Housed in a SO-14 package, the NCP1381/82 includes everything needed to build rugged and efficient Quasi-Resonant (QR) Switching Power Supplies. When powered by a front-end Power Factor Correction circuitry, the NCP1381/82 automatically disconnects the PFC controller in low output loading conditions (with an adjustable level), thus improving the standby power. This is particularly well suited for medium to high power offline applications, e.g. notebook adapters. When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the so-called skip cycle mode and provides excellent efficiency at light loads. Because this occurs at an adjustable low peak current together with a proprietary Soft-Skip technique, no acoustic noise takes place. Skip cycle also offers the ability to easily select the maximum switching frequency at which foldback and standby take place.
The NCP1381/82 also features several efficient protection options like a) a short-circuit / overload detection independent of the auxiliary voltage b) an auto-recovery brown-out detection and c) an input to externally latch the circuit in case of Overvoltage Protection or Over Temperature Protection.
Features
•Current-Mode Quasi-Resonant Operation
•Adjustable Line Over Power Protection
•Extremely Low Startup Current of 15 A Maximum
•Soft-Skip Cycle Capability at Adjustable Peak Currents
•Plateau Sensing Overvoltage
•Brown-Out Protection
•Maximum tON Limitation
•Overpower Protection by current Sense Offset
•Internal 5 ms Soft-Start Management
•Short-Circuit Protection Independent from Auxiliary Level
•External Latch Input Pin for an OTP Signal
•Go-T o-Standby Signal for the PFC Front Stage
•T rue Frequency (tON + tOFF) Clamp Circuit
•Low and Noiseless, No-Load Standby Power
•Internal Leading Edge Blanking
•+500 mA / -800 mA Peak Current Drive Capability
•5 V / 10 mA Reference Voltage
•This is a Pb-Free Device
Typical Applications
•High Power AC/DC Adapters for Notebooks, etc
•Of fline Battery Chargers
•Set-T op Boxes Power Supplies, TV, Monitors, etc
Click to view :
NCP1381.PDF
