@felipe_lopez Hi, You have many ways to apply the -32V (and on this case the exact value is not relevant, important is not go above the value present on datasheet of IC). We can use a converter DC/DC like the B0524S-2W (seller at web by near of 1€) associated in serial with a B0512S-2W which give to us the 36V. Note the letter "S", this is very important, means the converter is isolated from primary block to the secondary block. The value of amperage required is very low, milliamperes! The important is the 3 power sources be total independent. You can also make use for example the regulator from family's 7924, this already give -24 output, but also can use the 7824 and on this case the output is connected to our GND or 0V which result in GND of regulator (LDO) be our -24V, the importance of independency of power sources is exactly to allow this kind of connections. Please look around my channel you have many examples how power up drivers the VFD's with transformers, converters DC/DC, association in serial of DC/DC converters. If you don't find help on the videos examples, let me know and I will try explain this matter better, ok I know this is a little confuse but I hope this help!