AnsweredAssumed Answered

AD8232 outputting noise.

Question asked by beingmachine on Aug 15, 2017
Latest reply on Apr 4, 2018 by jrombola

Hello,
I am new to this forum, I am building a Sports Device where i am using AD8232 to record BPM of an individual, I am working on Figure 64. Circuit for Heart Rate Measurement at Hands, We have made our PCBs with AD8232 and it's components in the schematics. I am analog reading the values using Arduino from the output. I can see only noise is coming from it..

 

More over i have SparkFun Board , it comes with the Figure 66. Circuit for ECG Waveform Monitoring configuration, I have altered the board to Heart Rate Measurement at Hands and it's working properly, as i wanted

 

 I have used Altered SparkFun board as reference and noted down voltage across each pins and compared it with my own designed PCB.

 

The voltages are as follows : 

 

SparkFun board Voltage       Own Designed PCB

1: 1.52                                   1: 1.63

2: 0.31                                   2: 0.29                         

3: 0.30                                   3: 0.29

4: 2.59                                   4: 2.57

5: 0.00                                   5: 0.01

6: 1.66                                   6: 1.49

7: 0.55                                   7: 0.52

8:1.66                                    8 1.63

9: 1.6                                     9: 1.63

10: 1.6                                   10: 1.63

11: 2.44                                 11: 3.26

12: 3.29                                 12: 3.26

13: 3.26                                 13: 3.26

14: 0.00                                 14: 0.00

15: 3.29                                 15: 3.26

16: 0.00                                 16: 0.00

17:3.29                                  17: 3.26

18: 0.28                                 18: 0.27

19: 1.65                                 19: 1.63

20: 0.30                                  20: 0.29

 

I have tested LDO+ and LDO- pins from AD8232 and it's detecting when i remove leads..When the leads gets off these pins are getting HIGH and when connected it's getting LOW..
I can see output at IAOUT below is the screenshot of ADC recording signal at IAOUT..


But the output only noise, I cannot see any signal.. what could be the problem.? is the parts of capacitor and resistors are specified.? I am using 5% Resistors and 10% ceramic 
capacitors..
See attached schematics along with this ticket
Please help.

 

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