LM5050-1: Can this part be used to implement a N-MOSFET based high side power switch?

John11513

Part Number: LM5050-1
Other Parts Discussed in Thread: LM5060

Hi,

As you know LM5050 can be used to drive a high side N-MOSFET on/off. I am wondered if it is possible to implement a high side power switch with two serial N-MOSFET and a LM5050-1/2? (features similar to Maxim's MAX1614).

Thank you,

John

over 6 years ago

0 Brian Daugherty over 6 years ago

TI__Expert 5940 points

John,

The LM5050 isn't straight forward for B2B FET use because of the zener from IN to GATE. Because of this diode, you cannot turn off the B2B FETs like you can with a single FET. You need to use the attached circuit.

Brian

LM5050 b2b FET Solution_A.pdf

0 John11513 over 6 years ago in reply to Brian Daugherty

TI__Expert 5360 points

Thank you for your answer. I will have customer study this solution.

John

0 John11513 over 6 years ago in reply to Brian Daugherty

TI__Expert 5360 points

Hi Brian,

Do you think LM5060 can be used in this way: driving B2B nFET to act as a high side power switch.

Thank you,
John

0 Brian Daugherty over 6 years ago in reply to John11513

TI__Expert 5940 points

John,

See fig 41 (recommended instead of fig 39) in the DS. The LM5060 can be used with B2B FETs, provide inrush protection, ov/uv. It isn't the best for current protection with only a timeout so it isn't used where Current Limit/Short Circuit protection is a must.

Brian

Power management

Power management forum

LM5050-1: Can this part be used to implement a N-MOSFET based high side power switch?