Recently we have been seeing a high failure rate on boards using the REF3225 part. We found that the shutdown current of the REF3225 was very high at 500uA (should be 1uA or less). The input (IN) of the REF3225 was powered by 3.6V and ENABLE was 0V.
The REF3225 parts with high shutdown current were from 250 piece reels with date code 1948. These reels were sealed until the time of assembly. Are there any known defects on parts from this date code?
We are looking to get technical support for part number REF3225 (REF3225AIDBV). What we are finding is that power up conditions may be causing the high 500uA shutdown current. However, the power up sequencing appears to be within the specifications in the datasheet. I have attached images of the REF3225 circuit we are using and an oscilloscope capture of the power up sequencing. The signal ASEL is being driven by a microcontroller.
CH1: IN (Pin 4)
CH2: ASEL (U2 Pin 2)
CH3: ENABLE (Pin 3)
Are there any potential power up sequencing issues (or any other issues) not listed in the datasheet that we should be concerned about? We started seeing this issue within the last 6 months. Could it be an issue with one or more of the date codes that I mentioned (1948, 1904, 1913, or 2308)? Note that the only known date code at this time with high shutdown current is 1948.
