Version 2.0, August 2003 Application Note AN-EVALSF2-ICE2A0565Z-2 CoolSET 10W 5.0V Evaluation Board with ICE2A0565Z Author: Rainer Kling Published by Infineon Technologies AG http://www.infineon.com/CoolSET/ Power Management & Supply N e v e r s t o p t h i n k i n g 10W 5V Demoboard using ICE2A0565Z on Board Table of Contents TABLE OF CONTENTS.......................................................................................................................... 1 INTRODUCTION ..................................................................................................................................... 2 APPLICATION.......................................................................................................................................... 2 COOLSET........................................................................................................................................... 2 LIST OF FEATURES .............................................................................................................................. 3 POWER SUPPLY SPECIFICATION....................................................................................................... 3 SCHEMATIC ........................................................................................................................................... 4 PCB COMPONENT LEGEND................................................................................................................. 5 PCB LAYOUT ......................................................................................................................................... 5 DESCRIPTION ........................................................................................................................................ 6 Introduction....................................................................................................................................... 6 Line Input.......................................................................................................................................... 6 Startup .............................................................................................................................................. 6 Operation Mode................................................................................................................................ 6 Softstart ............................................................................................................................................ 6 Snubber Network.............................................................................................................................. 6 Limitation of primary current............................................................................................................. 6 Output Voltage ................................................................................................................................. 6 Regulation ........................................................................................................................................ 6 BILL OF MATERIAL ............................................................................................................................... 7 TRANSFORMER CONSTRUCTION DOCUMENTATION ..................................................................... 8 PERFORMANCE DATA ......................................................................................................................... 9 EFFICIENCY............................................................................................................................................ 9 NO-LOAD INPUT POWER (STANDBY)...................................................................................................... 10 REGULATION AND POWER LIMITING ....................................................................................................... 10 W AVEFORMS AND SCOPE PLOTS .......................................................................................................... 12 Startup @ Low and High AC Line Input Voltage and Nominal Load ............................................. 12 Drain Source Voltage and Current During Normal Operation........................................................ 12 Load Transient Response (Loadjump from 10% Load until 100% Load) ...................................... 13 AC Output Ripple during Nominal Load and Normal Operation .................................................... 13 INPUT CAPACITOR IMPROVEMENT – SLOPE COMPENSATION ................................................................... 14 Input Capacitor Improvement......................................................................................................... 14 Slope Compensation ...................................................................................................................... 14 REFERENCES ...................................................................................................................................... 16 www.Infineon.com/CoolSET Page 1 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Introduction Application This document is an engineering report that describes an universal input power supply designed in a typical off line flyback converter topology that utilizes the ICE2A0565Z CoolSET. The application operates in discontinuous current mode using the frequency reduction during standby condition. The board has one output voltage with secondary regulation. This board was designed to demonstrate the basic performance, the features and the power capability of the smallest CoolSET device ICE2A0565Z of the second generation of CoolSET in a DIP7 package with extended creepage distance for higher electrical strength. CoolSET CoolSET is a current mode PWM control IC and the power MOSFET CoolMOS within one package designed for low cost switch mode power supplies (SMPS). CoolSET combines the superior technology of CoolMOS and the optimized technology of the control IC with enhanced protection features and improved standby power concept. The integrated propagation delay compensation (patented by Infineon Technologies) prevents a current overshoot, the result is a reduced electrical stress on the MOSFET, the transformer and the output diode. The 650V / 800V high avalanche rugged CoolMOS eliminates or reduces the need for a heat sink and permits a SMPS design with a simply RCD snubber and a low cost standard transformer design. The lowest area specific Rdson leads to a high efficiency and an operation at high ambient temperature. CoolSET permits always a safety operation during any error cases due to the integrated protection features. Figure 1– EVALSF2-ICE2A0565Z This document contains the list of features, the power supply specification, schematic, bill of material and the transformer construction documentation. Typical operating characteristics are presented at the rear of the report and consist of performance curves and scope waveforms. Note: Design calculations for the components and the transformer were performed in accordance with the application note “AN–SMPS–ICE2AXXX for OFF – Line Switch Mode Power Supplies” and FlyCal, a EXCEL based design software according to the application note AN-SMPS-ICE2AXXX. The application note and FlyCal are available on the Internet: www.Infineon.com/CoolSET www.Infineon.com/CoolSET Page 2 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board List of Features Feature CoolSET Device ICE2A0565Z External Sense Adjustable Soft start Modulated Gate drive Over Load Protection with auto restart Over Current Protection with auto restart Over Temperature Shut Down with auto restart Open Loop Protection with auto restart Under Voltage Lock Out with auto restart 1 Drain Source Voltage 650V Frequency Reduction Internal Leading Edge Blanking 100 kHz working frequency DIP7 Package with extended Creepage Distance Standby Power according to European Commission Table 1 – List of Features Power Supply Specification Description Input Voltage Line Regulation (85...270V) Input Frequency 2 No Load Input Power (90VAC) 2 No Load Input Power (230VAC) Output Voltage AC Output Voltage Ripple Output Current Output Power Nominal Peak Power Total Regulation Efficiency (90VAC) Efficiency (270VAC) Symbol Min Input Section VACIN 85 f 47 Typ Max Units 115/230 <1 50/60 0.18 0.41 270 VAC % Hz W W 5.0 <50 2.0 10 16 ±2 78 79 5.1 Output Section VOUT 4.90 VRipple IOUT 1.90 POUT POUTmax η η 64 2.1 VDC mVP-P ADC W W % % % Environmental Conducted EMI Ambient Temperature TA 0 Thermal Consideration Transformer CoolSET Output Diode Output Capacitors 50 40 60 70 20 75 EN55022B °C °C °C °C °C Table 2 – Power Supply Specification 1 2 VDSBR at Tj = 110°C Frequency Reduction Mode (fStandby = 21 kHz) and POUT = 0W www.Infineon.com/CoolSET Page 3 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Schematic Figure 2 10W 5.0V ICE2A0565Z Power Supply Schematic www.Infineon.com/CoolSET Page 4 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board PCB Component Legend W1 W2 Figure 3 Component Legend PCB Layout Figure 4 Board Layout - Component Side www.Infineon.com/CoolSET Page 5 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Description Introduction The EVALSF2-ICE2A0565Z demoboard is a low cost off line flyback switch mode power supply (SMPS) using the ICE2A0565Z system IC from the CoolSET-F2 family. The circuit, shown in Figure 2, details a 5.0V, 10W power supply that operates from an AC line input voltage range of 85 to 265VAC, suitable for applications requiring either an open frame supply or an enclosed adapter. Line Input The AC line input side comprises of an input fuse F1 as line input over current protection as well as choke L5 and the X2 capacitor C8 as radio interference suppressors. After the bridge rectifier BR1 and input capacitor C3, a voltage from 120 to 380 VDC is present. Due to the extended duty cycle DMAX 3 of the ICE-F2-family there is the possibility to replace the 47µF input capacitor with a 22µF (2.2µF/W) . Startup From this voltage, the chip starting the current supply is derived using resistors R6 and R7. Because of the very low start up current of typically 27µA, a high-value resistor can be used. Operation Mode During operation, the VCC pin is supplied via a separate transformer winding with associated rectification D2 and buffering C4, C13. Resistor R8 is used for current limiting during the charging of C4. In order not to exceed the maximum voltage at VCC pin an external zener diode D4 limits this voltage. During light or no load condition, the switching frequency is automatically and continuously 4 reduced down to 21kHz in order to reduce the switching losses. Softstart The Soft-Start function is realized by an internal resistor and the adjustable external capacitor C14. Snubber Network The network R10, C12 and D3 clamp the DRAIN voltage spike caused by transformer leakage 5 inductance to a safe value below the drain source break down voltage VDSBR = 650V maximum. Limitation of primary current The CoolMOS drain source current is sensed via external shunt resistors R17. An accurate value of the shunt improves the peak power limitation shown in the curve peak power limitation in the rear of this report. Output Voltage Power is coupled out on the secondary side via a fast-acting diode D1 with low forward voltage. Capacitor C5 performs energy buffering, a following LC - filter C9 and inductor L3 considerably reduces the output voltage ripple. Storage output capacitor C5 is designed to exhibit a very low ESR in order to minimize the output voltage ripple caused by the triangular 100kHz current characteristic. The output voltage is set with resistors R1 and R2. Regulation The output voltage is controlled using a type TL431 reference diode (IC2). This device incorporates the voltage reference as well as the error amplifier and a driver stage. Compensation network C1, C2, R1, R5 constitutes the external circuitry of the error amplifier of IC2. This circuitry allows the feedback to be precisely matched to dynamically varying load conditions, thereby providing stable control. The maximum current through the optocoupler diode and the voltage reference is set by using resistors R3, R4. Optocoupler IC1 is used for floating transmission of the control signal to the “Feedback” input via resistor R9 and capacitor C6 of the ICE2A0565Z control device. The optocoupler used meets DIN VDE 884 requirements for a wider creepage distance. 3 4 5 Slope Compensation is needed due to Current Mode Control and Dnom > 50% see description in the rear of the report Without audible noise VDSBR = 650V @ Tj = 110°C www.Infineon.com/CoolSET Page 6 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Bill of Material ICE2A0565Z Evaluation Board 5.0V/ 10W Pos. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 Part Type Number BR1 B500 C1500 1 C1 [nF] 470 1 C2 [nF] 10 1 C3 [µF] 47 1 C4 [µF] 22 1 C5 [µF] 1000 1 C6 [nF] 2.2 1 C7 [nF] 2.2 1 C8 [µF] 0.1 1 C9 [µF] 470 1 C12 [nF] 1.0 1 C13 [nF] 100 1 C14 [nF] 100 1 D1 MUR540 1 D2 1N4148 1 D3 1N4937 1 D4 ZPD18 1 F1 Microfuse 3.15A 1 IC1 SFH617A-3X016 1 IC2 TL431CLP 1 IC3 ICE2A0565Z 1 L3 [µH] 1.0 1 L5 [µH] 2*27mH / 0.9A 1 R1 [kOhm] 3.3 1 R2 [kOhm] 3.3 1 R3 [kOhm] 0,082 1 R4 [kOhm] 1.2 1 R5 [kOhm] 2,7 1 R6 [kOhm] 360 1 R7 [kOhm] 360 1 R8 [Ohm] 4.3 1 R9 [Ohm] 22 1 R10 [kOhm] 100 1 R17 [Ohm] 1.1 1 TR1 E20/10/6 1 W1 Wire 1 W2 Wire 1 X1 Connector 2pol. 1 X2 Connector 2pol. 1 www.Infineon.com/CoolSET Values Page 7 of 16 Others 50V X7R 50V X7R 400V B43504-A9476-M 63V 25V Low ESR – B41886 50V X7R 250V Y1 Cap 275V X2 Cap 25V Low ESR – B41886 400V MKT 50V X7R 50V X7R 400V 18V 3.15A 6A 262LYF-0074M 0.9A 1% 0.50 Mm EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Transformer Construction Documentation Core Material: E20/10/6; N87 Frequency: 100 kHz gap: 0.5mm Al = 103nH Lp = 503µH Coil former: horizontal version 35 turns 2 x 0,2 mm Ø Prim. 4 turns 3 x 0,5 mm Ø Sec. 10 turns 3 x 0,2 mm Ø Aux. 35 turns 2 x 0,2 mm Ø Prim Pin 1 Pin Pi 2n8 Pin 10 Pin 5 Pin 4 Pin 2 Pin 3 center leg meens one layer Makrofol Top view: Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 www.Infineon.com/CoolSET Pin 10 Pin 9 Pin 8 Pin 7 Pin 6 Page 8 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Performance Data Efficiency Efficiency versus AC Line Input Voltage 100 Efficiency [%] 90 80 70 60 50 50 100 150 200 250 300 AC Line Input Voltage [V] Efficiency @ 10W Output Power Figure 5 Efficiency vs. AC Line Input Voltage Efficiency versus Output power 100 90 80 Efficiency [%] 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 Output Power[W] Vacin = 85V Vacin = 270V Figure 6 Efficiency vs. Output Power @ Low and High Line 50Hz www.Infineon.com/CoolSET Page 9 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board No-Load Input Power (Standby) Standby versus AC Line Input Voltage 0,7 TAMB = 25 °C 0,6 Input Power [W] 0,5 0,4 0,3 0,2 0,1 0 50 100 150 200 250 300 AC Line Input Voltage [V] Standby Power Figure 7 No Load Input Power (Standby) vs. AC Line Input Voltage @ Pout = 0W Regulation and Power Limiting Line Regulation: Vout versus AC Line Input Voltage @ nominal Load 6 Output Voltage [V] 5,75 5,5 5,25 5 4,75 4,5 4,25 4 50 100 150 200 250 300 AC Line Input Voltage [V] Output Voltage Figure 8 Line Regulation vs. AC Line Input Voltage www.Infineon.com/CoolSET Page 10 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Load Regulation: Vout versus Load @ Vacin = 230V 6 5,75 Output Voltage [V] 5,5 5,25 5 4,75 4,5 4,25 4 0 1 2 3 4 5 6 7 8 9 10 11 12 Output Power [W] Output Voltage Figure 9 Load Regulation Max. Overload Output Power (Peak Power) versus AC Line Input Voltage Max. Overload Output Power [W] 18 17,5 17 16,5 16 15,5 15 14,5 14 50 100 150 200 250 300 AC Line Input Voltage [V] Peak Power Figure 10 Overload Output Power (Over Current Shut Off Threshold) vs. Line Input Voltage www.Infineon.com/CoolSET Page 11 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Waveforms and Scope Plots All waveforms and scope plots where recorded with a Tectronix TDS 745D Startup @ Low and High AC Line Input Voltage and Nominal Load Channel 1: Chip Supply Voltage (VCC) Channel 2: Feedback Voltage (VFB) Channel 3: Soft Start Voltage (VSS) Channel 4: Output Voltage (VOUT) Channel 1: Chip Supply Voltage (VCC) Channel 2: Feedback Voltage (VFB) Channel 3: Soft Start Voltage (VSS) Channel 4: Output Voltage (VOUT) Figure 11 Startup @ Vacin = 85V and nom. Load Figure 12 Startup @ Vacin = 270V and nom.Load Drain Source Voltage and Current During Normal Operation Channel 1: Drain Current (ID) Channel 4: Drain Source Voltage (VDS) Dmax = 41% / VRsense = 800mV Channel 1: Drain Current (ID) Channel 4: Drain Source Voltage (VDS) Dmax = 10% / VRsense = 800mV Figure 13 Operation @ Vacin = 85V and nom. Load Figure 14 Operation @ Vacin = 270V and nom.Load www.Infineon.com/CoolSET Page 12 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Load Transient Response (Loadjump from 10% Load until 100% Load) Channel 2: Feedback Voltage (VFB) Channel 2: Feedback Voltage (VFB) Figure 15 Loadjump @ Vacin = 85V and nom. Load Figure 16 Loadjump @ Vacin = 270V and nom.Load AC Output Ripple during Nominal Load and Normal Operation AC Output Voltage Ripple High Frequency Probe Coupling Channel 1: AC Output Ripple (VACOUT) VACOUTmax = ± 10mV Details of AC output voltage ripple measurements. The probe GND should be as short as possible to minimize the high frequency probe coupling. Figure 17 AC Output Voltage Ripple at nom. Load Figure 18 AC Ripple Measurement Technique www.Infineon.com/CoolSET Page 13 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Input Capacitor Improvement – Slope Compensation Input Capacitor Improvement In case you are using a smaller input capacitor (22µF instead of 47µF), the maximum duty cycle increases. To make sure, that the board is not working in the continuous conduction mode, a different transformer is necessary; otherwise, you have to assemble slope compensation on board. Slope Compensation Any kind of current mode controller needs to have slope compensation in case the application is designed for the continuous conduction mode (CCM) and the maximum duty cycle exceeds the 50% threshold. Below you see the impact on the system in case of an input capacitor reduction; with the 47µF bulk works the board in the discontinuous conduction mode (DCM) and a Dmax < 50%; with the smaller 22µF bulk, the board is running in the continuous conduction mode (CCM) and Dmax > 50%. Channel 1: Drain Current (ID) Channel 4: Drain Source Voltage (VDS) CIN = 47µF / Dmax = 43% / Pout = 12W / VACIN = 85V Channel 1: Drain Current (ID) Channel 4: Drain Source Voltage (VDS) CIN = 22µF / Dmax = 72% / Pout = 12W / VACIN = 85V Figure 19 DCM – Operation with Dmax < 50% Figure 20 CCM – Operation with Dmax > 50% To prevents an instability of the regulation loop, in case of CCM and Dmax > 50%, assemble just three more components (2 ceramic capacitors C17 / C18 and one resistor R19) as shown in the circuit diagram below. Figure 21 Circuit Diagram Switch Mode Power Supply with Slope Compensation More information regarding how to calculate the additional components, see in the application note AN_SMPS_ICE2xXXX – available on the internet: www.infineon.com/CoolSET CoolSET F2. www.Infineon.com/CoolSET Page 14 of 16 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board Note: The built-in transformer does not comply with EN60950 safety requirements in respect of electrical isolation. Change service Issue status 1.0 1.2 2.0 Changes First issue Replace Device ICE2A165 with ICE2A0565Z Update: ! Board ! BOM ! Transformer construction Additional: ! Performance Data ! Slope Compensation www.Infineon.com/CoolSET Page 15 of 16 Date 02.05.2002 Aug. 2002 Aug. 2003 EVALSF2-ICE2A0565Z V2.00 10W 5V Demoboard using ICE2A0565Z on Board References [1] ICE2AXXX for OFF-Line Switch Mode Power Supplies Application Note, Infineon Technologies [2] CoolSET -II Off-line SMPS Current Mode Controller with High Voltage CoolMOS on Board Datasheet, Infineon Technologies Revision History Application Note AN-EVALSF2-ICE2A0565Z-01 Actual Release: 2.0 Date: 2003-08-09 Previous Release: V1.0 Page of actual Rel. -- Page of Subjects changed since last release prev. Rel. -- See change service www.Infineon.com/CoolSET Page 16 of 16 EVALSF2-ICE2A0565Z V2.00