An oscilloscope is an electronic instrument that presents a graphical display of its input voltage as a function of time. It is important to note that oscilloscopes only measure voltages not currents or resistances however … Read more
A phase-locked loop (PLL) is a form of a servo system which consists of a phase detector, low-pass filter and voltage controlled-oscillator (VCO) as illustrated in the block diagram below. The phase detector compares … Read more
Linear ICs (LICs) also referred to as analog ICs are characterized by inputs and outputs that can take a continuous range of values. In addition, the outputs are generally proportional to the inputs. On the other hand, Digital ICs contain … Read more
The operation of a typical AM audio frequency signal is illustrated in the Figure 1.0 where vin is the modulated signal that is shown Figure 1.1.
A typical amplitude modulated signal that is fed … Read more
When light strikes a semiconductor p-n junction, its energy is absorbed by electrons. Electrons and holes generated by light in the p-n junction are swept by the junction electrical field. Consequently, the current flows through the junction.
The figure below … Read more
Laser diodes are PN junction devices under a forward bias. LASER is an acronym for Light Amplification by Stimulated Emission of Radiation.
The laser diode structure can be divided into two categories:… Read more
Because of the very high input gate resistance of MOSFETs, MOSFET’s fast switching speeds, and the ease at which they can be driven makes them ideal to interface with op-amps or standard logic gates. Nevertheless, care must be taken to … Read more
The Metal oxide semiconductor FET (MOSFET) also known as the insulated-gate FET (IGFET) is similar to JFET but exhibits even larger resistive input impedance due to the thin layer of silicon dioxide that is used to insulate the gate from … Read more
The bipolar transistor has several disadvantages: it has low input impedance because of forward biased emitter junction, it has small high-frequency gain, it has considerable noise level and it is non-linear when |VCE| < 2V. Although low input … Read more
