Hey.
We make design with the LT1763 to output 5V with 250mA.
We enter the the card to oven to check the functionality in high and low temperature.
In this test we measured the voltage in two places
1) In the card with A/D (accurate measured)
2) With resistor to act has load. it not accurate because we measured between the legs of the resistor. so the ground was not absolute zero.
we start the with 85 degree for 4 hours and the card output 5V.
after the 4 hours we start to cool to -40 degree .
when we start to coll down the output voltage decrease to 4.7V.
we check the feedback resistor and they capable to be in -55 to 150 degree
according the datasheet the LT1763 work from -40 to 125.
we put thermocouple on the LT1762 when it worked and the temperature was -20 to 92.
what can cause this problem?
I add the schematics of the design and the data from the test.
The data of the output voltage is not accurate and showed we have 4.6V , when i read from the A/D the voltage was 4.7V.
The data start when we cool the oven , the card was in 85 degree for 4 hours
