, the capacitor will conduct for a short time until it is charged. So a transient spike will occur on the ALM2402F output. We do our best by using series resistors and protective diodes to soften the blow. But still we are concerned because the voltage spike may exceed the maximum rating of 18 V.
My question therefore is:
Can you provide a transient or pulse specification on the maximum voltage on the outputs of the ALM2402F? Or can you specify a maximum clamping current to supply (I anticipate that the output pin has internal diode to V+)? Or do I have to rely solely on the 18 V maximum rating?
best regards Martin