TNY253/254/255超小型开关PDF下载
TinySwitch系列将700V功率MOSFET、晶振、高压开关电流源、限流和热关断电路集于一体，以其突破性设计为用户提供0~10W的成本最低和高效率离线式开关电源。265VAC输入时，其空载功耗仅80mW。使用简单的开/关控制电路，无需回路补偿。
TNY253和TNY254的44KHz开关频率减少EMI，能以一个简单的缓冲箝位电路来限制漏极的尖峰电压，而且功率在5W以下时可以采用低成本的EE16磁芯变压器。TNY253与TNY254的不同之处仅在于其流限更低，这降低了其在2.5W以下应用中的输出短路电流。
TNY255的开关频率采用更高的130KHz，能以同样的廉价EE16磁芯为如次级采用三相绝缘线的大多数应用中就不需要绝缘带/端空。这简化了变压器结构，降低了成本。TinySwitch的启动和工作能量由漏极电压提供，无需变压器偏置绕组及相关电路。
TNY253/254/255的应用
TNY254P制作手机充电器电路
TNY253/254/255简述
Lowest Cost, Low Power Switcher Solution
• Lower cost than RCC, discrete PWM and otherintegrated/hybrid solutions
• Cost effective replacement for bulky linear adapters
• Lowest component count
• Simple ON/OFF control – no loop compensation devices
• No bias winding – simpler, lower cost transformer
• Allows simple RC type EMI filter for up to 2 W from universal input or 4 W from 115 VAC input Extremely Energy Efficient
• Consumes only 30/60 mW at 115/230 VAC with no load
• Meets Blue Angel, Energy Star, Energy 2000 and 200 mW European cell phone requirements for standby
• Saves $1 to $4 per year in energy costs (at $0.12/kWHr)compared to bulky linear adapters
• Ideal for cellular phone chargers, standby power supplies for PC, TV and VCR, utility meters, and cordless phones.High Performance at Low Cost
• High voltage powered – ideal for charger applications
• Very high loop bandwidth provides excellent transientresponse and fast turn on with practically no overshoot
• Current limit operation rejects line frequency ripple
• Glitch free output when input is removed
• Built-in current limit and thermal protection
• 44 kHz operation (TNY253/4) with snubber clamp reduces EMI and video noise in TVs & VCRs
• Operates with optocoupler or bias winding feedback
Description
The TinySwitch family uses a breakthrough design to provide the lowest cost, high efficiency, off-line switcher solution in the 0 to 10 W range. These devices integrate a 700 V power MOSFET, oscillator, high voltage switched current source, current limit and thermal shutdown circuitry. They start-up and run on power derived from the DRAIN voltage, eliminating the need for a transformer bias winding and the associated circuitry.
And yet, they consume only about 80 mW at no load, from 265 VAC input. A simple ON/OFF control scheme also eliminates the need for loop compensation.
The TNY253 and TNY254 switch at 44 kHz to minimize EMI and to allow a simple snubber clamp to limit DRAIN spike voltage. At the same time, they allow use of low cost EE16 core transformers to deliver up to 5 W. The TNY253 is identical to TNY254 except for its lower current limit, which reduces output short circuit current for applications under 2.5 W.
TNY255 uses higher switching rate of 130 kHz to deliver up to 10 W from the same low cost EE16 core for applications such
as PC standby supply. An EE13 or EF13 core with safety spaced bobbin can be used for applications under 2.5 W.
Absence of a bias winding eliminates the need for taping/ margins in most applications, when triple insulated wire is used
for the secondary. This simplifies the transformer constructionand reduces cost.
