SPICE Behavioural Bv and Bi sources example

.param Rvalue = 2k
.param Vswing = 0.5
.param Avol = 1k

V1 in 0 SIN(0 1 10k)
R1 in A 1k
* Fixed behavioural resistor
B1 A B I=V(a,b)/Rvalue 
R2 B 0 1k
V2 Rvariable 0 SIN(1 1 1k 0 0 -90)
R3 in C 1k
* Voltage controlled behavioural resistor (minimum resistance = 1u)
B2 C D I=V(c,d)/max(Rvalue * v(Rvariable), 1u)
R4 D 0 1k

* Difference 1
B3 DIFF1 0 V=V(a,b)
* Difference 2
B4 DIFF2 0 V=V(c,d)
* Simple behavioural comparator
B5 COMPARATOR_OUT 0 V={Vswing * tanh(V(diff1)* Avol)}
* Squaring an input
B6 SQUARE_OUT 0 V=V(diff2)^2

.tran 2u 2m

.options savecurrents

.control
run
listing param
plot in diff1 rvariable diff2
plot @b1[i] @b2[i]
plot diff1 comparator_out
plot diff2 square_out
.endc
.end