Voltage at VOUT in shutdown mode

Hello Tonyuche,

thank you for your response. Could you please clarify which components need to be desoldered in order to apply an external negative voltage?

Would removing D1 and R1 be sufficient, or would you also recommend desoldering L1A/L1B and/or C6?

Hi Tonyuche,

please change the salutation in your last reply from Feb 18, 2026 12:36 AM to my community name MaBo03 and use this in future replies. Thanks.

I use the LT8333 to power my system with a negative voltage Vout.

For laboratory tests, I would like to apply the negative voltage Vout into the system via a negative external power supply and not from the LT8333 circuit (see picture in first post). For example, to measure the system current consumption or test other negative voltages, without having to reconfigure the feedback resistors or inductors of the LT8333 circuit.

To avoid damaging the LT8333 with the reverse voltage injection, I could desolder components to isolate the circuit from the rest of the system for testing purposes.

Thanks,

MaBo03

Hi Tonyuche,

thanks for your reply.

On my PCB, it would be easier to desolder C6 instead of L1A. Would desoldering C6 also be a valid option to isolate the IC from the rest of the system?

In addition, to further protect the IC from unintentional activation during laboratory operation, I am planning to connect SS to GND as well as EN/UVLO to GND. Would SS to GND additionally prevent the output of the LT8333 from being switched on?

Thanks,

MaBo03