Power IntegrationsInnoSwitch3－MX 45W多輸出電源參考設計DER－635

Power Integrations公司的InnoSwitch3－MX是最新的反激隔離開關系列,組合了初級FET,初級控制器,用于同步整流的次級控制器,以及高速通信技術,不需要光耦合器;而InnoSwitch3-MX接收來自InnoMux集成電路的控制信息,能單獨測量每個輸出的負荷要求,指導InnoSwitch3-MX開關為每個輸出提供正確的輸出量,以維持電流或電壓的精確管理,這就消除了以前常見的負載和交叉調節.因此,InnoSwitch3-MX的架構集成了初級和次級控制器,大大地簡化多個輸出電源開發和制造,特別是那些緊湊外殼和高效率要求的多輸出電源.主要用在滿足能量之星8和CEC的監視器和LED電視機(TV).本文介紹了InnoSwitch3-MX產品亮點,初級控制器框圖和次級控制器框圖,以及采用InnoMUXTMIMX111U和InnoSwitchTM3-MX INN3468C的有兩個 CV和一個CC的45W多輸出反激轉換器的參考設計DER-635主要指標,高等級電路圖,以及參考設計DER-635電路圖,材料清單和變壓器電路圖,建造圖,連接框圖和PCB設計圖.

The InnoSwitch3-MX dramatically simplifies the development andmanufacturing of multiple output power supplies, particularly those incompact enclosures or with high efficiency requirements. TheInnoSwitch3-MX architecture is revolutionary in that the devicesincorporate both prIMAry and secondary controllers, with senseelements and a safety-rated feedback mechanism into a single IC.

Close component proximity and innovative use of the integratedcommunication link, FluxLink, permit accurate control of a secondarysidesynchronous rectification MOSFET with Quasi-Resonant switchingof primary integrated high-voltage switch to maintain high efficiencyacross the entire load range.

This version of InnoSwitch3 is intended to be used with InnoMux formultiple output, single-stage power supplies for monitors and TVs.This enables very high system efficiency on a small PCB foot print.

The InnoSwitch3-MX combines a high-voltage power switch, alongwith both primary-side and secondary-side controllers in one device.

The InnoSwitch3-MX is intended to be paired with an InnoMuxcontroller.The InnoSwitch3-MX architecture incorporates a novel inductivecoupling feedback scheme using the package leadframe and bondwires to provide a safe, reliable, and low-cost means to accuratelycommunicate power requests from the InnoMux controller to theprimary controller.

The primary controller on InnoSwitch3-MX is a quasi-resonant (QR)flyback controller that has the ability to operate in continuousconduction mode (CCM). The controller uses a variable currentcontrol scheme. The primary consists of a jitter oscillator; a receivercircuit magnetically coupled to the secondary controller, a currentlimit controller, 5 V regulator on the PRIMARY BYPASS pin, audiblenoise reduction engine, bypass overvoltage detection circuit, alossless input line sensing circuit, current limit selection circuitry,overvoltage protection, leading edge blanking, secondary outputdiode / SR MOSFET short protection circuit and a 650 V / 725 V /750 V power switch.

The secondary controller consists of a transmitter circuit that is magnetically coupled to the primary receiver, synchronous rectifier (SR) MOSFET driver, timing functions and a host of integrated protection features.

InnoSwitch3-MX產品亮點:

Based on InnoSwitch3
? Partner IC to InnoMux
? High efficiency across full load range
? Incorporates a multi-mode Quasi-Resonant (QR) / CCM flybackcontroller, 650 V or 725 V switch, secondary-side sensing andsynchronous rectification driver
? Integrated FluxLink?, HIPOT-isolated, feedback link
? Instantaneous transient response ±5% CV with 0%-100%-0%load step
EcoSmart? – Energy Efficient
? Easily meets all global energy efficiency regulations
? Low heat dissipation
Advanced Protection / Safety Features
? Primary sensed output OVP
? Open SR FET gate detection
? Hysteretic thermal shutdown
? Input voltage monitor with accurate brown-in/brown-out andovervoltage protection
Full Safety and Regulatory Compliance
? Reinforced insulation
? Isolation voltage >4000 VAC
? 100% production HIPOT compliance testing
? UL1577 and TUV (EN60950) safety approved
? Enables designs that have “A” performance criteria for EN61000-4suite of test standards, including EN61000-4-2, 4-3 (30 V/m), 4-4,4-5, 4-6, 4-8 (100 A/m) and 4-9 (1000 A/m)
Green Package
? Halogen free and RoHS compliant
InnoSwitch3-MX應用:
? Use with InnoMux for Energy Star 8 and CEC for monitors and TVs

圖1.InnoSwitch3-MX初級框圖

圖2.InnoSwitch3-MX次級框圖

圖3. InnoSwitch3-MX典型應用/性能框圖

采用InnoMUXTMIMX111U和InnoSwitchTM3-MX INN3468C的有兩個CV和一個CC的45W多輸出反激轉換器參考設計DER-635

This engineering report describes a PSU for a LED TV. This Switch Mode Power Supply (SMSP), utilizes InnoSwitch3-MX and InnoMUX from the InnoSwitch family. It has a 5 V / 1 A and 12 V / 1.25 A outputs and 25 W output providing power to one CC driver intended for LED back-light in the TV panel. The total current hrough the LED strings is controlled from 0mA to 650mA by an analogue signal (ADIM) with a full scale of 1.5 V. The total maximum power output is 45W and the input voltage range is 90 VAC to 265 VAC.

The new architecture uses a multiplexed system where only one transformer as shown in Figureure4. For each switching cycle, the energy stored in the transformer during the primary conduction interval is delivered to only one of the converter ’s main outputs (CV1, CV2 or LED). Leveraging only a single magnetic component, the controller directs the energy flow as needed to all outputs based on respective loading requirements, thus keeping each output accurately controlled. This multiplexing is achieved by gating the steering FET Q2 or Q4 appropriately. If energy pulse needs to be delivered to the CV1 output, Q2 it turned ON prior to the end of the primary conduction interval. Same process for CV2 with Q4 steering FET, otherwise If Q1 and Q4 are held OFF the energy will be delivered to the LED output via the rectification diode D3.

InnoSwitch3-MX and InnoMUX are industry first AC/DC ICs chipset with isolated, safety rated integrated feedback. In addition there are a built in synchronous rectification for >90% efficiency at nominal AC input.

The control chipset incorporates isolated feedback and communication channels while implementing All the benefits of secondary-side control with the simplicity of primary-side regulation.

There are a few important safety feature, such as
? Output overvoltage protection (OVP), which eliminates the need for fault protection optocoupler.
? Accurate thermal protection with hysteretic shutdown.
? Input voltage monitor with accurate brown-in/brown-out and overvoltage protection.

The new architecture goals are to achieve tight cross regulation across multiple outputs and high overall efficiency while simplifying the overall system by removing conventional DC-DC converter post-regulation stages. This one level converter enable to reduce board size significantly and part count shrinking in about 50% compare to conventional converter that require more than one extra converter level. In addition with this high level of integration we gain all the benefits of InnoSwitch protections from shorts to OVUV in the input or in the outputs terminals.

參考設計DER-635主要特性:

?Unique single stage conversion; multiple output; Flyback architecture enabling:
? High Efficiency across the universal line range
? Energy Star 8.0 efficiency compliance
? High accuracy independently regulated 5V/1A and 12V/1.25A CV outputs with extremely fast load transient response of 150μsec and 250μsec respectively.
? One CC LED output with wide string voltage range of 30-50V makes it suitable for wide range of Televisions applications.
? Configurable for
oanalogue dimming mode
oStraight PWM dimming mode
oFiltered PWM dimming mode and
oHybrid dimming mode.
?