Application Note, V1.1, Oct 2007 CoolSET TM 24 V / 350 mA LED PSU Using ICE3B0365JG Power Management & Supply CoolSETTM LED Demoboard using ICE3B0365JG on Board Edition 2007-05 Published by Infineon Technologies AG 81726 Munich, Germany © 2007 Infineon Technologies AG All Rights Reserved. LEGAL DISCLAIMER THE INFORMATION GIVEN IN THIS APPLICATION NOTE IS GIVEN AS A HINT FOR THE IMPLEMENTATION OF THE INFINEON TECHNOLOGIES COMPONENT ONLY AND SHALL NOT BE REGARDED AS ANY DESCRIPTION OR WARRANTY OF A CERTAIN FUNCTIONALITY, CONDITION OR QUALITY OF THE INFINEON TECHNOLOGIES COMPONENT. THE RECIPIENT OF THIS APPLICATION NOTE MUST VERIFY ANY FUNCTION DESCRIBED HEREIN IN THE REAL APPLICATION. INFINEON TECHNOLOGIES HEREBY DISCLAIMS ANY AND ALL WARRANTIES AND LIABILITIES OF ANY KIND (INCLUDING WITHOUT LIMITATION WARRANTIES OF NON-INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY) WITH RESPECT TO ANY AND ALL INFORMATION GIVEN IN THIS APPLICATION NOTE. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. CoolSETTM LED Demoboard using ICE3B0365JG on Board CoolSETTM Revision History: 2007-10 Previous Version: 2007-05 Page Subjects (major changes since last revision) Page 11 2007-10 Update Schematics (Figure 2 and Figure 3) V1.1 V1.0 We Listen to Your Comments Any information within this document that you feel is wrong, unclear or missing at all? Your feedback will help us to continuously improve the quality of this document. Please send your proposal (including a reference to this document) to: [email protected] Application Note 3 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Table of Contents Page 1 Abstract ........................................................................................................................................................5 2 Introduction..................................................................................................................................................6 3 Application ...................................................................................................................................................7 4 CoolSET™ Third Generation of System ICs.............................................................................................8 5 TLE4305 Constant Current Regulator .......................................................................................................9 6 Power Supply Specification .....................................................................................................................10 7 Schematics.................................................................................................................................................11 8 PCB Layout ................................................................................................................................................12 9 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 Board Description .....................................................................................................................................13 Start Up .......................................................................................................................................................13 Operation Mode...........................................................................................................................................13 Snubber Network.........................................................................................................................................13 Soft Start......................................................................................................................................................13 Feedback Network (optional) ......................................................................................................................13 Peak Power Limitation (Limitation of the Primary Current) .........................................................................13 Output Section and Current Regulation via TLE4305G ..............................................................................14 Alternating Load during Operation ..............................................................................................................14 10 Conclusion .................................................................................................................................................15 11 Bill of Material ............................................................................................................................................16 12 Transformer Construction Documentation ............................................................................................17 13 Performance Data......................................................................................................................................18 13.1 Efficiency .....................................................................................................................................................18 13.2 Output Current Regulation ..........................................................................................................................19 14 14.1 14.2 14.3 Waveforms and Scope Plots ....................................................................................................................20 Start Up @ Low and High Line....................................................................................................................20 Drain Source Voltage and Current ..............................................................................................................22 Regulation Characteristic ............................................................................................................................23 15 References .................................................................................................................................................24 Application Note 4 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Abstract 1 Abstract High brightness LEDs are becoming more popular in replacing conventional incandescent lamps in terms of efficiency, reliability and space requirement. Moreover, the field of emergency lighting and advertising has been made available to LED lighting. In using an integrated off line switching regulator like CoolSETTM in combination with the current regulator TLE4305, a low cost and high efficient LED driver for multiple LEDs has been developed to drive the LEDs from an extended wide line input voltage. Application Note 5 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Introduction 2 Introduction This document introduces the isolated offline coφnstant current high line LED driver based on the CoolSET™ family. The paper contains a list of features, power supply specification, schematic, bill of material and the transformer construction documentation. Typical operating characteristics are presented at the rear of this report and consist of performance curves and scope waveforms. Introduction CoolSETTM LED Demoboard using ICE3B0365JG on Board Application 3 Application The Infineon Technologies AG proposes an isolated off line switch mode power supply (SMPS, see Figure 1) for a LED cluster used for wide line input voltage applications from VACIN = 90 V up to 270 V in flyback topology. The application is fully protected against an open loop gain (OLP), short circuit (OCP), over temperature (OTP), over voltage at the VCC stage (OVP), under voltage (UVLO) and a highly accurate power limiting in case of over load via Propagation Delay Compensation™ (patented by Infineon Technologies AG) in the whole line input voltage range. All protection features are using the auto restart mode. Optional, the application is able to drive the LEDs in a continuous load (Figure 2), or for alternating load, in that case, the LEDs are protected against surge currents during alternating loads (see Figure 3). The driver application uses the Infineon jitter system IC CoolSETTM F3 as PWM current mode controller with integrated MOSFET (CoolMOSTM) and the TLE4305G as a current regulator on the secondary side. The application is designed to drive one 350 mA high brightness LED or optional a series connection of up to 6 high brightness LEDs (350 mA) in a high efficiency. Bottom View Figure 1 LED-ICE3B0365JG Demoboard TOP View CoolSETTM LED Demoboard using ICE3B0365JG on Board CoolSET™ Third Generation of System ICs 4 CoolSET™ Third Generation of System ICs The CoolSETTM family is a smart hybrid power device combines the superior technology of the high voltage MOSFET CoolMOSTM and a PWM current mode control IC. It is designed for switched mode power supplies using a lower external component count - standard applications require only 7 external components to drive the CoolSETTM. In order to increase the reliability, the integrated control circuit offers the benefit of enhanced protection features all with auto restart (hiccup mode), an active burst mode for extreme low standby power, a high voltage start up cell, a programmable soft start and blanking window function and a frequency jittering to reduces EMI. The lowest area specific RDS(ON), a high avalanche ruggedness and the low switching losses of the CoolMOSTM increase the efficiency and improves the standby power. The integrated Propagation Delay CompensationTM (patented by Infineon Technologies) results a highly accurate power limiting in the whole line input voltage range – optimized design for a global application. Table 1 List of Integrated CoolSETTM Features Feature List CoolSETTM Device ICE3B0365JG with 67 kHz Working Frequency 650V 1 CoolMOSTM with implemented Start Up Cell Integrated active Burst Mode Function with immediate Response of Load Jumps Programmable Over Current Blanking Window for short Term Over Current Programmable Soft Start Integrated Frequency Jitter to improve the EMI Behavior Integrated Over Load Protection (OLP) with auto restart Integrated Over Current Protection (OCP) with auto restart Integrated Over Temperature (OTP) Shut Down with auto restart Integrated Open Loop Protection (OLP) with auto restart Integrated Under Voltage Lock Out (UVLO) with auto restart Integrated Propagation Delay CompensationTM and Leading Edge Blanking External Current Sense for highly accurate Power Limiting PDSO16/12 SMD Package with extended Creepage Distance 1 VDSBR at Tj = 110°C Application Note 8 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board TLE4305 Constant Current Regulator 5 TLE4305 Constant Current Regulator The TLE4305G is specifically designed to control the output voltage and the output current of a SMPS. Independent compensation networks for the voltage and the current loop can be realized by external circuitry. The device contains a high accuracy bandgap reference voltage, two operational transconductance amplifiers (OTA), an optocoupler driver output stage and a high-voltage bias circuit. The device is based on Infineons double isolated power line technology DOPL which allows producing high precision bipolar voltage regulators with breakdown voltages up to 45 V. The efficiency increases furthermore due to the very low voltage drop (only 200 mV) at the shunt resistors R28 and R29 of the TLE4305G. Application Note 9 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Power Supply Specification 6 Power Supply Specification Table 2 Power Supply Specification Description Symbol Min. Typ. Max. Units 115/230 270 VAC 380 VDC 23.6 VDC Input Section AC Input Voltage (f =16 – 400 Hz) VACIN 90 DC Input Voltage VDCIN 120 Output Section Output Voltage @ no Load VOUT Output Voltage Conditions VOUT 4.0 16.7 22.5 VDC Output Current IOUT 340 340 340 mADC Output Power Nominal POUT 1.4 5.7 7.8 W Efficiency (90 VAC) η 77 86 87 % Efficiency (270 VAC) η 63 84 85 % Environmental Ambient Temperature TA 25 °C Thermal Consideration (Temperature Increase @ nom Load and VACIN = 90V) Transformer 20 °C CoolSETTM 20 °C TLE4305 20 °C Output Diode 50 °C LED LA W57B 70 °C Output Capacitors 20 °C Application Note 10 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Schematics 7 Schematics Figure 2 Power Supply Schematic for Continuous Load (Standard) Figure 3 Power Supply Schematic for Alternating Load Application Note 11 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board PCB Layout 8 PCB Layout 24 V / 350 mA – LED-Demoboard Infineon technologies Figure 4 Power Supply PCB Layout Application Note 12 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Board Description 9 Board Description The SMPS for a LED cluster is an isolated off line discontinuous current mode (DCM) application in flyback mode using ICE3B0365JG – the smallest system IC from the CoolSETTM - F3 family. The circuit diagram in Figure 2 (standard continuous load) and Figure 3 (for alternating load) details a 24 V / 350 mA power supply which operates from an extended AC line input voltage range from 90 VAC to 270 VAC, suitable for applications requiring either an open frame supply or an enclosed application. By replacing R41 with high brightness LEDs, the application is able to drive 1 white and in additional 6 red LEDs. The efficiency of the application is above 85% - the TLE4305G regulates the current and a constant no load voltage. 9.1 Start Up After switch on the AC line input voltage, the integrated start up cell (depletion MOSFET on the CoolMOSTM inside CoolSETTM) charges the chip supply stage up to VCC = 18 V, the controller starts working. In that moment, the start up cell shuts off and is inactive during operation mode in order to increase the efficiency. 9.2 Operation Mode The IC will be supplied from the auxiliary winding N2 in forward mode, R2 and the rectifier diode D6. C13 and C14 are taking care of a sufficient VCC voltage during different operation modes from no load to nominal load operation. The chip supply voltage (VCC) of the CoolSETTM follows the AC line input voltage from 0 V up to 22.5 VDC. In case of a higher VCC than 19 V, the network Q1, R3 and D7 clamps the chip supply voltage at VDC = 19 V in order to protect the chip supply stage of CoolSETTM against over voltage. 9.3 Snubber Network A RCD snubber (R1, C12 and D5) clamps the drain source voltage below 600 V in order to prevent an avalanche breakdown of the MOSFET. 9.4 Soft Start For a soft start during a start up or an auto restart after failure case, the soft start capacitor C16 avoids stress on the MOSFET and the diode and prevents audible noise during start up. 9.5 Feedback Network (optional) Optional, a low pass filter (C17 and R5) can be set to eliminate disturbances of the signal of the optocoupler (IC2) at the feedback PIN 3 of the CoolSETTM. 9.6 Peak Power Limitation (Limitation of the Primary Current) R4 adjusts the primary current and furthermore, the shunt resistor limits the maximum power in case of over load during the whole AC input voltage range (integrated Propagation Delay Compensation, patented by Infineon Technologies AG). The accuracy of the power limitation depends only on the tolerance of the shunt (R4). Application Note 13 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Board Description 9.7 Output Section and Current Regulation via TLE4305G The voltage on the secondary side is rectified via a fast rectifier diode D21 with a low forward voltage. A low ESR Capacitor C24 buffers energy for the output stage. The output voltage is set by the voltage divider R24 and R25 to VOUT = 24 VDCmax. The chip supply voltage of the TLE4305G is rectified via diode D22. R21 (optional) and capacitor C21 perform energy buffering for the chip supply stage at PIN VS of the TLE4305G. C22 and C23 eliminate glitches on the chip supply stage. R22 and D23 ensure stable operation during no load condition (POUT = 0 W). Due to the wide output voltage range from 0 V up to 22.5 VDC, the chip supply voltage (VS) of the TLE4305G follows the line input voltage. In case of a higher VCC than 12 V, the network Q21, R23 and D24 clamps the chip supply voltage at VDC = 12 V in order to protect the chip supply stage of TLE4305G against over voltage. R26, C25 and R27, C26 are compensation networks for the output voltage and current. The current is sensed via shunt resistors R28 and R29. 9.8 Alternating Load during Operation Note: This network is only needed in case of alternating load operation e.g. changing LEDs during operation mode and not for continuous load operations. In case of alternating load, a discharge current from the output capacitor C24 is present. This current causes a surge current peak through the LEDs. This might results a damage or a destruction of the LEDs. To prevent a destruction of the LEDs, an optional surge current compensation network (R30, Q22 and Q23 in Figure 3) can be implemented to limit the discharging current from the capacitor C24. Application Note 14 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Conclusion 10 Conclusion The Infineon Technologies off line LED SMPS solution - using the Infineon current mode control system IC CoolSET™ with integrated frequency jitter and TLE4305G - was designed to give maximum protection against electrical shock from the high line input voltage, application reliability, improved EMI behavior and protects the LED against surge current during load jumps. The compact design is able to be used worldwide without any adjustments, has a high efficiency at a different numbers of LEDs, a highly accurate output current control and a very low standby power rating during no load condition (POUT = 0 W). The high integration of both Infineon devices enables a minimum of external components with a maximum of protection features for a cost saving SMPS design. Application Note 15 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Bill of Material 11 Bill of Material 350 mA / 24 V LED-SMPS with peak current limitation AC Input 90 VAC … 270 VAC Component Value Package Component Value Package K1 C21 10 µF / 40 V RM2.5 K2 C22 100 nF / 50 V 1206 F1 Fuse 1A fast Microfuse C23 100 nF / 50 V RM5 IC1 ICE3B0365JG P-DSO-16/12 C24 100 µF / 35 V RM5 low ESR IC2 SFH617A-3 C25 33 nF / 50 V 1206 IC3 TLE4305G P-DSO-8 C26 33 nF / 50 V 1206 BR1 B250S SMD L1 2.2 mH / 0.5 A SU9V D5 MURS 160 MELF-B TR2 Air Gap 0.2 mm EF16 D6 ES1D Mini-MELF N1 = 116 turns D7 ZMM 20 Mini-MELF N2 = 13 turns D21 ES1D MELF-B N3 = 25 turns D22 ES1D Mini-MELF N4 = 12 turns D23 LL4148 Mini-MELF R1 100 kΩ axial D24 ZMM 12 1206 R2 4.7 Ω 1206 D41 LA W57B R3 10 kΩ 1206 D51 LW5SG R4 2.7 Ω 1206 Q1 BC846B SOT23 R5 22 Ω axial Q21 BC846B SOT23 R21 4.7 Ω 1206 Q22 BC817 SOT23 R22 4.7 kΩ axial Q23 BSP 320S SOT223 R23 10 kΩ 1206 C1 100 nF / 250 VAC-X2 RM15 R24 33 kΩ 1206 C5 1 nF / 250 VAC-Y1 RM15 R25 3.9 kΩ 1206 C11 10 µF / 400 V RM5 R26 22 kΩ 1206 C12 1 nF / 400 V RM5 R27 22 kΩ 1206 C13 4.7 µF / 25 V RM2.5 R28 1.2 Ω 1206 C14 10 µF / 40 V RM2.5 R29 1.2 Ω 1206 C15 100 nF / 50 V 1206 R30 15 kΩ 1206 C16 470 nF / 50 V 1206 R41 39 Ω / 10 W axial C17 2.2 nF / 50 V 1206 S1 N2F4PCA Switch Application Note 16 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Transformer Construction Documentation 12 Transformer Construction Documentation 9W LED Flyback Transformator 24V/350mA-Demoboard Core: EF16/8/5 Material: N67 Coil Former: horizontal Inductivity: 1,75mH Pin 4 Pin 5 Total Air Gap: 0,2mm Peak Current: 0,4A Aux Sec 2 Pin 7 Pin 6 Pin 9 Pin 10 Sec 1 = 9Turns Sec 1 = 16Turns Pin 2 Prim Pin 1 Center leg means one layer Makrofol Primary winding Secondary winding 1 Secondary winding 2 Auxiliary winding Application Note 116 turns 0,18 mm ∅ 25 turns 0,35 mm ∅ TEX-E wire 12 turns 0,35 mm ∅ TEX-E wire 13 turns 0,18 mm ∅ spread 5 6 4 1 7 10 2 9 Bottom View: Pin Pin Pin Pin Pin 17 5 4 3 2 1 • ∙ ∙ ∙ ∙ • ∙ ∙ ∙ ∙ Pin Pin Pin Pin Pin 6 7 8 9 10 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Performance Data 13 Performance Data 13.1 Efficiency Efficiency vs. Pout 80 70 Efficiency [%] 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 Pout [W] Vacin = 90V Figure 5 Vacin = 270V Efficiency versus Output Power Figure 5 shows the efficiency (y-axis) versus output power (x-axis) of the LED SMPS at low line input voltage VACIN = 90 V and high line input voltage VACIN = 270 V for different numbers of LEDs. Application Note 18 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Performance Data 13.2 Output Current Regulation Output Current versus Output Voltage 0,4 0,35 Output Current [A] 0,3 0,25 0,2 0,15 0,1 0,05 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Output Voltage [V] Output Current Figure 6 Controlled Output Current versus Output Voltage Figure 6 shows the current regulation characteristic of the output stage. The output voltage (x-axis) rises with increasing load from POUTmin until maximum load (1 white and add. 6 red high brightness LEDs). While exceeding maximum load (respective maximum output voltage) the TLE4305G decreases the current (y-axis) down to zero and holds the output voltage stable at the maximum level of VOUT = 23.6 V. Application Note 19 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Waveforms and Scope Plots 14 Waveforms and Scope Plots 14.1 Start Up @ Low and High Line Figure 7 and Figure 8 are showing a typical start up from plug in the AC line input voltage till working mode. The chip supply voltage VCC (Ch1) will be charged up via the implemented start up cell to the VCCON threshold @ typ. 18 V. If the chip supply voltage exceeds this threshold, the start up cell is inactive. Now, the control IC starts working and switches the gate drive on. In the soft start phase - the soft start voltage (Ch3) rises from 1 V up to 3 V to limit the primary current via duty cycle limitation. If the soft start voltage reach the operation threshold at typ. 3.2 – 3.6 V (sawtooth wave form) and the output voltage (Ch4) reaches the working level, the feedback voltage (Ch2) decreases from its reference voltage down to the operation level dependent from the load at the output. Application Note 20 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Waveforms and Scope Plots Start UP: VACIN = 90 V (High Resolution Mode) Ch1: VCC (Chip Supply Voltage PIN 11 to GND PIN 12) Ch2: VFB (Feedback Voltage PIN 31 to GND PIN 12) Ch3: VSS (Softstart Voltage PIN 2 to GND PIN 12) Ch4: VOUT (Output Voltage C24 to TLE GND) Figure 7 Startup @ Low and High AC Line Input Voltage and Nominal Load Start UP: VACIN = 90 V (High Resolution Mode) Ch1: VCC (Chip Supply Voltage PIN 11 to GND PIN 12) Ch2: VFB (Feedback Voltage PIN 31 to GND PIN 12) Ch3: VSS (Softstart Voltage PIN 2 to GND PIN 12) Ch4: VOUT (Output Voltage C24 to TLE GND) Figure 8 Start UP: VACIN = 270 V (High Resolution Mode) Ch1: VCC (Chip Supply Voltage PIN 11 to GND PIN 12) Ch2: VFB (Feedback Voltage PIN 31 to GND PIN 12) Ch3: VSS (Softstart Voltage PIN 2 to GND PIN 12) Ch4: VOUT (Output Voltage C24 to TLE GND) Start UP: VACIN = 270 V (High Resolution Mode) Ch1: VCC (Chip Supply Voltage PIN 11 to GND PIN 12) Ch2: VFB (Feedback Voltage PIN 31 to GND PIN 12) Ch3: VSS (Softstart Voltage PIN 2 to GND PIN 12) Ch4: VOUT (Output Voltage C24 to TLE GND) Startup @ Low and High AC Line Input Voltage and light Load Application Note 21 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Waveforms and Scope Plots 14.2 Drain Source Voltage and Current RUN Mode: VACIN = 90 V (High Res. Mode) @ nom. Load Ch1: VSense (Sense Voltage @ CoolSET PIN 4 to GND PIN 12) Ch2: VOUT (Output Voltage @ C24 to TLE GND PIN 5) Ch3: IOUT (Output Current @ through Golden Dragon Diode) Ch4: VDS (Drain Source Voltage @ Transformer PIN 2) Figure 9 Drain Source Voltage and Current during Normal Operation @ nom. Load RUN Mode: VACIN = 90 V (High Res. Mode) @ light Load Ch1: VSense (Sense Voltage @ CoolSET PIN 4 to GND PIN 12) Ch2: VOUT (Output Voltage @ C24 to TLE GND PIN 5) Ch3: IOUT (Output Current @ through Golden Dragon Diode) Ch4: VDS (Drain Source Voltage @ Transformer PIN 2) Figure 10 RUN Mode: VACIN = 270 V (High Res. Mode) @ nom. Load Ch1: VSense (Sense Voltage @ CoolSET PIN 4 to GND PIN 12) Ch2: VOUT (Output Voltage @ C24 to TLE GND PIN 5) Ch3: IOUT (Output Current @ through Golden Dragon Diode) Ch4: VDS (Drain Source Voltage @ Transformer PIN 2) RUN Mode: VACIN = 270 V (High Res. Mode) @ light Load Ch1: VSense (Sense Voltage @ CoolSET PIN 4 to GND PIN 12) Ch2: VOUT (Output Voltage @ C24 to TLE GND PIN 5) Ch3: IOUT (Output Current @ through Golden Dragon Diode) Ch4: VDS (Drain Source Voltage @ Transformer PIN 2) Drain Source Voltage and Current during Normal Operation @ light Load Application Note 22 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board Waveforms and Scope Plots 14.3 Regulation Characteristic Note: (optional, not needed for continuous load operation): In case of alternating load, a discharge current from the output capacitor C24 is present. This current causes a surge current peak (Ch4) through the LEDs. This surge current will be compensated with the network (R30, Q22 and Q23) in order to protect the LEDs. Figure 1111 shows regulation characteristic of this network regarding the surge current through the LEDs in two states: alternating load from nominal and no load into light load condition with out shut off of the application (feedback Ch2 and soft start voltage Ch3 are in its working levels). Load Jump from nominal Load to light Load Ch1: VOUT (Output Voltage @ C24 to TEL GND PIN 5) Ch2: VFB (Feedback Voltage @ CoolSET PIN 3 to GND PIN 12) Ch3: VSoft Start (Soft Start Voltage @ CoolSET PIN 2 to GND PIN 12) Ch4: IOUT (Output Current @ through Diodes Golden Dragon) Figure 11 Load Jump from nominal Load to light Load Ch1: VOUT (Output Voltage @ C24 to TEL GND PIN 5) Ch2: VFB (Feedback Voltage @ CoolSET PIN 3 to GND PIN 12) Ch3: VSoft Start (Soft Start Voltage @ CoolSET PIN 2 to GND PIN 12) Ch4: IOUT (Output Current @ through Diodes Golden Dragon) Load Jump Behavior Application Note 23 V1.1, 2007-10 CoolSETTM LED Demoboard using ICE3B0365JG on Board References 15 References [1] ICE2AXXX for OFF-Line Switch Mode Power Supplies Application Note, Infineon Technologies [2] CoolSETTM – III Off-line SMPS Current Mode Controller with High Voltage CoolMOSTM on Board Datasheet, Infineon Technologies [3] Application Note 24 V1.1, 2007-10 www.infineon.com Published by Infineon Technologies AG