Hi
I am DFAE in Japan.
Our customer is designing LTM4607.
But we can not understand to calculate Design examples of Rsense.
At Buck mode operation
Vin=12V to 36V, Vout=12V, f=400kHz,P=120W(Iout=10A) η=0.95 L=4.7uH
So, Iout=IL=120W/(12V) =10A.
ΔIL=10Ax(36V-12V)x12Vx12V/(36Vx4.7uHx400kHzx120W)=4.26A
Rsense=2x0.13/(2x120W/12V-4.26A)=16.5mΩ
But data sheet mention 9mΩ. Can you tell me how to calculate 9mΩ?
I can not undesstand how to caluculate 30% safety margin.
At Boost mode operation
Vin=5V to 12V, Vout=12V, f=400kHz,P=60W(Iout=5A) η=0.95 L=3.3uH
So, Iin=IL=60W/(5Vx0.95) =12.63A.
ΔIL=12.63Ax(12V-5V)x5Vx5Vx0.95/(12Vx3.3uHx400kHzx60W)=2.21A
Rsense=2x0.16x5V/(2x5Ax12V+2.21Ax5V)=12.2mΩ
But data sheet mention 7mΩ. Can you tell me how to calculate 7mΩ?
Best regards
N.Kokubo