Category: FET BIASING

Biasing FET Switching Circuits

Biasing FET Switching Circuits: JFET Switching – A Biasing FET Switching Circuits is normally in an off state with zero drain current, or in an on state with a very small drain-source voltage. When the FET is off, there is a drain-source leakage current so small that it can almost always be neglected. When the […]

MOSFET Biasing Circuits

MOSFET Biasing Circuits: DE-MOSFET Bias Circuits – DE-MOSFET bias circuits are similar to JFET bias circuits. Any of the FET bias circuits already discussed can be used to produce a negative VGS level for an n-channel MOSFET Biasing Circuits, or a positive VGS for a p-channel device. In this case, both devices would be operating in […]

Universal Transfer Characteristics for FET

Universal Transfer Characteristics for FET: A Universal Transfer Characteristics for FET is simply a transfer characteristic plotted with IDSS = 1 and VP = 1. Then, instead of the scales being calibrated in milliamps and volts, they are marked as the ratios ID/IDSS and VGS/VP. To construct the Universal Transfer Characteristics for FET, Eq. 9-1 is rewritten, Now, by substituting […]

JFET Biasing Circuits

JFET Biasing Circuits: Use of Plus/Minus Supplies – When plus/minus supply voltages are to be used with a JFET Biasing Circuits, the gate terminal is usually grounded via RG, as illustrated in Fig. 10-40(a). In this case, the circuit is essentially a voltage divider bias circuit with the gate bias voltage equal to the level […]

JFET Bias Circuit Design

JFET Bias Circuit Design: Design Approach – Design of JFET Bias Circuit Design is just as simple as design of BJT bias circuits. One major difference is that FET circuit design normally uses a graphical approach involving the drawing of a bias line on the device transfer characteristics, as in the case of FET circuit […]

JFET Bias Circuit Troubleshooting

JFET Bias Circuit Troubleshooting: Voltage Measurement – JFET Bias Circuit Troubleshooting are similar to those for BJT bias circuits. The major difference is that there is only one junction in the FET (the gate-channel junction) that might become short-circuited or open-circuited. To determine if the circuit is functioning correctly, the FET terminal voltages should all […]