Can anyone please explain me in detail the analog switch? Few days ago, someone asked me a question that "name the device which is used to switch the analog signal". I think the answer to this question is analog switch. But please explain me in detail the analog switch, i am unable to understand it from definition on net. Thanks
An analog switch is an IC that passes or blocks an analog or digital signal and is controlled by a logic input voltage.
Look at the datasheets for CD4016, CD4066, CD4051, CD4052, CAD4053, CD4067, CD4097 and their HC sisters.
An electrical analog switch works like a relay - however, not mechanical but electrical.
In principle, it is like a resistor between two nodes - input and output - which can be operated between two extreme values: Very large (megohm range, switch "open") and veryx small (milliohm range, switch closed).
Such a switch can be realized with a FET (operated it the ohmic region) or with complementary MOSFETs (CMOS).
An electronic analog (or analogue for those speaking the King's English) switch operates similar to a mechanical relay expect generally the OFF resistance is not as high and the ON resistance is not as low.
Also electronic switches do no typically provide electrical isolation between the control signal and the signal being controlled.