N MOSFET switching control circuit design

[Chandra Sekar]

Hai to all
      I would like to design a precharging circuit with 8 parallel n channel MOSFET on 12v each MOSFET capacitance is 120nc ,but my system voltage is 80v .to control inrush current from battery

[nosnowfall]

not sure what you mean by "12V on each MOSFET" or which capacitance is 120nC?

But for inrush limiting, I've seen a hybrid PWM/PTC design used for 72V lead-acid batteries. Basically have some 100s of Ohms with a PTC, and bypass that with MOSFET switches. You can PWM the MOSFETs to adjust average current, eventually turning them on 100% at full charge.

[makebit]

Yes , and with inrush...you can also just have a plain inrush resistor and short it out with the FETs.
But either way, make sure your system is not pulling load current at the time  that the inrush is flowing through the inrush resistor....so disable the circuit until the inrush event is over, and only enable the cct when the
inrush relay (or whatever) is shorting out the inrush resistor.