# Analog division, current conveyors and SPICE

Started by August 15, 2014
```Could some analog/SPICE guru please help ?
I am running SPICE simulations on current
conveyors, focusing analog computation.
Specifically, I am examining in detail
analog division. I am referring to Sedra
and Smith's 1970 paper.

Given that a negative impedance converter
shifts the phase of the input signal by 180
degrees, what would be the effect of analog
division of one signal by another ?
Specifically how should the output look like?
For example, if s11, s12, s13, s14, x15, ...
and s21, s22, s23, s24, ... etc., are
respectively the input signal values, should
the output signal be simply s11/s12, x12/s22
and so on ?
Any hints, suggestions would be of immense

```
```On Thu, 14 Aug 2014 21:52:21 -0700 (PDT), dakupoto@gmail.com wrote:

>I am running SPICE simulations on current
>conveyors, focusing analog computation.
>Specifically, I am examining in detail
>analog division. I am referring to Sedra
>and Smith's 1970 paper.

Current conveyors are just a hokey name invention by PhD's to make
ideal current mirrors into something magical >:-}

>
>Given that a negative impedance converter
>shifts the phase of the input signal by 180
>degrees, what would be the effect of analog
>division of one signal by another ?
>Specifically how should the output look like?
>For example, if s11, s12, s13, s14, x15, ...
>and s21, s22, s23, s24, ... etc., are
>respectively the input signal values, should
>the output signal be simply s11/s12, x12/s22
>and so on ?
>Any hints, suggestions would be of immense
>
>
>

What are you actually trying to accomplish?

...Jim Thompson
--
| James E.Thompson                                 |    mens     |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

I love to cook with wine.     Sometimes I even put it in the food.
```
```On 2014-08-15, dakupoto@gmail.com <dakupoto@gmail.com> wrote:
> I am running SPICE simulations on current
> conveyors, focusing analog computation.
> Specifically, I am examining in detail
> analog division. I am referring to Sedra
> and Smith's 1970 paper.
>
> Given that a negative impedance converter
> shifts the phase of the input signal by 180
> degrees, what would be the effect of analog
> division of one signal by another ?

division by zero.

> Specifically how should the output look like?

real world or idealised?

> Any hints, suggestions would be of immense

don't go there.

--
umop apisdn

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
```
```On Friday, August 15, 2014 1:02:01 PM UTC-4, Jim Thompson wrote:
> On Thu, 14 Aug 2014 21:52:21 -0700 (PDT), dakupoto@gmail.com wrote:
>
>
>
>
> >I am running SPICE simulations on current
>
> >conveyors, focusing analog computation.
>
> >Specifically, I am examining in detail
>
> >analog division. I am referring to Sedra
>
> >and Smith's 1970 paper.
>
>
>
> Current conveyors are just a hokey name invention by PhD's to make
>
> ideal current mirrors into something magical >:-}
>
>
>
> >
>
> >Given that a negative impedance converter
>
> >shifts the phase of the input signal by 180
>
> >degrees, what would be the effect of analog
>
> >division of one signal by another ?
>
> >Specifically how should the output look like?
>
> >For example, if s11, s12, s13, s14, x15, ...
>
> >and s21, s22, s23, s24, ... etc., are
>
> >respectively the input signal values, should
>
> >the output signal be simply s11/s12, x12/s22
>
> >and so on ?
>
> >Any hints, suggestions would be of immense
>
>
> >
>
> >
>
> >
>
>
>
> What are you actually trying to accomplish?
>
>
>
>                                         ...Jim Thompson
>
> --
>
> | James E.Thompson                                 |    mens     |
>
>
> | Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
>
> | San Tan Valley, AZ 85142     Skype: skypeanalog  |             |
>
> | Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
>
> | E-mail Icon at http://www.analog-innovations.com |    1962     |
>
>
>
> I love to cook with wine.     Sometimes I even put it in the food.

Current conveyors are used in
active impedance matching, also
in some instrumentation amplifiers.
and filters. Some have claimed
that they may be used in analog
computation. I am trying to
simulate/understand signal division
and multiplication with current
conveyors. Right now it is all
one quadrant, but later I intend
to push to more quadrant operation.
```
```On Fri, 15 Aug 2014 22:47:37 -0700 (PDT), dakupoto@gmail.com wrote:

>On Friday, August 15, 2014 1:02:01 PM UTC-4, Jim Thompson wrote:
>> On Thu, 14 Aug 2014 21:52:21 -0700 (PDT), dakupoto@gmail.com wrote:
>>
>>
>>
>>
>> >I am running SPICE simulations on current
>>
>> >conveyors, focusing analog computation.
>>
>> >Specifically, I am examining in detail
>>
>> >analog division. I am referring to Sedra
>>
>> >and Smith's 1970 paper.
>>
>>
>>
>> Current conveyors are just a hokey name invention by PhD's to make
>>
>> ideal current mirrors into something magical >:-}
>>
>>
>>
>> >
>>
>> >Given that a negative impedance converter
>>
>> >shifts the phase of the input signal by 180
>>
>> >degrees, what would be the effect of analog
>>
>> >division of one signal by another ?
>>
>> >Specifically how should the output look like?
>>
>> >For example, if s11, s12, s13, s14, x15, ...
>>
>> >and s21, s22, s23, s24, ... etc., are
>>
>> >respectively the input signal values, should
>>
>> >the output signal be simply s11/s12, x12/s22
>>
>> >and so on ?
>>
>> >Any hints, suggestions would be of immense
>>
>>
>> >
>>
>> >
>>
>> >
>>
>>
>>
>> What are you actually trying to accomplish?
>>
>>
>>
>>                                         ...Jim Thompson
>>
>> --
>>
>> | James E.Thompson                                 |    mens     |
>>
>>
>> | Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
>>
>> | San Tan Valley, AZ 85142     Skype: skypeanalog  |             |
>>
>> | Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
>>
>> | E-mail Icon at http://www.analog-innovations.com |    1962     |
>>
>>
>>
>> I love to cook with wine.     Sometimes I even put it in the food.
>
>Current conveyors are used in
>active impedance matching, also
>in some instrumentation amplifiers.
>and filters. Some have claimed
>that they may be used in analog
>computation. I am trying to
>simulate/understand signal division
>and multiplication with current
>conveyors. Right now it is all
>one quadrant, but later I intend
>to push to more quadrant operation.

The are 8 items on the S.E.D/Schematics Page of my website devoted to
"gyrators"... analyzing those _by_hand_ will provide some insight.

...Jim Thompson
--
| James E.Thompson                                 |    mens     |