TPS51206: VTTREF current limit(Maximum)

David Huang

Intellectual 2285 points

Part Number: TPS51206
Other Parts Discussed in Thread: TPS51200, , TPS51200A-Q1

Hi Team

I notice that the DS specifics 10mA of current limit for the VTTREF pin, which is marked as the minimum value.

Do we have the typical and maximum value of this?

Regards

over 1 year ago

0 Kadeem Samuel over 1 year ago

TI__Genius 12380 points

David,

I believe that the recommendation is to limit the pin to 10mA of current.
This assessment is based on the "Features" Section on the first page of the datasheet:

Thanks,

Kadeem

0 Kadeem Samuel over 1 year ago in reply to Kadeem Samuel

TI__Genius 12380 points

David,

Just to provide a little more information : from an FAQ by Qian Chen, 100uA on the reference output is typically enough for most DDR applications: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/670527/faq-tps51206-frequently-asked-questions-and-answers?tisearch=e2e-sitesearch&keymatch=tps51206%20vttref#

Thanks,

Kadeem

0 David Huang over 1 year ago in reply to Kadeem Samuel

TI__Intellectual 2285 points

Hi Kadeem

I did a test using VLDOIN＝1.5V and VTT/VTTREF both 0.75V, while kept increasing the output current.

It seems like the VTTREF current went up to 20mA before the output voltage started to drop.

I aware that current not higher than 10mA would be the requirement for normal function, but my customer would like to know the output limit of the internal op-amp of the VTTREF. Do we have this info?

The test result is shown as below.

VTTREF

Current[mA] Voltage[V]
0.00 0.744
5.00 0.740
6.00 0.739
7.00 0.739
8.00 0.738
9.00 0.738
10.00 0.737
11.00 0.737
12.00 0.736
13.00 0.736
14.00 0.735
15.00 0.735
16.00 0.735
17.00 0.734
18.00 0.734
19.00 0.733
20.00 0.410
21.00 0.000

Regards

0 yihe over 1 year ago in reply to David Huang

TI__Guru 58080 points

We will look into this and get back to you tomorrow.

Regards

Yihe

0 Kadeem Samuel over 1 year ago in reply to David Huang

TI__Genius 12380 points

David,

I took a look at the testing repository for this part, and it looks like it is not tested at currents exceeding +/- 10mA.

As such, we do not recommend using VTTREF on this part for currents exceeding +/- 10mA.

If more VTTREF current is required, the TPS51200 or TPS51200A-Q1 may be better for your design. Note that these are not pin-to-pin with the TPS51206, but if pin 9 can be unused,

Thanks,

Kadeem

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TPS51206: VTTREF current limit(Maximum)