Untitled. Guitar signal boosters have been a hot item on guitarists' lists ever since Johnny Dallas cooked up the primordial Dallas Rangemaster and set it loose on an unsuspecting world. While the Rangemaster was a great advance in its day, and more than made up for the shortcomings of the typical low-output pickup of the time, guitarists ever since have chased boxes that could push their amps just a little harder. For a more in-depth read on the Dallas Rangemaster, see Rangemaster - the European Secret Weapon. The next most venerable box in this line is the ElectroHarmonix LPB-1 (Linear Power Booster 1), Mike Matthews' single-transistor entry into the booster sweepstakes.
The LPB-1 was advertised as making your amp sound louder - and perhaps it did, using up whatever headroom the amp had left and driving the bejeezus out of the input. The LPB-1 suffered from noise and the limitations of its heritage as a bipolar silicon NPN transistor gain stage. We'll ignore Rbias, Cin and Cout for now. Suitable small MOSFET - Page 2. MOSFET Amplifier. Next: CMOS Digital Logic Circuits Up: ch4 Previous: Metal-Oxide-Semiconductor Field-Effect Transistors Assume in the circuit above and the transistor is in saturation region, i.e., , then we have The second equation relates the output to the input , as shown by the red segment of the curve in the plot above.
Which can be solved for to get: It can be seen that when the transistor is in saturation mode the slope of the curve (red) indicates the ratio between input and output . Example: Assume . Then we have and the voltage gain is a function of the input This nonlinear equation can be represented by the table below: In particular, when the input increases from to , the output decreases from , with a gain . In summary, we see that When the transistor is in saturation mode, the circuit behaves as a voltage amplifier.
Next we consider a MOSFET circuit with sinusoidal input. And a sinusoidal input . , the input voltage varies between 1.4V and 1.6V. In particular, corresponding to , the output voltage , and and . Ch06.pdf (application/pdf Object)