can opamp work this way ??


by XuFyaN
Tags: opamp, work
XuFyaN
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#1
Aug30-11, 01:01 PM
P: 50
can opamp work this way ..?

when i input 2volts the output is 4volts , when i input 5 volts the output is 25 volts

in simple words can opamp takes the square of input signals ??

is it possible ? i know how it work as differentiator, integrator, Summing amp but what about squaring ?
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Studiot
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#2
Aug30-11, 01:34 PM
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To obtain squares and square roots you need a four quadrant multiplier, such as the MC 1494.

There is an analog solution using the square law characteritic of diodes or FETs but they are tricky to set up.
XuFyaN
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#3
Aug30-11, 01:37 PM
P: 50
can you please help about using diodes for squaring and square rooting ? what technique we use for squaring ?

like if we Apply n volts the output must b n*n
or simply sum of n times ,
like if we apply 5 volts the output must be 5+5+5+5+5

Bob S
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#4
Aug30-11, 03:48 PM
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can opamp work this way ??


Review the circuit in

http://www.analog.com/library/analog...f/pdf/19_1.pdf

The transistors are working in essentially the transdiode configuration, because they give superior diode lograrithmic performance than real diodes. Look at the equations Eq (1) thru (6). The (kT/q) log function is the ideal diode I-V response.

Bob S
berkeman
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Aug30-11, 06:38 PM
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Quote Quote by XuFyaN View Post
can opamp work this way ..?

when i input 2volts the output is 4volts , when i input 5 volts the output is 25 volts

in simple words can opamp takes the square of input signals ??

is it possible ? i know how it work as differentiator, integrator, Summing amp but what about squaring ?
Are you constrained to using opamps? Can you use an ADC + Microcontroller + DAC instead?


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