Due to its construction if offers very high input resistance about 10 10 to 10 When gate i. This will result into depletion of majority carriers i.
Hence the curve similarto JFET is obtained as shown in the figure As shown in the symbol here gate is insulated from the channel. Here continuous channel does not exist from source to drain.
difference between Depletion MOSFET vs Enhancement MOSFET
Hence no current flows at zero gate voltage. Symbol depicts broken channel between 'S' to 'D' terminals.
Depletion Type MOSFET: What is it? (Worked Example)
When positive voltage is applied to the gate, it will induce a channel by flowing minority carriers i. As shown in the figure-4 minimum threshold voltage is needed for the flow of drain current to start.
This type of FET is ideal for switching application. This is due to the fact that no gate voltage is needed to keep the device in 'off' state.
Moreover the device can be powered ON with the application of same polarity as drain terminal.