LMH1218: Programming Issue

John Griffith

Mastermind 21811 points

Part Number: LMH1218

Hello,

My customer has an issue with LMH1218, can you help?

I can not read correct CDR status and VCO setting as programming guide, but I could get correct parameters by add extra two release reset command as following. I do not know the reason, my SCL frequency is 100KHz.

2. Now, parameters are correct, but HEO and VEO are 0 as below screenshot, could you help me?

Thanks,

John

over 3 years ago

0 Nasser Mohammadi over 3 years ago

TI__Guru* 93670 points

Hi John,

This is unexpected. Given CDR is locked we should observe HEO/VEO - otherwise device will not be locked.

1). Please confirm customer is indeed using correct methodology for reading/writting into the registers. Please note below FAQ for details.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/897323/faq-lmh1297-programming-raw-command-syntax-explained/3317304#3317304

2). It would be highly desirable - i believe i already mentioned this - for customer to use LMH1218EVM. Given this, EVM can be used for correlation. Additionally customer can use GUI that is used for this EVM - to connect to his own board/device during development. This makes board bring up much more smoothly.

Regards,,nasser

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LMH1218: Programming Issue