LMH0071: About RXCLK

Masakazu Adachi

Part Number: LMH0071

Hello team,

I have a question about RXCLK.

If the output of the signal generator is input to RXIN0 when it is not settled, does it affect the frequency output from RXCLK?

The details of the question are as follows,

Good condition: Input 270 MHz to RXIN0 while the signal generator signal is settling. 27 MHz output from RXCLK is confirmed.

Bad condition: Input while starting up the signal generator, settles to 270MHz in about 3 seconds; RXCLK output is locked at 27.5MHz~28MHz.

Please let me know your opinion.

Regards,

Masakazu

over 3 years ago

0 Nasser Mohammadi over 3 years ago

TI__Guru* 93670 points

Greetings,

Since the output of the signal generator is not settled, device cannot correctly recover the recovered clock. Once the signal generator output is settled then we should be able to recovered the received clock correctly.

Regards,,Nasser

0 Masakazu Adachi over 3 years ago in reply to Nasser Mohammadi

TI__Intellectual 2500 points

Hello Nasser,

The customer states that RXCLK is 27.5MHz~28MHz even after the signal generator output has settled to 270MHz. He has tried leaving it for hours but the result is still the same.

Is there any way to resolve this?

Regards,

Masakazu

+1 Nasser Mohammadi over 3 years ago in reply to Masakazu Adachi

TI__Guru* 93670 points

Greetings,

To get out of this mode, we either have to lose signal on the input of the device and re-apply the signal or disable and enable the device through the ENABLE pin. These forces the CDR state machine to restart the lock acquisition.

Regards,,Nasser

0 Masakazu Adachi over 3 years ago in reply to Nasser Mohammadi

TI__Intellectual 2500 points

Hello Nasser,

Thanks to the support.

I understand.

Regards,

Masakazu

0 Masakazu Adachi over 3 years ago in reply to Masakazu Adachi

TI__Intellectual 2500 points

Hi Nasser,

Where is the ENABLE pin setting written in the datasheet?

Is it RX_MUX_SEL?

Regards,

Masakazu

+1 Nasser Mohammadi over 3 years ago in reply to Masakazu Adachi

TI__Guru* 93670 points

Greetings Adachi-San,

Please use RESET pin. By bringing this pin high and then low, we are re-starting the CDR state machine.

Regards,Nasser

0 Masakazu Adachi over 3 years ago in reply to Nasser Mohammadi

TI__Intellectual 2500 points

Hello Nasser-san,

Thanks. I understood it well.

Regards,

Masakazu

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LMH0071: About RXCLK