ST7540 problem

S

Shawn Chen

Jan 1, 1970
0
Does anyone have the experience of ST7540? (The Power line
communication transceiver, very similar to ST7538 )

Datasheet is below:
http://www.st.com/stonline/products/literature/ds/12176.htm

I have two boards which both have ST7540 module(host-controller board
& terminal board),
(we setup [email protected], all circuit follows the ST7540 reference
design - the 132.5KHz circuit. all config bit is default.)
We don't have the zero crossing circuit.

Now we can send and receive data well in about 20m distance(office
environment, lots of computer and fluorescent lamp), but when the
distance gets longer, the data will get error.

The signal is about 30dB on the transfer side and almost 0dB on the
receive side.( 20m distance, I don't have a frequency spectrograph and
the 30dB is the result of FFT from a oscilloscope.)

Any hits? Any of your help will be appreciated!

Regards,
Shawn
 
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