LMX2572: TICS Pro Charge Pump gain inconsistency

Jonas Reber

Part Number: LMX2572

Datasheet and TICSPro inconstistency once more. Minor issue but should be fixed.

This table (22) is not consistent with table (2) of the datasheet:

Worse yet - if I set my device to CPG = 8 (that is 2500) it does not lock/work, if I set it to CPG = 4 (that is 2500 again) it DOES lock. What is going on here?

over 6 years ago

0 Noel Fung over 6 years ago

TI__Guru** 108110 points

Hi Jonas,

I believe the numbers shown in TICS, table 2 and table 22 are matched. Would you please point me to the errors?
In addition, there is no different between CPG=4 or 8, the PLL remains locked. Do you have specific configuration that does not lock when using different CPG setting? I can give it a trial.

0 Jonas Reber over 6 years ago in reply to Noel Fung

Prodigy 90 points

Hi Noel

Well Table 22 says „each increment adds 625uA“ while Table 2 does not show that. In my school 8*625uA was 5000 and not 2500? But maybe I did interpret table 22 wrong? The dots for me mean ... the values continue as a series?

Thanks

0 Noel Fung over 6 years ago in reply to Jonas Reber

TI__Guru** 108110 points

Hi Jonas,

That's why we have table 2 in the very beginning of the datasheet :).

0 Jonas Reber over 6 years ago in reply to Noel Fung

Prodigy 90 points

I see. Well maybe you could add a little note there, referring to table 2 or change the wording from "each increment adds" to "see table 2". I did acknowledge table 2 (it has only recently been added) but I referred to table 22 in my driver assuming a value of 8 would give 5000uA while in reality i was 2500. This could save someone elses time in the future too.

0 Noel Fung over 6 years ago in reply to Jonas Reber

TI__Guru** 108110 points

Agree. Will update it in next revision.

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LMX2572: TICS Pro Charge Pump gain inconsistency