NCP1338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 NCP1338 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). The transformer core reset detection is done internally, without using any external signal, due to the Soxyless concept. The frequency is internally limited to 130 kHz, preventing the controller from operating above the 150 kHz CISPR-22 EMI starting limit.By monitoring the feedback pin activity, the controller enters skip mode as soon as the power demand falls below a predetermined level. As each restart is softened by an internal Soft-Skip™, and as the frequency cannot go below 25 kHz, no audible noise can be heard.The NCP1338 also features an efficient protective circuitry which, in presence of an overcurrent condition, disables the output pulses and enters a safe burst mode, trying to restart. Once the default has gone, the device auto-recovers. Also included is a bulk voltage monitoring function (known as brown-out protection), an adjustable overpower compensation, and a VCC OVP. The Fault Timer is reset by any of these conditions, to ensure that the controller immediately restarts when the condition disappear. Finally, an internal 4.0 ms Soft-Start eliminates the traditional startup stress. NCP1338 can be used in applications where the VCC supply voltage is delivered by an external dc voltage source.NCP1338 vs NCP1337:When a BO condition is applied, both controllers stop. When the BO condition is removed, NCP1337 doesn't restart if the fault timer has timed out; whereas NCP1338 always restarts (if Vcc is higher than 12 V).

特性 Features

• Overvoltage Protection
• rugged design
• Internal Leading Edge Blanking
• Noise immunity
• Free-Running Borderline/Critical Mode Quasi-Resonant Operation
• Reduces EMI and capacitive losses
• Soft-Skip Mode with Minimum Switching Frequency for Standby
• reduces noise and increases efficiency in stand-by mode
• Current-Mode
• Auto-Recovery Short-Circuit Protection Independent of Auxiliary Voltage
• Brown-Out Protection
• Two Externally Triggerable Fault Comparators (one for a disable function, and the other for a permanent latch)
• Internal 4.0 ms Soft-Start
• 500 mA Peak Current Drive Sink Capability
• 130 kHz Max Frequency
• Internal Temperature Shutdown
• Direct Optocoupler Connection
• Dynamic Self-Supply with Levels of 12 V (On) and 10 V (Off)
• SPICE Models Available for TRANsient and AC Analysis
• Pb-Free Device

应用 Application

• Ac-dc Adapters for Notebooks, etc.
• Offline Battery Chargers
• Auxiliary Power Supplies (USB, Appliances, TVs, etc.)
• Consumer Electronics (DVD Players, Set-Top Boxes, TVs, etc.)

简介

NCP1338属于集成电路（IC）的ACDC转换器离线开关。由制造生产的NCP1338AC 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。