how to design DICKSON charge pump.

[wonbef]

hi, all,

now i design a DICKSON charge pump with 0.6-um low voltage DPDM CMOS process, input dc voltage is +3V, and i hope the output is -3V. but the output voltage is only about -1.2V. why? Need your helps!


best regards,

 

[keith1200rs]

I think you will have to post your circuit. This is a useful comparison of various circuit topologies.

www.ocf.berkeley.edu/~eng/classes/EE290cPresentation.ppt

Keith.

 

[dick_freebird]

If you used diodes, you lose 0.7V per stage and that leaves
nothing much after 4, and poor conversion ratio even
earlier. A synchronous-switched charge pump will do better.
Parallel-fed is way better than series fed too.

Be sure there isn't something dumb like a well diode clamping
the output voltage. If you burn a lot of current at open output,
might check that more carefully.