There is a certain node in my circuit at which I want to limit level of voltage. The voltage at the node is pulled up by a resistor with an amount of about 1MΩ. I want to use a transistor to ground this node if excess voltage is delivered.
But I don't want to pull-down the voltage at normal operation (i.e.; the node voltage is below upper limit).
For this purpose I need a transistor which has an off-state resistan much higher than 1MΩ.
Which transistor type has the highest possible off-state resistance? BJT, FET or MOSFET?
Can you suggest me a part number please, if you can?