I uses negative power output IC LT1931ES5.
Previously, the device had no problems.
But, The LT1931 purchased this time can not a voltage trigger.
As soon as the negative voltage is initially output, it drops to 0v.
I bought it an authorized agency..
Refer to the attached circuit. please reply... thank you...
- in ku park -
The schematic you posted appears normal, besides the value of the C105 capacitor. I would make sure the new parts you have are what they claim to be.
For further support you would need to provide further…
It was the capacity probleam of inductor. The capacity value of the ring coil was 330 uh. Thanks for your support....
The input capacitor, C105, seems too light in value. Increase the value to at least 2.2uF, then, try again.
I change input capacitor... but can't maintain voltage... The parts purchased in the past operate normally in this circuit. thank for your answer...
For further support you would need to provide further details, such as scope waveforms, pin voltages, etc..
Previously purchased parts also operate normally on the current board.
no1 : VIN no2 : SHDN no3 : NFB no4 : OUTPUT
this wareform is a photo of a person replacing only parts in the same circuit with LT1931A.
Thanks for the feedback!