TSB81BA3 use of internal regulator clarification

Frank D'Aliesio

Other Parts Discussed in Thread: TSB81BA3E

The data sheet mentions to tie VREG_PD to Vdd for normal operation of the TSB81BA3. If I do that, I cannot use the internal 1.95V regulator and eliminate one extra part.

The TESTM, VREG_PD, SE, and SM terminals are used to set up various manufacturing test conditions. For

normal operation, the TESTM and VREG_PD terminals must be connected to VDD through a 1-kΩ resistor. The

SE and SM terminals must be tied to ground through a 1-kΩ resistor.

Can you please clarify how I can use the internal regulator to generate 1.95V if I need to tie Vreg_PD to VDD for normal operation?

Thank you,

Frank

over 14 years ago

0 Elias Villegas M. over 14 years ago

TI__Guru* 76130 points

Hello Frank,

We are reviewing your inquiry, can you attach the document in which you are seeing that information regarding VREG_PD.

Regards.

0 Frank D'Aliesio over 14 years ago in reply to Elias Villegas M.

Intellectual 715 points

The TSB81BA3E can be powered by a single 3.3-V supply when the VREG_PD terminal (terminal 73 on the PFP

package and terminal B7 on the ZAJ package) is tied to GND. VREG_PD enables the internal 3.3-V to 1.95-V

regulator which provides the 1.95-V to the core.

Datasheet for the TSB81BA3E, second paragraph in the Description section, page 2.

The TESTM, VREG_PD, SE, and SM terminals are used to set up various manufacturing test conditions. Fornormal operation, the TESTM and VREG_PD terminals must be connected to VDD through a 1-kΩ resistor. The SE and SM terminals must be tied to ground through a 1-kΩ resistor.

Datasheet for TSB81BA3E also in Description section, page 3, second to last paragraph.3252.tsb81ba3e.pdf

0 Elias Villegas M. over 14 years ago in reply to Frank D'Aliesio

TI__Guru* 76130 points

Hello Frank,

Thanks for specifying that you are using the "E" version.

You can tie VREG_PD to ground in order to enable the internal regulator.

Please dismiss the "...for normal operation..." paragraph.

Regards.

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TSB81BA3 use of internal regulator clarification