Multiplier

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botthe.

Joined Feb 7, 2013
7
Hi! I have to implement a circuit to obtain an output, which is the product of two inputs. The inputs can vary between -3 to +3 with a max frequency of 10 kHz. Also, I am provided with supplies of (+) or (-) 5 V. I am not supposed to use any multiplier ICs. I thought of the log-antilog technique but it won't work as I have negative inputs. There was a circuit using MOSFETs in wikibooks but that again works only for positive voltages. There was another one using BJTs(transconductance) but again had a limitation of input voltage << 25 mV. Any suggestions?
 
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#12

Joined Nov 30, 2010
18,224
Hint: What is positive and what is negative are positive and negative compared to someplace. Change the "someplace". Change your frame of reference. Change the way you are thinking.
 

WBahn

Joined Mar 31, 2012
29,976
Hi! I have to implement a circuit to obtain an output, which is the product of two inputs. The inputs can vary between -3 to +3 with a max frequency of 10 kHz. Also, I am provided with supplies of (+) or (-) 5 V. I am not supposed to use any multiplier ICs. I thought of the log-antilog technique but it won't work as I have negative inputs. There was a circuit using MOSFETs in wikibooks but that again works only for positive voltages. There was another one using BJTs(transconductance) but again had a limitation of input voltage << 25 mV. Any suggestions?
So what is your circuit supposed to output when the two inputs are both at 3V?

Is this homework of some kind?
 
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