TPS717: voltage regulator the margin

user4499359

Part Number: TPS717

I want to use a TPS71701 as a voltage regulator with a DAC output range of 0-3.3V. The DAC may not output 0 but it does not affect use. The regulator output range is 2.5-5V.

Which is the VREF. By the way, if the TPS71701 chip is suitable, the fluctuation of the adjustment is much.

Parameter	Value
V_REF
V_NOM	3.75V
ΔV_DAC	3.3V
ΔV_MARG	2.5V
R₂	324kΩ
V_DACN	1.65V

over 5 years ago

0 Ryan Eslinger over 5 years ago

TI__Guru 55940 points

Hi,

Thanks for looking at the blogs! I am posting a link to the blog for others to find.

e2e.ti.com/.../give-your-voltage-regulator-the-margin-it-deserves

TPS71701 should work with this configuration (as should LDO where you have access to the FB node); however, it is important to note that we have not attempted your specific application. Keep in mind that when you change the voltage the LDO will need time to react to the change. When lowering the LDO voltage, it will be up to the load to pull the voltage down to the new voltage.

Very Respectfully,
Ryan

0 user4499359 over 5 years ago in reply to Ryan Eslinger

Intellectual 450 points

Thank you, I want to confirm the internal reference voltage VREF of the TPS71701.

0 Ryan Eslinger over 5 years ago in reply to user4499359

TI__Guru 55940 points

Hi ,

The Band Gap voltage is divided down to be nominally 0.793 V. As such, when the LDO output is at the set voltage, Vfb should be 0.793 V.

Very Respectfully,

Ryan

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TPS717: voltage regulator the margin