On the topic of MOSFETS (again).......sorry......
I didn't want to ask this question in the other current threads as it would just confuse the situation with talk of the different ways you can control a MOSFET.
So here is my situation.... I want to control an N-channel mosfet (IRL3803) on the high side of a 12V power supply. I will be dimming a LOT of LEDs with PWM.
I want to do it properly to minimise heat dissipation so I will be going for a dedicated N-Channel MOSFET IC from International Rectifier. I have chosen the IRS2001.
The IRS2001 has two outputs, one for a high side N-channel fet and another for a low side fet.
My understanding is that for the fet to turn on while in the high side, its gate has to be supplied with a voltage that is 10V higher than the power supply (in this case its a 12V power supply so I need 22v on the gate)
Stop me if this is incorrect....
Now my question is, looking at the first diagram on page one of the datasheet attached, how on earth can the IRS2001 generate a voltage greater than VCC without actually being connected to the high side voltage????? There is no talk of a charge pump in the description and in any case it does not know what potential the fet is connected to...
I didn't want to ask this question in the other current threads as it would just confuse the situation with talk of the different ways you can control a MOSFET.
So here is my situation.... I want to control an N-channel mosfet (IRL3803) on the high side of a 12V power supply. I will be dimming a LOT of LEDs with PWM.
I want to do it properly to minimise heat dissipation so I will be going for a dedicated N-Channel MOSFET IC from International Rectifier. I have chosen the IRS2001.
The IRS2001 has two outputs, one for a high side N-channel fet and another for a low side fet.
My understanding is that for the fet to turn on while in the high side, its gate has to be supplied with a voltage that is 10V higher than the power supply (in this case its a 12V power supply so I need 22v on the gate)
Stop me if this is incorrect....
Now my question is, looking at the first diagram on page one of the datasheet attached, how on earth can the IRS2001 generate a voltage greater than VCC without actually being connected to the high side voltage????? There is no talk of a charge pump in the description and in any case it does not know what potential the fet is connected to...
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