TUSB1210 Vbat recommended voltage

Gerardo Tadeo de la Garza Mora

Hi,

one of my customers is asking what should be the voltage of Vbat if Vdd33 is shorted to Vbat externally. He is confused because we suggest different voltages on the DS:

1. first we say that Vbat shouldn't be under 3.3V

2. then we say that Vbat min is 3.05V

3. And we also give the following range for Vbat 3.2-3.6V

Which would be the recommended voltage for Vbat, and why are several different voltages recommended?

What would be the recommended voltage for Vbat when Vdd33 is supplied by the internal LDO?

thanks,

Tadeo

over 8 years ago

0 Gerardo over 8 years ago

TI__Genius 11280 points

Hello Gerardo,
In the case VDD33 shorted externally to VBAT, here VBAT allowed range is [3.05V : 3.6V].

Regards,
Gerardo

0 Gerardo Tadeo de la Garza Mora over 8 years ago in reply to Gerardo

TI__Prodigy 380 points

Hi Gerardo,

Thanks for the reply. Just one more thing, why do we mention different voltages/voltage ranges? It makes it confusing for the customer. Also, what would be the recommended nominal voltage? I would guess it would be 3.3V, but please correct me if I'm wrong.

thanks,
Tadeo

0 Gerardo Tadeo de la Garza Mora over 8 years ago in reply to Gerardo

TI__Prodigy 380 points

Sorry to bother, but any input on my question regarding nominal Vbat voltage?

0 Gerardo Tadeo de la Garza Mora over 8 years ago in reply to Gerardo

TI__Prodigy 380 points

Hi Gerardo,

Any inputs?

thanks,
Tadeo

0 Gerardo over 8 years ago in reply to Gerardo Tadeo de la Garza Mora

TI__Genius 11280 points

Hello Tadeo,
Sorry for the delay.

Yes, you can recommend nominal voltage +3.3V .

Regards,
Gerardo

0 Gerardo Tadeo de la Garza Mora over 8 years ago in reply to Gerardo

TI__Prodigy 380 points

Hi Gerardo,

Thanks for the reply. Just one more question remains, what is the value of Vdd33 when the internal LDO is used? From table 4.6 it seems that it is programmable, or am I understanding this incorrectly? if it is programmable, would it also be recommended to use 3.3V?

thanks,
Tadeo

0 Gerardo over 8 years ago in reply to Gerardo Tadeo de la Garza Mora

TI__Genius 11280 points

Hi Tadeo,

The default value of VUSB3V3_VSEL is "011" with default target value [3.0v: 3.1v, 3.2v][Min: Typ: Max].

Here VBAT allowed range is [3.05V : 3.6V]. VDD33 internal regulator remains ON, with default target value [3.0V : 3.1V : 3.2V] [Min : Typ : Max].

In my understanding the default value of VUSB3V3_VSEL is ok, but the customer can choose some between "011" and "111"

Regards,
Gerardo

Regards,

Gerardo

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TUSB1210 Vbat recommended voltage