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Any way to change a linear DC voltage to a x^2 response?

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David Hess:

--- Quote from: T3sl4co1l on November 14, 2019, 12:39:34 pm ---2d. PWM multiplier.  Create a linear PWM generator (can use a 555 with current sources to make linear ramps, then a comparator to slice the triangle wave into PWM), and drive an analog switch between 0V and VREF.  VREF is the same input signal setting PWM.  Filter the result.  Voila: you've got VREF*VREF.  This is a 1- or 2-quadrant multiplier depending on what kind of analog switch you've used, or if you cancel out offsets or not.  Downsides: not terrific accuracy (dominated by messy switching edges), slow (bandwidth and delay limited by PWM frequency and output ripple).
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The LTC1043 datasheet shows a charge balancing variation of that idea using two operational amplifiers and an LTC1043 dual switched capacitor building block.  One input controls the frequency via a charge balancing voltage-to-frequency converter and the other input controls the amount of charge transferred to the output per cycle.  Bandwidth is low but accuracy is excellent and no special provisions or parts for temperature compensation are required.

edavid:

--- Quote from: K3mHtH on November 14, 2019, 06:45:30 am ---Thanks, but I should have specified that I"d like to keep the design analog.

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Why?

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