ncp1337主要特性：
• free−running borderline/critical mode quasi−resonant operation
• current−mode
• soft−skip mode with minimum switching frequency for standby
• auto−recovery short−circuit protection independent of auxiliary voltage
• overvoltage protection
• 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 leading edge blanking
• 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
• these are pb−free devices*
ncp1337应用：
• 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.)
图1. ncp1337内部方框图
ncp1337adapgevb方案介绍：
this design using ncp1337 offers a perfect solution for portable dvd, lcd tv, or monitor and notebook adapter applications. this adapter provides effective protection functions such as over-load protection, over-voltage protection, shortcircuit protection and brown-out protection. thanks to the quasi-resonant operation and synchronous rectifier, this adapter has high efficiency and improved emi performance. the standby consumption is lower because of the cycle skipping and soft ripple mode.
ncp1337adapgevb方案原理图：
图2. ncp1337adapgevb方案原理图
ncp1562-100wgevb方案材料清单：
pcb元件布局图：
onsemi公司的ncp1337是一款结合电流模式调节器和退磁检测器的芯片，以充分确保边界线/临界传导模式在任何负载/传输线条件连同最低漏电压开关（准-谐振操作）。因为soxyless概念，变压器铁心重置检测在内部完成，没有使用任何外部信号。根据cispr-22 emi限制标准，内部频率被限制于130khz，防止控制器操作达到150khz。该芯片具有过载保护重启功能，一旦过载，设备会自动重启恢复。主要介绍ncp1337芯片、芯片特性、应用方向及内部结构图。本文介绍了采用ncp1337芯片作为主芯片的60w参考设计方案，给出该方案的介绍、方案原理图、pcb制板图及元器件清单列表。
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