My LT1054L circuit is not operating. Vref is at approx 2.5V and the FB pin is above 2V, Vcc and GND are connected but the output voltage is not going negative.
Will a large inductance (100uH) with low DCR (0.083 ohms) at the Vin pin (5V = Vin), which has a 22uF low ESR tantalum cap as Cin, cause the part to be damaged?
I ask because when I simulate my circuit, there are considerable voltage spikes at the Vin pin when the part starts up and these spikes increase with higher Cin.
Bringing down Cin to 1uF keeps these transients to about 12V but that could still damage the LT1054L which is only rated for 7V.
I could try reducing my Cin to 1uF or so, but I'd like to understand if I need to change my entire topology and do the inductive filtering downstream rather than trying to inductively isolate the LT1054L power. Also, I need to know if I should be ordering more parts, because I've blown the ones I have. (I will check the CAP+ and CAP- pins today, but if they turn out to be operative, I'm not sure if the part is still good--I don't know the exact operation failure that would occur from overvoltage spikes.)
The circuit always simulates fine and gives me pretty much the expected output (-Vout is not quite the calculated value).
It is only in the real world that things are going wrong.