Buck converter with duty-cycle control
* example of Section B.3.2

.param Va=0.6
.param fs=200KHz
.param L=35uH
.param D=0.676 ; use the quiescent duty cycle found from B.3.2.cpm.cir

.ac DEC 101 10 100KHz
.op

*.options RELTOL=0.01 
*.options GMIN=0.000001  
*.nodeset v(2)=8.1 
*.nodeset v(4)=10
*.nodeset v(nd)=0.68 
*.nodeset v(ni)=0.8 
*.nodeset v(nm1)=3.9

iout 0 4 ac 0 ; use ac 1 to find output impedance

.lib switch.lib

Vg 1 0 12V ac 1 ; use ac 1 to find line-to-output response
Xswitch 1 2 2 0 5 CCM-DCM1 PARAMS: L={L} fs={fs}
L1 2 3 {L}
RL1 3 4 0.05
C1 4 0 100uF
Rload 4 0 10

Vduty 5 0 dc {D}

*Xcpm ctr ni nm1 nm2 5 CPM PARAMS: L={L} fs={fs} va={Va} Rf=1
*Ei ni 0 value={i(L1)}
*Em1 nm1 0 value={V(1)-V(3)}
*Em2 nm2 0 value={V(3)}

*Vc ctr 0 dc 1.4V ac 0 ; use ac 1 to find control-to-output response

.probe
.end