• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 33 subscribers
  • Views 379 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LMH1297: Regarding the current at initialization

Masaru Tamai
Prodigy 235 points
Part Number: LMH1297
Other Parts Discussed in Thread: LMH0397

Hello.

We are evaluating LMH1297 and LMH0397.

We have noticed that the current at initialization changes significantly when measuring the device current.

Even with the same device, current will change if it is turned off and on repeatedly.

The same phenomenon occurs with the LMH1297 EVM.

We have three questions.

 -What is the reason for the change in current?

 -Is it acceptable as a device?

 -What is the maximum current?

Best Regards,Regarding the current at initialization.xlsx

  • 0
    TI__Guru* 93670 points

    Greetings,

    Greetings,

    1). When you are measuring this current, can you please let us know LMH1297 device setup? For example is it operating in equalizer or cable driver mode? Any signal on the 100 ohm input.

    2). What is the sate of ENABLE pin? Does pulling ENABLE pin low during power up and pulling ENABLE pin high after VCC is stabilized makes any difference?

    3). Maximum current consumption could go as high as 290mA while it is acquiring lock.

    Regards,,nasser

  • 0 in reply to Nasser Mohammadi
    Prodigy 235 points

    Hello Nasser-san,

    Thank you for your response.

    1). When you are measuring this current, can you please let us know LMH1297 device setup? For example is it operating in equalizer or cable driver mode? Any signal on the 100 ohm input.

      -> We use in equalizer mode which enabled the through-out function.

    2). What is the sate of ENABLE pin? Does pulling ENABLE pin low during power up and pulling ENABLE pin high after VCC is stabilized makes any difference?

      -> There is no difference if power is turned on with the ENABLE pin low.

    3). Maximum current consumption could go as high as 290mA while it is acquiring lock.

      -> Does it not exceed 290mA at the time of initialization?

    Best regards,

  • 0 in reply to Masaru Tamai
    TI__Guru* 93670 points

    Greetings Tamai-San,

    Current consumption when VCC is stable at worst case could be up to 290mA.

    During power up and before VCC is stable current may go higher but in this event this would be treated like an ESD event.

    Regards,,nasser

  • 0 in reply to Nasser Mohammadi
    Prodigy 235 points

    Hello Nasser-san,

    Thank you for your reply.

    We understand that current can flow up to 290mA when VCC is stable.

    Best regards,

    Tamai