Voltmeter design Build a MOSFET voltmeter in LT pice The MOS

Voltmeter design: Build a MOSFET voltmeter in LT pice. The MOSFETs in the voltmeter act as switches. To turn on the MOSFET assume Vg = 2.1 Vdc when it begins to switch on. Design the Rd1, Rd2, and Rd3 values, such that the maximum drain current when the MOSFET in on is 8mA for Vdd = 10Vdc VdS_SAT = 100mV. Design the input voltage divider resistors values such that M1 Vout1 turns on at approximately Vin = 6V, M2 Vout2 turns on at approximately Vin = 10V, and M3 Vout3 turns on at approximately Vin = 14V. Choose input resistors (Rg1, Rg2), (Rg3, Rg4) and. (Rg5, Rg6) values that are in the 10k Ohm to 150k Ohm range. Tip: Remember that you can split this circuit into three circuits that are similar to the first stage of the voltmeter. To find the voltage divider resistors (Rg1, Rg2), (Rg3, Rg4), and (Rg5, Rg6) you can create three circuits when Vin= 6V, Vin=10V, and Vin=14V. The calculation steps will be identical to the first voltmeter, but the input voltage (Vin) will be the only difference.

Solution

It is also named common- emitter amplifier because the emitter of the transistor is common to both the input circuit and output circuit. The input signal is applied across the ground and the base circuit of the transistor. The output signal appears across ground and the collector of the transistor. Since the emitter is connected to the ground, it is common to signals, input and output.

The common- emitter circuit is the most widely used of junction, transistor amplifiers. As compared with the common- base connection, it has higher input impedance and lower output impedance. A single power supply is easily used for biasing. In addition, higher voltage and power gains are usually obtained for common- emitter (CE) operation.

Current gain in the common emitter circuit is obtained from the base and the collector circuit currents. Because a very small change in base current produces a large change in collector current, the current gain () is always greater than unity for the common-emitter circuit, a typical value is ab.