Why do we use gate driver in some power amplifier circuits

[analog_ocean]

Hi all..am new here

HI,
I want to know why we use the gate driver in some some power amplifier circuits.what is the actual reason.

Tell me if you know

 

[INS-ANI]

Hi all..am new here

Even i was having same problem in second year of my engineering, hence i wil try to explain u a bit what i have understood last year..

gate drive (in this case is a bidirectional current source, which can control the limits for gate current, which in turn can control the slew rate of power amplifier.

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[Aya2002]

Hi all..am new here

this is correct INS-ANI as i remember

 

[joker12]

Re: Hi all..am new here

Just wondering, are you talking about MOSFETs or what?

 

[python_k]

Hi all..am new here

the most important characteristic is that gate driver like mosfet has no current throgh it

 

[avi_e-]

Re: Hi all..am new here

Hi,

All power semiconductor devices need gate pulses to get turned ON.
There r circuits which trigger pulses to those gates, these ve to be controlled to maintain the slew rate v desire. Then some power semiconductor devices such as SCR can be switched ON by a gate pulse nd cannot be switched OFF by any means other than itself attaining zero current condition. If these like devices r used then v need to control everything. So, Gate drivers are used in amplifiers.


Regards,
Avinash.S.

 

[GroovyGuru]

Re: Hi all..am new here

INS-ANI had the best info so far the gate driver does 2 importent things it turns the driver on/off if it's a switch or controls how on if it's linear [never off], the 2nd job it does is to prevent changes in gate/drain voltage from affecting gate/source voltage since a power fet looks like 2 capacitors in series bypassed by a wildly variable current leak.
BTW for junction transistor outputs this circuits a "pre-driver".