MOSFET is controlled by this pin. MOSFET switching isterminated when a current greater than a threshold current isdrawn from this pin. Switching resumes when the current beingpulled from the pin drops to less than a threshold current. Amodulation of the threshold current reduces group pulsing. Thethreshold current is between 75 μA and 115 μA.The EN/UV pin also senses line undervoltage conditions throughan external resistor connected to the DC line voltage. If there isno external resistor connected to this pin, TinySwitch-III detectsits absence and disables the line undervoltage function.