How to keep analog output voltage exchanged by AMUX

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Anonymous
Not applicable

Hello,

I output analog voltage converted by DAC to some analog output pins through Analog MUX.

The below is my circuit image in PSoC6.

VDAC -----> AMUX -----> output pin

             |--> AMUX -----> output pin

             |--> AMUX -----> output pin

             |--> AMUX -----> output pin

FW select one of them to output the analog signal from DAC, and the other three output pins keep the previous voltage.

Please let me know any way.

Best regards,

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1 Solution
MeenakshiR_71
Employee
Employee
100 likes received 50 likes received 25 likes received

Hello user_474444345​,

In order for the pin to retain the voltage, you will need to add capacitors to the pins. You can do a simple TopDesign configuration like shown below for your design. Make sure you use VDAC's output buffer configuration as "Buffered to pin". This enables OpAmp buffer on the VDAC output path and provides fast enough charge source for the caps on the external pin. Using the below config and external cap, you can simply change the pin you want VDAC to drive using the AMUX API "AMux_1_Select" or "AMux_1_FastSelect".

pastedImage_0.png

Let me know if this helps.

Regards,

Meenakshi Sundaram R

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1 Reply
MeenakshiR_71
Employee
Employee
100 likes received 50 likes received 25 likes received

Hello user_474444345​,

In order for the pin to retain the voltage, you will need to add capacitors to the pins. You can do a simple TopDesign configuration like shown below for your design. Make sure you use VDAC's output buffer configuration as "Buffered to pin". This enables OpAmp buffer on the VDAC output path and provides fast enough charge source for the caps on the external pin. Using the below config and external cap, you can simply change the pin you want VDAC to drive using the AMUX API "AMux_1_Select" or "AMux_1_FastSelect".

pastedImage_0.png

Let me know if this helps.

Regards,

Meenakshi Sundaram R