The NT3134 is a PWM controller with comprehensive features for high performance flyback converters. The built-in high-voltage startup circuit consumes zero power at normal operation. A green-mode function continuously decreases the switching frequency under light-load condition. Under no-load condition, the power supply enters burst-mode, which shuts off PWM output when output voltage is high enough and turns on PWM otherwise. This green-mode function enables power supplies to meet international power conservation requirements. The NT3134 integrates a frequency-hopping function that helps reduce EMI emission of a power supply. The synchronized slope compensation for constant output power limit over universal AC input range is also built in. The gate output is clamped at 14V to protect the external MOSFET gate from over?voltage damage. The built-in brown-out protection turns off the converter when low AC mains is detected. The NT3134 discharges the X-Cap to a safe level within specified duration when AC mains disconnection is detected. Protection functions include VDD over-voltage protection (OVP) and under voltage lockout (UVLO), over-load protection (OLP), chip internal thermal protection (CTP), brown-out protection, and a dual mode RT pin protection (RTP-H and RTP-L). The OVP, RTP-H, RTP-L, OLP and CTP are all latch-off type protections.