Does anyone have the experience of ST7540? (The Power line communication transceiver, very similar to ST7538 )
Datasheet is below:
I have two boards which both have ST7540 module(host-controller board & terminal board), (we setup ST7540@132.5KHz, 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