Analog switches

The breadboard pulse load waveform (from 300 mA to 5 A) is shown in Fig. 5.16. The IsSpice simulation results are shown in Fig. 5.17. Micro-Cap and PSpice results are shown in Figs. 5.18 and 5.19. In Figs. 5.15, 5.16, 5.17, and 5.19, the top waveform is the output of the comparator and the bottom waveform is the output of the analog switch (which would then be connected to the electronic load power circuit, such as that shown earlier in this chapter.)... 

A logic part responsible for selection of signals to be processed, control of analog switches, and interfacing time delay units... 

Figure 1 Schematic of EP sample and experimental setup. G-P, galvanostat-potentiostat A-S, analog switch W,C,R, working, counter-, and reference electrodes, respectively.

High-temperature circuit leak. The basic peak/bottom hold circuit consists of an analog switch utilizing MOS transistors, a capacitor, and an op-amp. The transistors comprising the analog switch will leak at the pn junctions at high tem-... 

Electromechanical analog switches exhibit some very desirable characteristics. They have essentially zero resistance when the contacts are closed and infinite resistance when they are open. They can handle a range of many orders of magnitude of voltage and current of either polarity. They also have, as might be expected, some undesirable characteristics. First, the contacts bounce whenever they are opened or closed. This can result in noise that must be filtered out. Mercury-wetted contacts can lessen bounce noise, but do not eliminate it. Second, electromechanical switches are rather slow in switching the faster ones take 1 msec or so to open or close. 

Electronic analog switches also have some shortcomings. They have finite on and off resistances. JFETs usually have the smaller on or closed resistance, some types as low as 1 or so. MOSFETs, on the other hand, have the higher off or open resistance, typically of the order of 10 Q. In other words, FET switches are not ideal switches, but rather electronically variable resistors. 

The resistors labeled Rm represent parasitic resistances of the analog switches used in the multiplexer. These resistances can range in value from 35 to several Idlohms. 

Designing with Analog Switches, Steve Moore... 

To date, many more modes of switching operations for EEC cells have been developed, such as the deformable helix effect analog switching,the Sony-mode ... 

Therefore, when you open an analog Instrument, you will see inside discrete components, analog integrated circuits, like operational amplifiers, comparators, analog switches, and, more rarely, multipliers and possibly some digital integrated circuits. 

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