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I know 2 application of bootstrap:
1.mos gate driver for switched mode power supplies which drives high side switches (MOSFET or IGBT). they are usually fabricated in special HV proccess.
2.driving high swing NMOS transistors in switched cap ckts like sigma delta modulators or pipelined A/D.
what is your application?
what do u mean by hot switching?
another switchmode trick called bootstrapping is when you run the smps off the output, usually 5v switched down from 12-24. in order to get the smps to start up, it has the top gate on in shutdown or power down. Once enough voltage flows to bring the part out of undervoltage lockout it starts to PWM normally.
but bootstrapping to prevent hot switching? sounds like a hotswap configuration that also allows the output to charge a little, but that is the definition of hot switching so it seems unlikey as a prevention method.
due to supply voltage srinkage the desired range of operation of both nmod and transmission gate is drastically reducing. And in case of switch capacitor circuit one will see that the switch are not operating properly across the full range of input voltage. there exist a dead zone over which the on resistance of the switch is huge and varies by large amount.
Thsi varioation of switch resistance with input voltage is very annoying and leed to harmonic distortion.
So to avoide this the gate voltage of the switch is bottstap to the input signal so that Vgs across the transistor is allways VDD in on case.
Bootstrapping is typically used to decrease the Ron of the mos.
Typically ,one would go for this technique at low supplies (1.8V or less ),where one cannot afford for large area to decrease the on resistance of the switch .Increasing the area would lead to increase in parasitics which would kill your settling time .So one goes for increase in gate voltage to decrease Ron .
Ideally one want to make Ron independent of the input voltage .
Hot Switching ??? Guess that you are talking of Bootstrap in high speed circuits .
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