6.1 First-Order Memristor Circuits
237
Fig. 6.12 Saddle-node
bifurcation of the EP
¯
ϕ M = −1 when varying Q 0
in a neighborhood of 2/3
−1
Q 0 <
2
3
◦
•
ϕ M
dϕM
dt
−1
Q 0 =
2
3
×
ϕ M
dϕM
dt
−1
Q 0 >
2
3
ϕ M
dϕM
dt