CT=33nF, VDD=3.3V, /RESET pullup=100K@3.3V,
/MR pullup=5K@ 3.3V
SENSE voltage divider 665K/100K, sense deglitch cap=2.2uF(because 1nF was allowing glitch resets)
We have a group of TPS3808G01 parts that appear to be defective. The /RESET either will not leave the reset state or the output driver appears to not be in saturation. The /RESET voltage sometimes 2.7V with 100K pullup to 3.3V. There is no other load on the /RESET pin other than the pullup.
The voltage on CT appears to be in some strange state on defective components. When measured with DMM the voltage is commonly ~.7-.9 voltage. I'm assuming this pin is controlled by a one shot multivibrator and once it hits the threshold voltage of 1.23V it resets to 0V on pin CT. This 0V expected behavior is observed on parts functioning as expected but not on defective parts.
The SENSE voltage also is observed to be high on defective parts. Expected behavior is for SENSE pin to be ~0.420 but defective parts are measuring ~1V on SENSE.
Is this due to leakage on SENSE and CT pins? Are these factory defects or something in the design causing EOS damage. The application appears to be in accordance with the datasheet with the exception of the 2.2uF on SENSE. Is there a concern with excessive capacitance on SENSE?