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TL494 maximum voltage at the "feedback" pin
Document SLVA001D figure 10 indicates the maximum voltage at the feedback pin cannot exceed the 5V internal regulator voltage.
Is this true?
What happes if the voltage on the feedback pin gets higher than 5V?
is there a safety mechanism or does the part gets damaged??
The Ct maximum voltage acording to page 7 of SLVA001D is 3 volts. Why would you need to go above 4 volts let alone the 5 volt internal reference.
The simle answer is keep the voltage below the 5 volts of the internal reference or you might turnon parasitic transistors that could damage the internal workings of the device. There is no protection mechanism built into the device. This pin is meant as an output not an input and as an output it would never go above the source voltage.
I agree that Ct should not be used as an input but I beleive we have a mis communicatio here.
The customer would like to know the max voltage allowed on the feedback pin, pin 4, not Ct which is pin 5.
SInce the circuit attached to pin 4 is also powered via the on board regulator, my guess is that 5V is the absolute maximum input voltage on that pin.
Is this pin also not protected against overvoltage ??
This part was developed in either Japan or in Dallas and transfered under our group. In either case, I do not have the schematics so can not answer questions on ESD and pin protection.
As far as driving the error amplifiers outputs high the short answer is "Do not do that."
If you exceed the Vref voltage you will might turn on internal parasitic transistors and either have unintended conditions or a saturated comparator which might take a long time to operate.
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