nelly1
Junior Member level 3
Hello everyone!
I'm trying to design a buck converter with pmos as switch and nmos as diode by using TSMC 65um.
Vin=3.6V Vout=1.2V Iout=150mV Vripple<50mV f=1MHZ
I caculated : L=8uH C=0.25uF R=8Ω
I have two questions now and hope someone can help me:
1.For the pmos as switch, i caculated the power loss(conduction loss and switch loss)to get the optimum W/L value.But for the diode which using the nmos i don't know how to determine the W/L value of the mosfet in order to get the lowest power loss.
2.because there is impossible to set the diode voltage to zero, the Vl is increased so that the Il as well as Ir are also increased. Should i change the Rload value to get Vout=1.2V?(now the design is only a open loop without PWM and so on).
Any advices will be appreciated!!
I'm trying to design a buck converter with pmos as switch and nmos as diode by using TSMC 65um.
Vin=3.6V Vout=1.2V Iout=150mV Vripple<50mV f=1MHZ
I caculated : L=8uH C=0.25uF R=8Ω
I have two questions now and hope someone can help me:
1.For the pmos as switch, i caculated the power loss(conduction loss and switch loss)to get the optimum W/L value.But for the diode which using the nmos i don't know how to determine the W/L value of the mosfet in order to get the lowest power loss.
2.because there is impossible to set the diode voltage to zero, the Vl is increased so that the Il as well as Ir are also increased. Should i change the Rload value to get Vout=1.2V?(now the design is only a open loop without PWM and so on).
Any advices will be appreciated!!