How can a MOSFET be used as a resistor?
A MOSFET can easily be used as a variable resistor. The minimum resistance you need and the RDS(on) of the MOSFET chosen. The MOSFET’s behavior in the linear region though it is similar for almost all the MOSFETs.
In which region JFET acts as a resistor?
triode region
In the triode region, the JFET acts like a resistor, however, in the saturation region it behaves like a constant-current source.
Is a MOSFET a resistor?
Misconception: Design a MOSFET to use the saturation region. MOSFETs and BJTs define their saturation region differently! A MOSFET acts as a variable resistor in the linear region and as a current source in the saturation region. Unlike a BJT, to use a MOSFET as a switch, you need to operate within the linear region.
Can we use BJT as a resistor?
Hence, the BJT cannot be used as avoltage-controlled resistor.
Can I use a MOSFET as a diode?
To minimize this forward drop you can configure a MOSFET as an ideal diode, which has a very low drop in the forward direction (equal to the current times the MOSFET’s ON resistance) while blocking the current in the reverse direction. (MOSFETs conduct equally well in either direction when on.)
Can we use MOSFET as a diode?
A simple N-channel MOSFET can be used as a diode, Switch and Active resistor.
Can FET be used as a resistor?
It is due to the fact that in this region drain-to-source resistance RDS can be controlled by varying the bias voltage VGS. In such applications the FET is also referred to as a voltage-variable resistor or volatile dependent resistor.
Does a MOSFET reduce voltage?
MOSFET: When the gate voltage is large with respect the the threshold voltage Vth, the voltage drop from drain to source is linearly dependent on current (for small voltages << Vth of the MOSFET), so it behaves like a resistor.
Do MOSFETs have a minimum voltage?
1) a Vgs between 3-5V will turn on the MOSFET. 2) Vgs must be greater than 5V, since that is the minimum voltage required to turn on the MOSFET.
Can I use a transistor as a resistor?
Of course the transistor can be used as a resistor that is exactly what it is – a controllable resistance. The resistance is between the collector and emitter – we control it by applying suitable signals to the base. However there is no requirement for that resistance to be high or low, it is up to us to set its value.
Why BJT is current control device?
A BJT is a current controlled device because its output characteristics are determined by the input current. A FET is voltage controlled device because its output characteristics are determined by the Field which depends on Voltage applied.
Can a FET be used as a voltage controlled resistor?
We consider the use of a n-channel FET as a voltage controlled resistor where the resistance between the drain and source is controlled by the gate-source voltage. There are two distinct regions. In the Ohmic region1, the drain-to-source current, I. DS, depends on the gate-to-source voltage, V.
How is the linear resistance of a FET set?
The voltage controlled “linear” resistance is then set by the Vgs voltage. For example, if Vp = -1.5 volts, Vgs = – 1.0 volt, and I DSS = 0.005 A = 5 mA, then From equation (5), if we set Vgs = Vp , then the drain to source resistance will be infinite (e.g., open circuit):
How is the field effect transistor a voltage controlled resistor?
The field effect transistor as a voltage controlled resistor. We consider the use of a n-channel FET as a voltage controlled resistor where the resistance between the drain and source is controlled by the gate-source voltage. There are two distinct regions. In the Ohmic region1, the drain-to-source current, I.
How is a FET different from a bipolar transistor?
As the field effect transistor is a voltage operated device rather than a current device like the bipolar transistor, this means that some aspects of the circuit are very different: the bias arrangements in particular. However electronic circuit design with FETs is relatively easy – it is just a bit different to that using bipolar transistors.