IR2110 with charge pump

[Aamir_Sheikh]

I am trying to run IR2110 with a charge pump, here is the schematic.

after making the circuit, the voltages on VB are 12.53, on VS are 12.13, when there is no signal on hin and lin, when i give a high signal on opto coupler connected to hin the voltage on hin is 4.63, but ho does not change, neither does VB or VS, is something wrong with my design?

 

[FvM]

1. The charge pump circuit can't work for this application. There must be no DC path from low side to Vs/Vb connected circuit.
2. Charge pump coupling capacitors are loading the bridge output and must be respectively small. It may be necessary to protect the generator (555 in this case) against switching spikes.

 

[Aamir_Sheikh]

1. The charge pump circuit can't work for this application. There must be no DC path from low side to Vs/Vb connected circuit.
2. Charge pump coupling capacitors are loading the bridge output and must be respectively small. It may be necessary to protect the generator (555 in this case) against switching spikes.

Thanks For replying
i do not understand, what DC path? and how small should be the coupling capacitors?

i based my design on this appnote
www.ti.com/lit/an/slva444/slva444.pdf‎

 

[FvM]

O.K. this is a charge pump with some restrictions. It doesn't generate a voltage above Vs rather than a voltage above COM respectively buck converter Vout. It doesn't work without a connected load. Vbs must be above UVLO threshold but below maximum Vgs and Vbs rating.

Depends on the intended operation (e.g. half-bridge load and output voltage) if it works at all.