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TLV767: Feedback resistors for 5Vout

Jade Han
Intellectual 1685 points
Part Number: TLV767

Tool/software:

Hello team,

Currently my customer is reviewing TLV76701 for their induction project.

They want to do 12Vin 5Vout, and asked which feedback resistors they should use.

Based on quick calculations I thought R1 = 787kohm, R2 = 150kohm would be suitable,

Could you please check below calculations, and would it be ok if they used these values? I just wanted to double check to make sure.

i) VOUT = VFB × (1 + R1 / R2)

5 = 0.8 x (1 + R1/R2)

R1/R2 = 5.25

 

ii) R1 + R2 ≤ VOUT / (IFB × 100)

R1 + R2 ≤ 5 / (50nA × 100)

R1 + R2 ≤ 5 / (50nA × 100)

R1 + R2 ≤ 1MΩ

 

R2 = 150kohm

R1 = 787kohm

Thank you in advance for your help and support.

  • 0
    TI__Expert 5410 points

    Hi Jade,

    Those values will work as expected, they divide correctly, ensure IFB is negligible, and don't require a CFF.

    I'd note that feedback divider current (Vref/R2) is 5.3uA which is just barely above the 5uA cutoff for requiring a CFF.

    If you want to create a wider margin when not including a CFF, you can cut reduce both.

    Best,

    Gregory Thompson