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PSoC™ 4 Forum Discussions

AsRa_264661
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50 replies posted 25 replies posted 10 likes received

Hi All,

I'm using PSOC4 prototype kit.

When i check the resistance values between two analog pins. 300 Ohm is coming, any reason? ideal value should be zero or less than 10 Ohm right?

if i want to get zero Ohm what i need to do?  or any other products from cypress?

pastedImage_0.png

Thanks,

Ashok r

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1 Solution
Vasanth
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250 sign-ins 500 solutions authored First question asked

Hello Ashok,

In PSoC devices, when you interconnect GPIOs they are connected through the AMuX buses. Now there are switches involved in connecting the pins to the bus and there are bus routing resistance too. Even if the pins are physically close, the switch resistances are present. You can see the CYDWR -> Analog tab to get an idea of what I have said. Also if you want to get an approximate value of the resistance between different routes, you can use the ohm meter option in the CYDWR analog tab. Please see ohm meter in the Creator help section.

Best Regards,
Vasanth R S

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8 Replies
Vasanth
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250 sign-ins 500 solutions authored First question asked

Hello Ashok,

In PSoC devices, when you interconnect GPIOs they are connected through the AMuX buses. Now there are switches involved in connecting the pins to the bus and there are bus routing resistance too. Even if the pins are physically close, the switch resistances are present. You can see the CYDWR -> Analog tab to get an idea of what I have said. Also if you want to get an approximate value of the resistance between different routes, you can use the ohm meter option in the CYDWR analog tab. Please see ohm meter in the Creator help section.

Best Regards,
Vasanth R S

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Thanks VasanthR_91

I checked this Ohm meter but did not understand completely but i will. my question is , is there way to reduce the resistance value  further? because there are some cmos switches available which gives 10 Ohm or less then values.

If not possible with PSoC4 any other options? Analog processors or something.. from cypress

Thanks,

Ashok R

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Hi,

If you need those pins to be connected with very low resistance,

and all you need is acquire the voltage of the net

you may be able to connect them externally

and connect an analog input to monitor the voltage.

000-schematic.JPG

moto

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Hi Moto,

What does means? acquire the voltage of the net

the ultimate goal for me to bring the analog cmos switches in PSoC , example  using software i can short two pins of PSoC :

If( var ==1 )   P0.0 and P0.1 will be shorted (10 Ohm or less )   currently getting 300Ohm

Thanks,

Ashok r

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Dear Ashok-san,

I'm very sorry for my pointless reply.

Now what I can think of  within my knowledge is something like

000-schematic.JPG

But I wonder if this meet your requirement.

If what you wrote "short" means bi-directional propagation, this will not be take care of that.

Best Regards,

8-Apr-2019

Motoo Tanaka

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Hi  user_13463998​,

No problem!

Check my design here.. If i set AMux_1 Channel to 2,

AMux_1_FastSelect(2);

the PSoC pins, 1 and 2 will be shorted. when i measure the resistance I'm getting 300 Ohm. I want to reduce to less then 10 Ohm.

pastedImage_0.png

Thank,

Ashok r

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Dear Ashok-san,

The following schematic may have less resistance,

but as the analog pin itself has 150 Ohm, IMHO,

less than 10 Ohm will be very difficult to achieve using this device.

WS000000.JPG

Best Regards,

8-Apr-2019

Motoo Tanaka

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Vasanth
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250 sign-ins 500 solutions authored First question asked

Hello Ashok,

A resistance less than 10 ohm is not possible. The analog routing uses switches and analog bus as I specified in the first reply. As the switches itself will take 150-500ohms(depending on the switch), this will not be possible.

Best Regards,

Vasanth

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