Maximum Voltage on Enable Input?

Can the enable input be at the maximum supply input voltage when Vin=0 V (to turn on the regulator)?

If not, what’s the maximum voltage? Or, must a series resistor be used to limit current?

These regulators:

D24V22 5V output
D36V50 12V output


For the D24V22F5 there is a 6.5V clamping diode on the EN pin, so you can connect it to any voltage up to the supply voltage through an appropriate in-line resistor (a few hundred kilohms should be fine). For the D36V50F12 the EN pin can handle voltages up to 55V irrespective of the VIN voltage. However, we generally recommend against applying voltages to pins on electronics that are not powered. Is it possible for your EN signal source to be open-drain? In other words, can you have it drive low only when you want to disable the regulator and remain floating (allowing the EN pins to be pulled up to VIN on the regulator) otherwise?