Requirement:
- Vout = 16V, 250mA
- Vin = 12V, 2Amp
- Supply must be with current limit of 250mA
- It should also have short circuit protection.
Tried Solution:
We used simple switcher LMR62014 to boost the voltage from 12V to 16V and it is working fine. For current limiting we put made circuit like below image where N-Channel Mosfet and 1Ohm Shunt is between Ground and Load and based on set current limit of 250mA at LM741 OpAmp Mosfet controls the current. Now with this setup when we make short circuit in circuit than MOSFET operates in linear region and all 16V, 250mA gets dropped across Mosfet and it makes Mosfet very hot which is damaging PCB as well.
(Note: We had used small package SMD mosfet before to CSD18535 Power mosfet but because of they were going beyond Safe operation area they were getting burnt).
Required Solution:
I believe that the way we are implementing the solution for limiting current is not correct and we need a standard solution / Reference design with part no. followed by industry for any such application. So, we need feedback for all possible technical ways to have this requirement working in our circuit with any suggested part no. or reference design.
