PIC16F677 & Melexis TH72002 circuit problem

[ben8118]

Dear All,

I have a problem on using Melexis TH72002. I construct the circuit as the attachment schematic, I unable to see the signal transmit out. I using the spectrum analyzer to check the signal.

 

[milesguidon]

Make sure that you are not pulling ENTX low, as this will disable transmission--there is no need for that 10k resistor in series between the microcontroller I/O and the ENTX pin, and you don't need that 100nF capacitor on the ENTX pin, either.

Verify with a logic analyzer/oscilloscope that you have switching data directly at the ASKDTA pin of the TH72002.

Finally, make sure that the voltage between the VCC and VEE pins of the TH72002 is above the minimum required operating voltage.

 

[ben8118]

Thanks for the information.

I have done what you say, but still no luck.

The Vcc voltage is 3.15V. The ASKDTA pin have data.

Spectrum analyzer does not receive any signal.

 

[milesguidon]

Have you considered the possibility that your spectrum analyzer is setup incorrectly?