When the common-mode input voltage is significantly higher than V_cross, the third PMOS transistor P11 turns “on” and the second PMOS transistor P8 turns “on” (i.e., the current stealing switch closes). When PMOS transistor P11 is “on,” the tail current (I₂) from the second current source 580 is prevented from flowing through the PMOS transistors (P9 and P10) in the second PMOS input pair to the NMOS transistors (N9 and N10) in the second NMOS current mirror. Since no current flows through NMOS transistor N10, I_steal=0 when the common-mode input voltage is significantly greater than V_cross.

When the common-mode input voltage is significantly lower than V_cross, the third PMOS transistor (P11) turns “off” and the second PMOS transistor (P8) turns “off” (i.e., the current stealing switch opens). When PMOS transistor P11 is “off,” the tail current (I₁) from the second current source 580 flows through the PMOS transistors (P9 and P10) in the second PMOS input pair to NMOS transistor N10 in the second NMOS current mirror. Although current is flowing through NMOS transistor N10, the second PMOS transistor (P8) is turned “off” when the common-mode input voltage is less than V_cross to cut off the stolen current. Thus, I_steal=0 when the common-mode input voltage is significantly lower than V_cross.