Application Note, V1.3, 03 July 2013 Application Note EVALHS-ICE1HS01G 200W SMPS Evaluation Board using LLC Half Bridge Resonant Controller ICE1HS01G/ICE1HS01G-1 Power Management & Supply N e v e r s t o p t h i n k i n g . Published by Infineon Technologies AG 81726 Munich, Germany © 2007 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, 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. 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. 200W 2 outpus Demoboard using ICE1HS01G/-1 on board Revision History: Previous Version: Page 3 July 2013 V1.2 Subjects (major changes since last revision) Add alternative IC ICE1HS01G-1 V1.3 200W SMPS Evaluation Board using LLC Half Bridge Resonant Controller ICE1HS01G/-1 License to Infineon Technologies Asia Pacific Pte Ltd Eric Kok Mao Mingping He Yi Jeoh Meng kiat 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] AN-PS0038 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 Table of Contents 1 Introduction ........................................................................................................ 5 2 Evaluation Board ............................................................................................... 5 3 ICE1HS01G Features ......................................................................................... 5 4 Technical Specification ..................................................................................... 6 5 Circuit Description............................................................................................. 6 6 Circuit Operation ............................................................................................... 7 6.1 Startup Operation.......................................................................................................................... 7 6.2 Output Voltage Regulation ........................................................................................................... 8 7 Protection Features ........................................................................................... 9 7.1 Vcc Under Voltage Protection ..................................................................................................... 9 7.2 Over Current Protection ............................................................................................................... 9 7.3 Over Load Protection.................................................................................................................... 9 7.4 Mains Under Voltage Protection ................................................................................................ 11 7.5 Open Load Protection................................................................................................................. 11 8 Circuit Diagram and Components List .......................................................... 12 8.1 Schematics .................................................................................................................................. 12 8.2 PCB Layout .................................................................................................................................. 13 8.3 Components List ......................................................................................................................... 14 9 Electrical Test Results .................................................................................... 16 9.1 Efficiency Measurements ........................................................................................................... 16 9.2 Zero Voltage Switching .............................................................................................................. 17 9.3 Soft Start ...................................................................................................................................... 18 9.4 Mains Under Voltage Protection ................................................................................................ 18 9.5 Output Short Circuit Protection ................................................................................................. 19 9.6 9.6.1 9.6.2 9.7 Over Load Protection.................................................................................................................. 20 Adjustable blanking time ............................................................................................................... 20 Adjustable restart time .................................................................................................................. 20 Burst Mode Operation at No Load............................................................................................. 21 9.8 Dynamic Load Response ........................................................................................................... 21 10 Transformer Constructure .............................................................................. 22 10.1 Mains Transformer ...................................................................................................................... 22 10.2 Pulse Transformer ...................................................................................................................... 23 11 References ....................................................................................................... 24 Application Note 4 3 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 1 Introduction The demoboard described in this paper is a 200W half bridge LLC resonant converter using LLC controller ICE1HS01G/-1, which is a 8-pin LLC controller developed by Infineon Technologies. ICE1HS01G/-1 is specially designed for applications of switch mode power supplies used in LCD / PDP TV, AC/DC adapter and Audio system. ICE1HS01G/-1 is a 8-pin controller IC in DSO package and it is very flexible to implement in the PCB. Furthermore, it includes all the necessary control strategies for HB LLC resonant converter. ICE1HS01G/-1 allows the designer to select suitable operation frequency range by programming the oscillator with an external resistor. The built-in soft-start function is available to limit both the inrush current and the overshoot of output voltage. In addition, ICE1HS01G/-1 can perform all the necessary protection functions in HB LLC resonant converters. All those functions make ICE1HS01G/-1 an outstanding product for HB LLC resonant converter in the market. 2 Evaluation Board Figure 1. 200W half bridge LLC resonant converter demoboard using ICE1HS01G/-1 The 200W half bridge LLC resonant converter demoboard with ICE1HS01G/-1 is implemented as shown in Figure 1. The LLC stage’s full load efficiency reaches 94.8%. 3 ICE1HS01G/-1 Features Maximum 600kHz switching frequency Adjustable minimum switching frequency with high accuracy 50% duty cycle Mains input under voltage protection with adjustable hysteresis Two levels of overcurrent protection: frequency shift and latch off Open-loop/over load protection with extended blanking time Built-in digital and nonlinear softstart Adjustable restart time during fault protection period Application Note 5 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 4 Technical Specification The specification of this 200W LLC demoboard is listed as following table. Normal Input AC voltage 280Vac Normal DC bulk voltage 380Vdc Mains under voltage protection point 285Vdc Auxiliary power supply for IC VCC 15Vdc Normal output full load 24V/6A, 12V/5A Switching frequency 95kHz @ 24V/6A,12V/5A and 380Vdc input Table 1. Demoboard technical specification 5 Circuit Description In actual application, the LLC stage is used to connect to a front-end PFC pre-regulator. In this demoboard, in order to simplify and speed up the feature evaluation of the LLC controller, the conventional bridge rectifier BR100 without the PFC circuit, is employed to supply the high input DC voltage for the cascading LLC stage. Around 280Vac input voltage is used to feed this demboard and there would have 380Vdc across the bulk capacitor C100 accordingly. The AC line input side comprises the input fuse FUSE100 as overcurrent protection. The X2 Capacitors CX100, CX101 and Choke L101 and Y1 capacitors CY100 and CY101 forms a main filter to minimize the feedback of RFI into the main supply. NTC resistor RT100 is placed in series with input to limit the initial peak inrush current. After the bridge rectifier BR100, together with a smoothing capacitor C100, a voltage of 300Vdc to 400 Vdc is provided (depending on mains input voltage) to simulate the real operation condition with front end PFC pre_regulator. Also, the bulk capacitor C100 can be directly connected to an external DC power supply, thus the 380Vdc can be obtained. This measure makes sense when the customers want to evaluate the LLC stage’s efficiency. The second stage is a half bridge LLC resonant converter, operating in zero voltage switching mode. The controller ICE1HS01G/-1 is a 8 pin LLC controller, which incorporates the necessary functions to drive the half bridge’s high side and low side MOSFETs (Q100 and Q101) by a 50% duty cycle with dead time. The switching frequency can be changed by ICE1HS01G/-1 to regulate the output voltage against the load and input voltage variations. During operation, the primary MOSFETs Q100 and Q101 are turned-on under ZVS condition and the secondary rectifier diodes D100~D103 are turned-on and turned-off under ZCS condition. Hence high power conversion efficiency can be achieved. The Driver Module can be implemented by cost-effective pulse transformer. As shown in Figure 7, Pulse transformer TR200 is used to transmit the driver signal to MOSFETs for isolation purpose. The mains transformer TR100 uses the magnetic integration approach, incorporating the resonant series and shunt inductances. Thus, no additional external coils are needed for the resonance. The transformer configuration chosen for the secondary winding is center-tapped, and the output rectifiers D100~D103 are schottky type diodes, in order to limit the power dissipation. In case of a short circuit, the current flowing through the primary winding is detected by the lossless circuit (C106, C111, D104, D105, R102, and R107) and the resulting signal is fed into CS Pin. In case of overload, the voltage on CS pin will exceed an internal threshold 0.8V that triggers a protection mode which keeping the current flowing in the circuit at a safe level. In addition, the blanking time and the restart time can be adjusted by external components. Application Note 6 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 6 Circuit Operation 6.1 Startup Operation The controller ICE1HS01G/-1 targets at applications with auxiliary power supply. In most cases, a front-end PFC pre-regulator with a PFC controller is used in the same system. After IC supply voltage is higher than 12V, and if the voltage on VINS pin is higher than 1.25V, IC will start switching with soft start. The soft start function is built inside the IC with a digital manner. During softstart, the switching frequency of the MOSFET is controlled internally by changing the current ISS instead of the feedback signal from FB pin. The charging current ISS during soft start, which determines the switching frequency, is reduced step by step as shown in product datasheet [1]. The maximum duration of softstart is 32ms with 1ms for each step. Figure 2 illustrates the actual switching frequency VS start time when RFMIN=25kohm. During softstart, the frequency starts from 209 kHz, and step by step drops to normal operation point. Figure 2. Switching frequency during softstart @ RFmin=25kohm Figure 3. Soft start 1st step switching frequency VS RFmin Application Note 7 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 The soft start 1st step switching frequency (maximum frequency during softstart) is closely related to the minimum switching frequency fixed by external RFmin resistance. Figure 3 illustrates the relationship between the 1st step frequency and RFmin. During soft start, the overload protection is disabled because FB voltage is high. 6.2 Output Voltage Regulation The minimum switching frequency is a very important factor to guarantee the output voltage regulation at low line input and full load condition for LLC topology. ICE1HS01G/-1 allows the minimum switching frequency to be programmed by connecting an external resistor RFMIN between FMIN pin and ground. The FMIN pin provides a precise 1.5V reference voltage. The resistor RFMIN, connected from FMIN pin to GND, determines the current (IFMIN) flowing out of FMIN pin. Around one-tenth of IFMIN is defined as the minimum charging current (Ichg_min), which in turn defines the minimum switching frequency. The maximum switching frequency during normal operation and the switching frequency variation range during soft start and over current protection are all related to this current flowing out of FMIN pin, which is discussed in the product datasheet [1]. Figure 4. Minimum switching frequency VS RFMIN The output load information is fed into the controller through feedback voltage VFB. Inside the IC, the feedback (FB) pin is connected to the 5V voltage source through a pull-up resistor RFB. Outside the IC, this pin is connected to the collector of opto-coupler. Normally, a ceramic capacitor CFB can be put between this pin and ground for signal smoothing purpose. The CFB at the same time is used to determine the extended blanking time for over load protection, which will be discussed in section 7.3. If the output load is increased and consequently VFB is higher, ICE1HS01G/-1 will reduce the switching frequency to regulate the output voltage and vice versa. The regulation of switching frequency is achieved by changing the charging current IFB. The relationship between IFB and VFB can be found in product datasheet [1]. The effective range of feedback voltage VFB is from 1V to 4V. Figure 5 graphs the relationship between the actual switching frequency and feedback voltage VFB when RFMIN=25kohm. Application Note 8 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 Figure 5. Switching frequency VS feedback @ RFmin=25kohm 7 Protection Features 7.1 Vcc Under Voltage Protection The controller ICE1HS01G/-1 is targetting at applications with auxiliary power supply. In most cases, a frontend PFC pre-regulator with a PFC controller is used in the same system. The controller starts to operate when the supply voltage VCC reaches the on-threshold, typically 12V. The minimum operating voltage after turn-on, VCCoff, is typically 11V. The maximum supply voltage VCCmax is 18V. It is suggested to have the IC supplied with a regulated dc power supply for stable operation. At the same time, a small bypass filter capacitor is recommended to be put between VCC and GND pins, as close as possible. 7.2 Over Current Protection Current sense pin in ICE1HS01G/-1 is only for protection purpose. ICE1HS01G/-1 has two-level over current protection. In case of over-load condition, the 1st OCP level (0.8V) will be triggered and the switching frequency will be increased according to the duration and power of the over load. The 2nd OCP level (1.6V) is used to protect the converter if transformer winding is shorted. When Vcs reaches 1.6V, the IC will be latched immediately. If Vcs is higher than 0.8V, IC will boost up the switching frequency. If Vcs is lower than 0.75V, IC will resume to normal operation gradually. If Vcs is always higher than 0.8V for 1.5ms, the frequency will rise to its maximum level. And vice versa. To sum up, ICE1HS01G/-1 will increase the switching frequency to limit the resonant current in case of temporary over-load and will also decrease the switching frequency to its normal value after over-load condition is removed. 7.3 Over Load Protection In case of output over load or open control loop fault, the FB voltage will increase to its maximum level. If FB voltage is higher than VFBH and this condition last longer than a fixed blanking time of TOLP (20ms), the IC will start the extended blanking timer. The extended blanking timer is realized by charging and discharging the Application Note 9 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 filter capacitor CFB via the internal pull up resistor RFB and switch QFB. Accordingly the voltage across CFB varies between VFBL and VFBH. The time needed for CFB being charged from VFBL to VFBH can be calculated as: V VFBH tchg _ olp ln dd Vdd VFBL RFB CFB The time needed for CFB being discharged from VFBH to VFBL can be calculated as: V t dischg _ olp ln FBH VFBL RQFB C FB Thanks to an internal counter, the total extended blanking time can be calculated as: text _ blank 512 tchg _ olp tdischg _ olp where RQFB is switch QFB‘s on resitance, RQFB=900ohm, VFBH =4.5V, VFBL =0.5V. For example, if CFB is 680pF, t chg _ olp is about 30us, t dischg _ olp is about 1.4us, text _ blank is about 16ms. If the converter returns to normal operation during the extended blanking time, IC will reset the fault timer to zero and returns to normal operation. After IC enters into OLP, both switches will be stopped. However, the IC remains active and will try to start with soft start after an adjustable period. This period is realized by charging and discharging the capacitor CINS, connected to VINS pin, for NOLP_R times (NOLP_R=2048), accordingly the voltage across CINS varies between VINSH and VINSL. The charging and discharging time of CINS can be approximated as: t ch arg ing R VBUS eq I INST Req VINSH RINS1 Req C INS ln Req I INST Req VINSL VBUS RINS1 t dich arg ing R VBUS eq 2 VINSL RINS1 Req 2 C INS ln Req 2 VINSH VBUS RINS1 where Req is the equivalent resistance for parallelling of RINS1 and RINS2, Req RINS1 // RINS 2 Req2 is the equivalent resistance for parallelling of RINS1, RINS2 and RQ3 (900ohm typically). Req 2 RINS 1 // RINS 2 // RQ 3 Application Note 10 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 IINST is an internal constant current source IINST=750uA. VINSL and VINSH is the min. and max voltage at vins pin: VINSL=0.5V, VINSH=4.5V. For example, if assume RINS1=5Mohm, RINS2=22kohm, CINS=22nF, VBUS =380V, then tcharging=139us, tdischarging=44us. IC will repeat the charging and discharging process for NOLP_R times (NOLP_R=2048). After that, IC will turn off the switches for both charging and discharging. In addition, the current source for hysteresis will be turned on and another blanking time of TBL_VINS (TBL_VINS=20ms) will be added so that VINS pin fully recovers and represents the bus voltage information. IC will start with soft start after the additional blanking time in case VVINS is higher than the VVINSon. The total restart time can be calculated as: trestart 2048 tch arg ing tdisch arg ing 20ms 7.4 Mains Under Voltage Protection The working range of mains input voltage needs to be specified for LLC resonant converter. It is important for the controller to have input voltage sensing function and protection feature, which allows the IC to stop switching when the input voltage drops below the specified range and restart with soft start when the input voltage resumes to its normal level. The mains input voltage sensing circuit is shown in product datasheet [1]. Thanks to the internal current source Ihys (12uA) connected between VINS pin and Ground, an adjustable hysteresis between the on and off threshold of mains input voltage can be created as: Vhys RINS1 I hys The mains input voltage is divided by RINS1 and RINS2. If the on and off threshold for mains input voltage is Vmainon and Vmainoff, the resistors RINS1 and RINS2 can be selected as: RINS1 Vmainon Vmainoff I hys RINS 2 RINS 1 , VVINSon Vmainoff VVINSon where Ihys=12uA, VVINSon=1.25V. For example, if RINS1=5Mohm and RINS2=22kohm, the calculated Vmainon=345V, Vmainoff=285V. 7.5 Open Load Protection At very light load condition, eg. open load, the designed maximum frequency may not be high enough to regulate the output voltage, the output voltage may lose control and cause damages. In order to avoid this issue, the feedback signal VFB is continuously monitored. When VFB drops below VFB_off (typical 0.2V), the switching signal will be disabled after a fixed blanking time TFB (typical 200ns). VFB will then rise as Vout starts to decrease due to no pulse switching. Once VFB exceeds the threshold VFB_on (typical 0.3V), IC resumes to normal operation. Application Note 11 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 8 Circuit Diagram and Components List Schematics 4 8.1 BR1 00 KBU8G (8 A / 4 00V) + C100 22 0u/45 0V 2 D101 Q100 IPA50R 29 9CP 3 MB R2 560 CT TR 10 0 7 1 VCC HG LG GND CY1 00 QHG QHS QLG QLS 3 2 SGND 8 L1 02 1.2u /7 .5 A 1 R100 2M0 C103 C 104 L101 3. 3mH /4.6A 4 CX1 01 22 0nF /2 75Vac FMIN HG LG CS FB GND D104 D105 1N41 48 VINS + C111 CY1 022 n 2/Y1 R117 2k 2 C116 + ZD10 0 15 V C112 C 113 4 1 3 2 R112 13 k / 1% R114 30 k / 1% R111 68 0R R113 1k 0 R 115 3k 6 / 1% R 116 3k 6 / 1% C 114 33 nF R109 1k 1 R110 10 k 3 +1 5V GND N.C. C115 R108 5k 6 IC1 01 SF H6 17A-2 22 0nF 68 0pF /5 % 22 nF/5% C109 47 0uF/2 5V TR ANS-LLC-TWO 15 0 1u F/50V R 106 24 k+1 k + SGND 1N41 48 R104 1M0 FU SE 100 5A /250V + C 107 C 108 10 00u F/25V 10 00u F/25V R 107 75 2M0 N D100 MBR2 035 CT 11 R102 R103 R 105 22 k 12 V/5A D103 MB R2 035 CT 9 IC1 00 ICE1HS01 G / ICE1HS0 1G-1 S1 0k/27 5 VR1 00 10 C106 22 0pF / 630 V 10 uF/50 V10 0nF + C 110 47 0uF /3 5V C105 22 nF/63 0V CX1 00 10 0nF/2 75Vac (NC) 1 + 2n 2/Y1 RT10 0 S2 37/5 L + D102 MBR2 560 CT 2 IPA50R 29 9CP VCC 1.2u /7 .5 A 24 V/6A 6 Q101 + L1 00 C102 10 00u F/35V 3 CY1 01 2n 2/Y1 C 101 10 00u F/35V 1 IC1 02 2 TL431 Figure 6. – Schematic of 200W half bridge LLC resonant converter R201 10R QHG Rx1 1uF R200 8R5 1N4148 HG D202 MBR160 TR200 JP13 5 1 6 4 8 Dx1 11k QHS R206 10R QLG 7 R205 8R5 1N4148 LG Dx2 D204 MBR160 GND R207 11k QLS Figure 7a. – Schematic of the simplified driver module Application Note 12 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 Dx1 R201 10R Q200 R200 8R5 TR200 2 C200 D202 MBR160 Q202 1 1 6 4 8 1 3 3 3 N.C D207 1 Q204 ZD202 N.C 2 Q205 N.C C201 D204 MBR160 R207 11k 1N4148 Dx2 JP14 2 GND QLG D205 N.C D203 N.C LG R204 N.C QHS R206 10R 7 2 Rx1 ZD201 N.C N.C N.C R205 8R5 D206 5 N.C N.C Q203 ZD200 N.C 1 R203 N.C 2 Q201 N.C JP13 (N.C) 3 3 HG 11k 3 1uF D200 N.C 2 QHG R202 N.C D201 N.C N.C 1 VCC 1N4148 1 N.C ZD203 N.C N.C QLS Figure 7b. – Schematic of a reworked driver module in the PCB 8.2 PCB Layout 1 2 1 2 1 1 2 2 2 1 2 11 1 2 1 1 10 2 2 1 1 1 1 2 1 3 2 2 2 9 2 1 1 1 2 8 1 2 3 4 1 1 2 2 4 7 1 3 2 1 3 2 1 2 2 1 2 1 1 1 2 5 6 1 1 1 2 2 2 2 1 2 2 2 1 1 2 2 1 2 1 2 1 1 2 1 2 3 1 2 1 2 1 2 1 1 2 1 8 7 6 5 1 1 1 2 1 3 3 1 1 2 1 2 2 1 2 4 2 1 1 1 2 3 4 2 1 1 2 1 2 2 2 1 1 1 2 2 1 2 2 1 4 1 2 2 3 3 1 2 1 1 2 2 2 1 2 1 1 2 1 2 1 1 2 3 1 2 2 1 2 3 2 2 1 2 1 1 1 1 1 2 2 1 2 2 1 1 2 1 2 2 2 2 2 4 1 1 2 2 1 2 1 2 1 1 2 1 2 1 2 2 1 2 1 1 1 2 1 3 2 1 1 2 1 1 2 1 1 1 1 1 1 2 2 1 2 2 2 3 1 1 2 2 2 4 2 2 2 1 1 1 1 2 2 3 1 2 3 2 Figure 8a. Component side – View from component side Application Note 13 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 1 2 1 2 1 1 2 2 2 1 2 11 1 2 1 1 10 2 2 1 1 1 2 1 3 2 2 2 9 2 1 1 1 1 2 8 1 2 3 4 1 1 2 2 4 7 1 3 2 1 3 2 1 2 2 1 2 1 1 1 2 5 6 1 1 1 2 2 2 2 1 2 2 2 1 1 2 2 1 2 1 2 1 1 2 1 2 3 1 2 1 2 1 2 1 1 2 1 8 7 6 5 1 1 1 2 1 3 3 1 1 2 1 2 2 1 2 4 2 1 1 1 2 3 4 2 1 1 2 1 2 2 2 1 1 1 2 2 1 2 2 1 4 1 2 2 3 3 1 2 1 1 2 2 2 1 2 1 1 2 1 2 1 1 2 3 1 3 2 2 2 2 1 2 1 2 2 1 2 2 1 2 1 1 1 2 2 1 2 2 1 1 1 2 8 1 7 2 6 2 3 5 4 2 2 1 2 2 4 1 1 2 2 1 2 1 2 1 1 2 1 2 1 2 2 1 2 1 1 1 2 2 4 3 2 1 1 1 1 2 1 1 1 1 1 1 2 2 1 2 2 2 3 1 1 2 2 1 1 1 1 2 2 3 1 2 3 2 Figure 8b. Solder side copper – View from component side 8.3 Components List Designator Part Type Description BR100 KBU8G (8A / 400V) BRIDGE RECTIFIER C100 220u/450V Aluminum Electrolyte C101 1000uF/35V Aluminum Electrolyte C102 1000uF/35V Aluminum Electrolyte C103 10uF/50V Aluminum Electrolyte C104 100nF CERAMIC C105 22nF/630V CERAMIC C106 220pF / 630V CERAMIC C107 1000uF/25V Aluminum Electrolyte C108 1000uF/25V Aluminum Electrolyte C109 470uF/25V Aluminum Electrolyte C110 470uF/35V Aluminum Electrolyte C111 220nF CERAMIC C112 680pF/5% CERAMIC C113 22nF/5% CERAMIC C114 33nF CERAMIC C115 N.C. CERAMIC C116 1uF/50V Aluminum Electrolyte Application Note 14 Supplier / Part No. EPCOS / B43304C5227M000 EPCOS / B41821A6106M000 EPCOS / B32621A6223J000 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 CX100 100nF/275Vac X-cap. CX101 220nF/275Vac X-cap. CY100 2n2/Y1 Y-cap. CY101 2n2/Y1 Y-cap. CY102 2n2/Y1 Y-cap. D100 MBR2035CT SCHOTTKY DIODE D101 MBR2560CT SCHOTTKY DIODE D102 MBR2560CT SCHOTTKY DIODE D103 MBR2035CT SCHOTTKY DIODE D104 1N4148 DIODE D105 1N4148 DIODE D202 MBR160 DIODE D204 MBR160 DIODE Dx1 (reworked) 1N4148 DIODE Dx2 (reworked) 1N4148 DIODE FUSE100 IC101 5A/250V ICE1HS01G / ICE1HS01G-1 SFH617A-2 FUSE Resonant-Mode Controller OPTO COUPLER IC102 TL431 2.5V voltage reference JP3 1uF/50V CERAMIC L100 1.2u/7.5A L101 3.3mH/4.6A EPCOS / B82734R2462B30 L102 1.2u/7.5A D-CHOKE COMMON MODE CHOKE D-CHOKE Q100 IPA50R299CP POWER MOSFET Infineon Q101 IPA50R299CP POWER MOSFET Infineon R100 2M0 RESISTOR R102 150 RESISTOR R103 2M0 RESISTOR R104 1M0 RESISTOR R105 22k RESISTOR R106 24k+1k RESISTOR R107 75 RESISTOR R108 5k6 RESISTOR R109 1k1 RESISTOR R110 10k RESISTOR R111 680R RESISTOR R112 13k / 1% RESISTOR R113 1k0 RESISTOR R114 30k / 1% RESISTOR R115 3k6 / 1% RESISTOR IC100 Application Note 15 EPCOS / B32922C3224K000 EPCOS / B81123C1222M000 EPCOS / B81123C1222M000 EPCOS / B81123C1222M000 Infineon 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 R116 3k6 / 1% RESISTOR R117 2k2 RESISTOR R200 8R5 RESISTOR R201 10R RESISTOR R205 8R5 RESISTOR R206 10R RESISTOR R207 11k RESISTOR Rx1 (reworked) 11k RESISTOR RT100 S237/5 Thermister TR100 TRANS-LLC-TWO EC32 PC47 core TR200 Pulse Transformer E16/8/5 N87 core VR100 S10k/275 VDR Epcos / B57237S509M000 Epcos Epcos / B72210S271K101 Table 2. Bill of Materials 9 Electrical Test Results 9.1 Efficiency Measurements Table 3 shows the output voltage measurements at the nominal input bulk voltage 380Vdc, with different load conditions. The bulk voltage 380Vdc is directly supplied from Chroma programmable DC power supply. Hense, there is no current flowing through the bridge rectifier, and the measured efficiency is actually the LLC stage’s efficiency. 24Vout [V] 24.190 24.160 24.130 24.100 24.060 24.060 24Vout current [A] 5.989 4.988 3.984 2.996 1.993 0.990 12Vout [V] 11.830 11.840 11.860 11.870 11.880 11.880 12Vout current [A] 4.978 3.980 2.982 1.986 0.989 0.489 Pinput_main power [W] 214.300 175.900 137.900 100.700 63.400 32.600 Pinput_IC and Driver [W] 0.608 0.608 0.608 0.608 0.608 0.608 Poutput [W] 203.761 167.625 131.505 95.785 59.707 29.632 Efficiency [%] 94.813 94.967 94.944 94.548 93.280 89.232 Table 3. Efficiency measurements @ Vbulk=380Vdc Application Note 16 03 July 2013 Efficiency (%) 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 Figure 9. LLC stage efficiency The power losses due to IC and driver circuit are both included. In addition, the efficiency values were measured after 30 minutes of warm-up at full load. 9.2 Zero Voltage Switching From above test result, ZVS can be obtained over a very wide range of load; both Q100 and Q101 are in zero voltage switching during turn on while the current is resonating positive and negative alternatively. VDS_Q101 VDS_Q101 Ip_TR100 Ip_TR100 VLG VLG VHG VHG ZVS @ 380Vdc bulk voltage and 100% full load ZVS @ 380Vdc bulk voltage and 10% full load Figure 10. Zero Voltage switching Application Note 17 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 9.3 Soft Start VFB VFB Vout Vout 24V Ip Ip Vgate Vgate fswi fswi Soft start @ 380Vdc bulk voltage and full load 24V Soft start @ 380Vdc bulk voltage and no load Figure 11. Soft start at full load and no load During startup at full load or no load, the primary resonant current is strictly limited, and the 24V output voltage smoothly rises to its regulated value. The overshoot is less than 5%, the start up time is less than 30ms. 9.4 Mains Under Voltage Protection Vbus Vbus VVINS VVINS Vgate Vgate IC starts operation when Vbus resumes to nomal value IC stop switching when Vbus drops to designed value Figure 12. Mains under voltage protection When Vbus drops lower than 282Vdc, IC stops switching; When Vbus rises up to 336V, IC starts normal operation after a 500us blanking time. These measured results are closely equal to the calculated results mentioned at section 7.4. Application Note 18 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 9.5 Output Short Circuit Protection Total : 388ms Vo_24V VFB VVINS VLG Internally fixed blanking time 20ms measured : 15.5ms Adjustable blanking time measured : 18ms Adjustable restart time measured : 339ms Internally fixed restart time 20ms measured : 15.5ms Figure 13. Output short circuit protection When the output load is short circuit, VFB Jumps to a higher value, when this condition lasts longer than the internal fixed blanking time 20ms, the extended adjustable blanking time will be initiated. After this two blanking time, IC will enter restart mode if this short circuit condition still exist, and it stops switching. After an adjustable restart time and an internal fixed restart time 20ms, IC resumes to normal operation with soft start. During soft start, the over load protection is disabled. When softstart process is completed and the output is still under short circuit condition, IC will enter autorestart mode again. When the output short circuit condition is removed, IC will resume to normal operation and the 24V output voltage is resumed again. The overall measured blanking tiem before entering auto-restart protection is 388ms. Application Note 19 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 9.6 9.6.1 Over Load Protection Adjustable blanking time Vo_24V Vo_24V VFB VFB VVINS VVINS VLG VLG VFB VFB CFB charging time CFB discharging time Figure 14. Adjustable extended blanking time in case of over load protection Blanking time in case of over load protection can be adjusted as discussed before. The charging time tchg_olp and discharging time tdischg_olp of CFB is 32.5us and 2.8us respectively. The measured overall adjustable blanking time is 18ms. 9.6.2 Adjustable restart time Vo_24V VFB Vo_24V VFB V VVINS VVINS VLG VLG VVINS VVINS CVINS charging time CVINS discharging time Figure 15. Adjustable restart time in case of over load protection Restart time in case of over load protection can also be adjusted as discussed before. The charging time tcharge and discharging time tdischarge of Cvins is 120us and 45us respectively. The measured overall adjustable restart time is 339ms. Application Note 20 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 9.7 Burst Mode Operation at No Load Vout 24V ac VFB Vgate Figure 16. Burst mode operation Burst mode operation is implemented in ICE1HS01G/-1 to avoid possible over output voltage issue in case of light load or no load operation. When VFB drops below VFB_off (measured value 0.185V), the switching signal will be disabled. VFB will then rise as Vout starts to decrease due to no switching signal. Once VFB exceeds the threshold VFB_on (measured value 0.296V), IC resumes to normal operation. 9.8 Dynamic Load Response Vout_24V Vout_24V Vout_12V Vout_12V Iout_12V Iout_24V 24V @ 6A, 12V @ 0.5A-5A 24V @ 0.5A-6A, 12V @ 5A Figure 17. Dynamic load response Figure 17 shows the dynamic behavior of this demoboard during a load variation (12V) from around 10% to 100% full load on one output, with the other output (24V) at its full load. The output voltage ripple of 24V and 12V are both less than 5%. Application Note 21 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 10 10.1 Transformer Constructure Mains Transformer Bobbin: Split type EC32, Horizontal version from TDK Core: PC47 EC32 from TDK Primary inductance: 636μH±5%, Gapped between Pin 1 and Pin 3 Leakage inductance: 120μH±5%, measured between Pin 1 and Pin 3 by shorting (Pin 6 & 8 and Pin 9 &11) or (Pin 6 & 7 and Pin 9 & 10) Measured at frequency of 40kHz Figure 18. LLC resonant transformer electrical diagram Figure 19. LLC resonant transformer winding position Figure 20. LLC resonant transformer complete – top view Application Note 22 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 Pins 1~3 8~6 6~7 11~9 9~10 winding primary Secondary 1 Secondary 2 Secondary 3 Secondary 4 turns 34 4 4 2 2 wire 13*0.20 16*0.20 16*0.20 19*0.20 19*0.20 Table 4. LLC resonant transformer winding characteristics 10.2 Pulse Transformer Bobbin: E16/8/5, Vertical version from EPCOS Core: E16/8/5 N87 from EPCOS Pin 8 Vertical bobbin Pin 1 Pin 1 Pin 2 Pin 3 Pin 4 Pin 7 Pin 5 Pin 4 Pin 8 Pin 7 Pin 6 Pin 5 Pin 6 Figure 21. Pulse Transformer electrical diagram Figure 22. Pulse transformer complete – top view Figure 23. Pulse transformer winding position Application Note 23 03 July 2013 200W SMPS using LLC Resonant Controller ICE1HS01G/-1 11 References [1] ICE1HS01G datasheet, Infineon Technologies AG, 2009 [2] ICE1HS01G-1 datasheet, Infineon Technologies AG, 2012 [3] RW ERICKSON, D MAKSIMOVIC: ‘Fundamentals of power electronics’ (Kluwer Academic Publishers, 2001), pp. 705–755 [4] B Yang: ‘Topology investigation for front end DC/DC power conversion for distributed power system’, PhD thesis, Virginia Polytechnic Institute and State University, 2003 [5] Mingping Mao, Dimitar Tchobanov, Dong Li, Martin Maerz, Tobias Gerber, Gerald Deboy, Leo Lorenz.: ‘Analysis and design of a 1MHz LLC Resonant Converter with Coreless transformer driver’. PCIM Conference, Shanghai. 2007 [6] M Mao, D Tchobanov, D Li, M Maerz.: ‘Design optimization of a 1MHz half bridge CLL resonant converter’. IET Power Electronics, 2008, Vol.1, pp. 100-108. Application Note 24 03 July 2013