The NCP1362 is a highly integrated primary side quasi−resonant

flyback controller capable of controlling rugged and

high−performance off−line power supplies.

Thanks to a Novel Method this new controller saves the secondary

feedback circuitry for Constant Voltage and Constant Current

regulation, achieving excellent line and load regulation without

traditional opto coupler and TL431 voltage reference.

The NCP1362 operates in valley lockout quasi−resonant peak

current mode control mode at high load to provide high efficiency.

When the power on the secondary side starts to diminish, the

controller automatically adjusts the duty−cycle then at lower load the

controller enters in pulse frequency modulation at fixed peak current

with a valley switching detection. This technique allows keeping the

output regulation with tiny dummy load. Valley lockout at the first 4

valleys prevent valley jumping operation and then a valley switching

at lower load provides high efficiency.

Features

• Constant Voltage Primary−Side Regulation < ±5

• Constant Current Primary−Side Regulation < ±5

• LFF and BO Feature on a Dedicated Pin:

♦ BO Detection

♦ LFF for CC Regulation Improvement

• Quasi−Resonant with Valley Switching Operation

• Optimized Light Load Efficiency and Stand−by Performance

• Maximum Frequency Clamp (No Clamp, 80, 110 and 140 kHz)

• Cycle by Cycle Peak Current Limit

• Output Voltage Under Voltage and Over Voltage Protection

(UVP or OVP)

• Secondary Diode or Winding Short−Circuit Protection

• Wide Operation VCC Range (up to 28 V)

• Low Start−up Current

• CS & VS/ZCD Pin Short and Open Protection

• Internal Temperature Shutdown

• Internal and Fixed Frequency Jittering for Better EMI Signature

• Dual Frozen Peak Current to Both Optimize Light Load Efficiency

(10 Load) and Stand−by Performance (No−load)

• Fault Input for Severe Fault Conditions, NTC Compatible for OTP

• These are Pb−Free Devices

Applications

• Low Power ac−dc Adapters for Routers and Set−Top Box

• Low Power ac−dc Adapters for Chargers