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PSoC™ 4 Forum Discussions

RoFr_4201436
Level 3
Level 3
50 sign-ins 25 sign-ins 10 replies posted

Hello everyone,

I created a program in PSOC 4 BLE, but the opamp_1's analog port P2[2] and ADC's analog port P3[4] have a voltage of 3 V and i don't know why, someone can help to get solution about it? Just send the program for your PSOC 4 and test with a multimeter the ports P2[2] and P3[4] that you can see the voltage, don't need to create the circuit.

pastedImage_0.png

Follows the attachment of my program:

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1 Solution

What is the voltage of the RA and LA inputs?

The differential amplifier consisting of opamp_1 and opamp_2 amplifies the voltage difference of the RA and LA inputs.   If the difference is too big the output of opamps will be saturated.

The DC potential of the positive input of the opamp_4 is zero volt.  Any bias voltage is required at the input because the opamp_4 is used as a non-inverting amplifier.

I recommend to use a differential input of the ADC.  Please refer following code example and documents.

https://www.cypress.com/documentation/code-examples/ce95272-psoc-4-sar-adc-and-differential-amplifie...

CE95272 - PSoC® 4 SAR ADC and Differential Amplifier

Regards,

Noriaki

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3 Replies
NoriakiT_91
Employee
Employee
100 likes received 50 likes received 25 likes received

What is connected to the RA and LA inputs?

Regards,

Noriaki

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RA - Right Arm

LA - Left Arm

I'm trying to implement a eletrocardiogram

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What is the voltage of the RA and LA inputs?

The differential amplifier consisting of opamp_1 and opamp_2 amplifies the voltage difference of the RA and LA inputs.   If the difference is too big the output of opamps will be saturated.

The DC potential of the positive input of the opamp_4 is zero volt.  Any bias voltage is required at the input because the opamp_4 is used as a non-inverting amplifier.

I recommend to use a differential input of the ADC.  Please refer following code example and documents.

https://www.cypress.com/documentation/code-examples/ce95272-psoc-4-sar-adc-and-differential-amplifie...

CE95272 - PSoC® 4 SAR ADC and Differential Amplifier

Regards,

Noriaki

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