Other Parts Discussed in Thread: TPS61240
I am using TPS61073 IC as a 3.3 VDC to 5 VDC booster in adjustable mode with the feedback resistor values R1 = 2M, R2 = 220k.
I am enabling the IC using one of the micro-controller port with 3.3 V (same as input) supply through a pull down resistor of 100k (to avoid floating state). Please refer schematic below:
I was facing two issues in my design, detailed as:
1. IC heating up and emerging of fault condition (STILL NOT DETECTED WHAT EXACTLY HAPPENED INSIDE) in the IC resulting in output voltage = input voltage.
Corrective actions - I found that due to the pull down resistor value - 100k at enable pin the current consumption at enable pin was more than rated as per the datasheet.
I changed the pull down resistor value to 20M and limited the current to 0.16 uA which is now less than 0.3 uA as declared by the datasheet.
I understood that due to over current supply the problem occurred (Please correct me if I am wrong here). Secondly, I want to know what exactly got damaged inside the IC ?
2. The second problem which is still occurring is regarding ESD. As soon as I touch the area over 2M resistor and the output capacitors, the IC shuts down producing output voltage = input voltage.
Corrective actions - Currently I have no other option than potting the whole circuit. Please help me with some solution so that I don't have to encapsulate the whole circuitry.