AN3213 datasheet(57/64 Pages) STMICROELECTRONICS

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AN3213

FAQs and troubleshooting

Doc ID 17429 Rev 1

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with an amplitude equal to the TX_OUT programmed level multiplied by the PA

gain (nearly 4.5). In this case, there is no problem regarding the AFE and PA

Check the ZC_IN_A (or ZC_IN_D, if it has been selected): a signal synchronous to

the mains voltage must be present for the ST7570 to be able to transmit in

operating mode

Verify, via the ST7570 GUI, if the node is synchronized.

Problem: the ST7570 demonstration board transmits only for a short while.

●

What to check:

Verify the internal temperature of the ST7570, available inside the management

information base (MIB), and accessible via the ST7570 GUI

Check if there is short-circuit (i.e. capacitive) impedance on the mains at the

carrier frequency. It may lead to device overheating and PA thermal shutdown.

Problem: the ST7570 demonstration board does not receive.

●

What to check:

Check if the transmitted signal reaches the ST7570 device by measuring the

RX_IN line voltage (TP5) with the oscilloscope probe referred to VSSA signal

ground

Check that the GUI is setting the transmitter and the receiver to use the same tone

frequencies

Check the ZC_IN_A (or ZC_IN_D, if it has been selected): a signal synchronous to

the mains voltage must be present for the ST7570 to be able to receive in

operating mode

Problem: During a communication test, the ST750 GUI shows a high bit error rate

(BER).

Note:

(This point refers to a half-duplex communication involving two ST7570 demonstration

boards communicating with each other).

●

What to check:

Check that both demonstration boards have the same ST7570 GUI settings

Verify the SNR of the communication. If the signal is too low or the noise is too

high with respect to each other, the communication performance is poor. Try to:

Check the S and N estimation of the receiving ST7570 device

Measure the signal level S and the noise level N on the RX_IN line (TP5) of the

receiving board.

AN3213 Datasheet(PDF) 57 Page - STMicroelectronics