供应PWM电流模式控制器1377B

NCP1377, NCP1377B
PWM Current-Mode
Controller for Free-Running
Quasi-Resonant Operation

IC型号：NCP1377BDR2G
IC描述：控制器的PWM Current−Mode Free−Running Quasi−Resonant操作
该NCP1377结合了真正的电流模式调制器和一个磁检测器，
确保充分的边界线/临界传导模式/线路条件以及在任何负载漏电压开关(Quasi−Resonant操作）.
由于其固有的跳周期能力，控制器进入突发模式只要电力需求低于预定水平.
随着这种情况在低峰值电流，无噪音，可以听到声音.对于NCP1377,
内部8.0ms定时器防止free−run频率超过100千赫（因此低于150千赫CISPR−22 EMI开始限制），
而跳过调整lets用户能力选择频率在哪个突发折返发生.对于NC1377B,
内部定时器时间减少到3.0ms让行动于更高的频率（高达300千赫）.
变压器磁芯去磁检测是通过一个辅助蜿蜒其中，通过专用引脚带，
也可实现快速过电压保护(OVP).一旦OVP被检测到，IC永久闭锁.
该1377具有采样时间4.5ms而这是1.5ms为B版本.
该NCP1377还具有高效的保护设计电路其中，
在过流情况的存在，关闭输出脉冲并进入安全突发模式，
试图重新启动.一旦故障已消失，器件auto−recovers.
最后一内部1.0 msSoft−Start消除了传统的启动压力

特点：
Free−Running边界线/临界操作模式Quasi−Resonant锁存过压保护
Auto−Recovery通过Short−Circuit交叉UVLO保护外部锁存触发，
通过过热信号e.g.Current−Mode可调跳周期能力内部1.0 ms
Soft−Start内部温度关机内置前沿消隐500 mA 峰值电流源/吸收能力
根据12.5 V（ON）和7.5 V（民）电压等级分离直接连接光耦SPICE模型
瞬态可供分析内部最小T关Pb−Free包可用
 
典型应用
为笔记本电脑，AC−DC适配器etc.
离线电池充电器
消费电子(DVD运动员，Set−Top盒，TVs, etc.)
辅助电源(USB,电器，TVs, etc.)

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 8.0 s timer prevents the free-run frequency to
exceed 100 kHz (therefore below the 150 kHz CISPR-22 EMI
starting limit), while the skip adjustment capability lets the user
select the frequency at which the burst foldback takes place. For
NC1377B, the internal timer duration is reduced to 3.0 s to allow
operation at higher frequencies (up to 300 kHz).
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
4.5 s whereas it is 1.5 s 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 restart. Once the default
has gone, the device auto-recovers. Finally an internal 1.0 ms
Soft-Start eliminates the traditional startup stress.
Features
•Free-Running Borderline/Critical Mode Quasi-Resonant Operation
•Latched Overvoltage Protection
•Auto-Recovery Short-Circuit Protection Via UVLO Crossover
•External Latch Triggering, e.g. Via Overtemperature Signal
•Current-Mode with Adjustable Skip Cycle Capability
•Internal 1.0 ms Soft-Start
•Internal Temperature Shutdown
•Internal Leading Edge Blanking
•500 mA Peak Current Source/Sink Capability
•Under Voltage Lockout Level of 12.5 V (On) and 7.5 V (Min)
•Direct Optocoupler Connection
•SPICE Models Available for TRANsient Analysis
•Internal Minimum TOFF
•Pb-Free Packages are Available
Typical Applications
•AC-DC Adapters for Notebooks, etc.
•Offline Battery Chargers
•Consumer Electronics (DVD Players, Set-Top Boxes, TVs, etc.)
•Auxiliary Power Supplies (USB, Appliances, TVs, etc.)