Table of Contents
Which transistor is more suitable for the current mirror circuit?
This current mirror circuit can be implemented with two MOSFET transistors. This circuit working is similar to the previously discussed mirror circuit. The current mirror circuit using MOSFETs is shown below.
How MOSFET can be used to operate as a current source and a current mirror?
MOSFET device function like this, the drain current reflects the function of the gate to source and drain to gate voltage. Due to this, the input current in the MOSFET M1, is mirrored to the drain current. In the image, the input current is provided by the bias resistor.
Which type of device is MOSFET?
The MOSFET (Metal Oxide Semiconductor Field Effect Transistor) transistor is a semiconductor device which is widely used for switching and amplifying electronic signals in the electronic devices. The MOSFET is a three terminal device such as source, gate, and drain.
Which current mirror circuit is used for the very low current *?
11.8 Widlar current source. A Widlar current source is a modification of the basic two-transistor current mirror that incorporates an emitter degeneration resistor for only the output transistor, enabling the current source to generate low currents using only moderate resistor values.
What is current mirror MOSFET?
A current mirror is a circuit designed to copy a current through one active device by controlling the current in another active device of a circuit, keeping the output current constant regardless of loading. The current mirror is used to provide bias currents and active loads to circuits.
What are the types of MOSFET devices available?
Explanation: MOSFET are of two types: enhancement and depletion type. Further, these are classified into n-type and p-type device. The depletion type is switched on without the application of gate bias voltage and the enhancement type is switched on with the application of gate voltage.
What is the difference between BJT and MOSFET?
The BJT current mirror operates by the same method as the MOSFET version, butwith a few key differences. First and foremost is the issue of base-drive: a current mirror supplying largeamounts of current throughout a circuit may result in unacceptable base currents.
What are the advantages of MOS current mirror over BJT current mirror?
A significant advantage of the MOS current mirror is the lack of base current induced error that BJT current mirrors suffer. There are methods to correct or compensate for the base current in BJT current mirrors which will be discussed in detail in later sections of this chapter.
How to implement current mirror circuit using MOSFET?
Current mirror circuit can be easily implemented using two MOSFET transistors. The working of the MOSFET current mirror circuit is similar as described in the previous transistor section. Consider the above current mirror circuit using MOSFET, the MOSFET transistor M1 is in the saturation region as the V DS ≤ V GS.
How do you use a bipolar junction transistor for current mirroring?
Bipolar junction transistors are widely used for current mirroring. The first trick to use bipolar junction transistor as a current mirror circuit is to construct an exponential voltage to current converter using the transistor.