ST公司的VIPER11是節能高壓離線轉換器，集成了雪崩電壓800V的MOSFET和PWM電流模式控制，允許可以使用超寬的VAC輸入電壓，嵌入了HV起動和檢測FET，漏極電流限制保護，電源電壓4.5V-30V，能滿足最嚴格的節能標準，支持反激，降壓和降壓升壓轉換器，其集成的HV起動，檢測FET，誤差放大器和抖動振蕩器可以使用最少外接元件實現完整的應用方案。主要用在家用電器，家庭自動化，工業，消費類電子和照明的低功率SMPS以及低功率適配器。本文介紹了VIPER11主要特性，框圖，基本應用電路和多種應用電路，以及評估板STEVAL-ISA195V1主要特性和電指標，電路圖，材料清單和PCB設計圖。

The device is a high voltage converter smartlyintegrating an 800 V avalanche-rugged powerMOSFET with PWM current mode control. Thepower MOSFET with 800 V breakdown voltageallows the extended input voltage range to beapplied，as well as the size of the DRAIN snubbercircuit to be reduced. This IC meets the moststringent energy-saving standards as it has verylow consumption and operates in pulse frequency modulation under light load. The design offlyback， buck and buck boost converters is supported. The integrated HV startup， sense-FET， error amplifier and oscillator with jitter allowa complete application to be designed with theminimum number of components.

VIPER11主要特性：

? 800 V avalanche-rugged power MOSFETallowing ultra wide VAC input range to be covered

? Embedded HV startup and sense-FET

? Current mode PWM controller

? Drain current limit protection

– 480 mA （VIPER114）

– 590 mA （VIPER115）

? Wide supply voltage range： 4.5 V to 30 V

? Minimized system input power consumption：

– Less than 10 mW at 230 VAC in no-loadcondition

– Less than 400 mW at 230 VAC with 250mW load

? Jittered switching frequency reduces the EMIfilter cost：

– 30 kHz ± 7% （type X）

– 60 kHz ± 7% （type L）

? Embedded E/A with 1.2 V reference

? Protections with automatic restart:overload/short-circuit （OLP）， line or output OVP，max. duty cycle counter， VCC clamp

? Pulse-skip protection to prevent flux- runaway

? Embedded thermal shutdown

? Built-in soft-start for improved system reliability

VIPER11應用：

? Low power SMPS for home appliances， homeautomation， industrial， consumer， lighting

? Low power adapters

圖1.VIPER11框圖

圖2.VIPER11基本應用電路圖

圖3.VIPER11反激轉換器（非隔離）框圖

圖4.VIPER11帶線路OVP的反激轉換器（非隔離）框圖

圖5.VIPER11反激轉換器（隔離）框圖

圖6.VIPER11初級邊穩壓器的隔離反激轉換器框圖

圖7.VIPER11降壓轉換器正輸出框圖

圖8.VIPER11降壓-升壓轉換器負輸出框圖

評估板STEVAL-ISA195V1

STEVAL-ISA195V1： 5 V/1.8 W 30 kHz buck demo with the VIPer11 The STEVAL-ISA195V1 is a 5 V - 0.36 A power supply set in buck topology using the new VIPER11 off-line high voltageconverter by STMicroelectronics， specifically developed for non-isolated SMPS.

評估板STEVAL-ISA195V1主要特性：

? An 800 V avalanche rugged power section

? Integrated HV-start-up current generator

? Onboard soft-start

? PWM operation at 30 kHz with frequency jittering for lower EMI

? Transconductance error amplifier with 1.2 V ±2% reference voltage

? Self-supply option to avoid auxiliary winding and bias components

Thanks to the advanced light load management and ultra-low consumption of the VIPER11 internal blocks， the demo boardinput power consumption in no-load conditions can be reduced to less than 20 mW @230 VAC， and the most stringent energysaving regulations in terms of active mode and light load efficiency can be fulfilled. IC protection includes：

? Pulse skip mode to avoid flux-runaway during start-up

? Delayed overload shutdown for safe fault condition management

? Max. duty cycle counter

? Thermal shutdown

? Input overvoltage

All protections （except pulse skip mode） involve auto-restart mode.

圖9.評估板STEVAL-ISA195V1外形圖

評估板STEVAL-ISA195V1電指標：

圖10.評估板STEVAL-ISA195V1電路圖

評估板STEVAL-ISA195V1材料清單：

圖11.評估板STEVAL-ISA195V1 PCB完整圖

圖12.評估板STEVAL-ISA195V1 PCB設計圖：左：頂層布局;右：底層布局