Hi Experts,
My customer wants to know min Vin when Vout is 5V and Iout is 2.6A.
How can we estimate it?
Regards,
Uchikoshi
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Hi Experts,
My customer wants to know min Vin when Vout is 5V and Iout is 2.6A.
How can we estimate it?
Regards,
Uchikoshi
It depends on efficiency, which is influenced by inductor, temperature. VIN*EFF should be higher than 2V. Assume 85% in the worst case, the minimum Vin can reach to 2.353V.
Calculation
IL*(1-D)=IOUT
IL,MAX=ILIM,MIN=6.5A
1-D=VIN*EFF/VOUT
IOUT=2.6A
So VIN*EFFmin=IOUT*VOUT/IL=2.6*5/6.5=2V
When efficiency is lower, Vin is higher, the worst case we have tested for 2Vin->5Vout/2.6A at -40C is 89%. Given 4% margin for inductance&DCR difference as well as power dissipation on capacitors, the efficiency assumption is 85%.
2/0.85=2.353V
-Wenhao