Tool/software:
Hi,
TPS62291DRV - This is the IC we are using in our product.
Product powered by usb (5VDC) & that is supplied to Vin, EN & Mode pin.
We did Damp Heat Cyclic (Thermal)Test for the product.
Test description:
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Temperature: 30°C at 95% RH and 55°C at 93% RH with non-condensing.
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Number of Cycles: 2 cycles
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Duration: 12 hours dwell per cycle
6Hrs on 30degree & 6Hrs on 55degree with the above-mentioned humidity in a cycle.
The ramp up from 30°C to 55°C will be happening at a rate of 3 degree/ min and this time is excluded from the dwell time.
Issue:
After the thermal test 2 Products didn't work, the root cause for both product's failure is TPS62291DRV's output side failure.
One board is shorted on O/P side (SW to gnd).
Other board is giving 2.9V as O/p for a short time (less than a min) & goes to 0.3V. This is also checked with isolating the regulator from rest of the circuit.
Did observe 60 & 144ohms impedance in both boards across Vin to Gnd pin.
Pls share the cause of behavior of this regulator.
Regards,
C.Hari
