NCP1377数据手册集成电路（IC）的ACDC转换器离线开关规格书PDF

描述 Description

The NCP1377 combines a true current mode modulator and a demagnetization detector which ensures full borderline / critical Conduction Mode in any load/line conditions together with minimum drain voltage switching (Quasi-Resonant operation). Due to its inherent skip cycle capability, the controller enters burst mode as soon as the power demand falls below a predetermined level. As this happens at low peak current, no audible noise can be heard. For NCP1377, an internal 8.0µs timer prevents the free-run frequency to exceed the 150kHz CISPR-22 EMI starting limit while the skip adjustment capability lets the user select the frequency at which the burst foldback takes place. For NCP1377B, the internal timer duration is reduced to 3.0µs to allow operation at higher frequencies.The transformer core reset detection is done through an auxiliary winding which, brought via a dedicated pin, also enables fast Over-Voltage Protection (OVP). Once an OVP has been detected, the IC permanently latches-off. The 1377 features a sampling time of 4.5µs whereas it is 1.5µs for the B version.The NCP1377 also features an efficient protective circuitries which, in presence of an overcurrent condition, disables the output pulses and enters a safe burst mode, trying to re-start. Once the default has gone, the device auto-recovers. Finally an internal 1ms soft-start eliminates the traditional startup stress.

特性 Features

Free-running borderline / critical mode quasi-resonant operation
Latched Over Voltage Protection
Auto-recovery short-circuit protection via UVLO crossover
External latch triggering, e.g. via over-temperature signal
Current-Mode with adjustable Skip-cycle capability
Internal 1ms soft-start
Internal temperature shutdown
Internal Leading Edge Blanking
500mA peak current source/sink capability
Under Voltage Lockout level of 12.5V (on) and 7.5V (min)
Direct optocoupler connection
SPICE models available for TRANsient analysis
Internal minimum TOFF
Auxiliary power supplies (USB, appliances, TVs etc.)
Pb-Free Packages are Available

应用 Application

AC/DC adapters for notebooks etc.Offline battery chargersConsumer electronics (DVD players, set-top boxes, TVs, etc.)Auxiliary power supplies (USB, appliances, TVs etc.)

简介

NCP1377属于集成电路（IC）的ACDC转换器离线开关。由制造生产的NCP1377AC DC 转换器，离线开关该系列是元器件级控制产品，用于构建将交流市电转换为直流电（通常电压大幅降低）的设备。集成和未集成系统主要开关元件的器件均包括在内。由于高输入输出电压比，以及此类系统中通常需要隔离，这些器件通常与外部变压器配合使用。尽管通常使用定制变压器来实现此用途，但也有许多专门用于此用途的库存产品，请参见“开关转换器，SMPS 变压器”标题。