AN-PS0042-ICE3AR2280JZ-5V20W-V11_11Aug2010

N e v e r s t o p t h i n k i n g . Power Management & Supp ly AN-EVAL3AR2280JZ 2 0 W 5 V S M P S E v a l u a t i o n B o a r d w i t h C o o l S E T ® F 3 R 8 0 I C E 3 A R 2 2 8 0 J Z App l i ca t i on No te , V1 .1 , Aug 2010 Edition 2010-08-11 Published by Infineon Technologies Asia Pacific, 8 Kallang Sector, 349282 Singapore © Infineon Technologies AP 2010. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as a guarantee of characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Information For further information on technology, delivery terms and conditions and prices please contact your 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 your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems 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 20W 5V Demoboard using ICE3AR2280JZ on board Revision History: 2010-08 V1.1 Previous Version: 1.0 Page Subjects (major changes since last revision) 1, 6, 8 Change demo board name to EVAL3AR2280JZ 20W 5V SMPS Evaluation Board with CoolSET®F3R80 ICE3AR2280JZ: License to Infineon Technologies Asia Pacific Pte Ltd AN-PS0042 Kyaw Zin Min Kok Siu Kam Eric 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: ap-lab.admin@infineon.com 20W 5V Demoboard using ICE3AR2280JZ Table of Contents Page Application Note 4 2010-08-11 1 Abstract..........................................................................................................................................6 2 Evaluation board ...........................................................................................................................6 3 List of features...............................................................................................................................7 4 Technical specifications...............................................................................................................7 5 Circuit description ........................................................................................................................8 5.1 Introduction......................................................................................................................................8 5.2 Line input.........................................................................................................................................8 5.3 Start up............................................................................................................................................8 5.4 Operation mode ..............................................................................................................................8 5.5 Soft start ..........................................................................................................................................8 5.6 RCD clamper circuit ........................................................................................................................8 5.7 Peak current control of primary current...........................................................................................8 5.8 Output stage....................................................................................................................................9 5.9 Feedback and burst entry/exit control.............................................................................................9 5.10 Blanking window for load jump........................................................................................................9 5.11 Brownout mode .............................................................................................................................10 5.12 Active burst mode .........................................................................................................................11 5.13 Jitter mode, soft gate drive and the 50Ω gate turn on resistor .....................................................11 5.14 Protection modes ..........................................................................................................................11 6 Circuit diagram............................................................................................................................13 7 PCB layout ...................................................................................................................................15 7.1 Top side.........................................................................................................................................15 7.2 Bottom side ...................................................................................................................................15 8 Component list ............................................................................................................................16 9 Transformer construction ..........................................................................................................17 10 Test results ..................................................................................................................................18 10.1 Efficiency.......................................................................................................................................18 10.2 Input standby power......................................................................................................................19 10.3 Line regulation...............................................................................................................................20 10.4 Load regulation .............................................................................................................................21 10.5 Max. output power.........................................................................................................................21 10.6 ESD test ........................................................................................................................................22 10.7 Lightning surge test.......................................................................................................................22 10.8 Conducted EMI..............................................................................................................................22 11 Waveforms and scope plots ......................................................................................................25 11.1 Start up at low and high AC line input voltage and max. load ......................................................25 11.2 Soft start at low and high AC line input voltage and max. load.....................................................25 11.3 Frequency jittering.........................................................................................................................26 11.4 Drain to source voltage and Current at max. load ........................................................................26 11.5 Load transient response (Dynamic load from 10% to 100%) .......................................................27 11.6 Output ripple voltage at max. load ................................................................................................27 11.7 Output ripple voltage during burst mode at 1 W load ...................................................................28 11.8 Entering active burst mode ...........................................................................................................28 11.9 Vcc over voltage protection (Odd skip auto restart mode)............................................................29 11.10 Over load protection (Odd skip auto restart mode).......................................................................29 11.11 Open loop protection (Odd skip auto restart mode)......................................................................30 11.12 VCC under voltage/Short optocoupler protection (Non switch auto restart mode).........................30 11.13 External protection enable (Non switch auto restart mode)..........................................................31 11.14 Brownout mode .............................................................................................................................31 12 Appendix ......................................................................................................................................32 12.1 Slope compensation for CCM operation .......................................................................................32 20W 5V Demoboard using ICE3AR2280JZ Table of Contents Page Application Note 5 2010-08-11 13 References ...................................................................................................................................32 20W 5V Demoboard using ICE3AR2280JZ Application Note 6 2010-08-11 1 Abstract This document is an engineering report of an universal input 20W 5V off-line flyback converter power supply utilizing IFX F3R80 CoolSET® ICE3AR2280JZ. The application demo board is operated in Discontinuous Conduction Mode (DCM) and is running at 100 kHz switching frequency. It has a single output voltage with secondary side control regulation. It is especially suitable for small power supply such as DVD player, set-top box, game console, charger and auxiliary power of high power system, etc. The ICE3AR2280JZ is the latest version of the CoolSET®. Besides having the basic features of the F3R CoolSET® such as Active Burst Mode, propagation delay compensation, soft gate drive, auto restart protection for major faults (Vcc over voltage, Vcc under voltage, over temperature, over-load, open loop and short opto-coupler), it also has the BiCMOS technology design, selectable entry and exit burst mode level, adjustable brownout feature, built-in soft start time, built-in and extendable blanking time, frequency jitter feature and external auto-restart enable, etc. The particular features need to be stressed are the best-in-class low standby power and the good EMI performance. 2 Evaluation board Figure 1 – EVAL3AR2280JZ This document contains the list of features, the power supply specification, schematic, bill of material and the transformer construction documentation. Typical operating characteristics such as performance curve and scope waveforms are showed at the rear of the report. 20W 5V Demoboard using ICE3AR2280JZ Application Note 7 2010-08-11 3 List of features 800V avalanche rugged CoolMOS® with Startup Cell Active Burst Mode for lowest Standby Power Selectable entry and exit burst mode level 100kHz internally fixed switching frequency with jittering feature Auto Restart Protection for Over load, Open Loop, VCC Under voltage & Over voltage and Over temperature External auto-restart enable pin Over temperature protection with 50°C hysteresis Built-in 10ms Soft Start Built-in 20ms and extendable blanking time for short duration peak power Propagation delay compensation for both maximum load and burst mode Adjustable brownout feature Overall tolerance of Current Limiting < ±5% BiCMOS technology for low power consumption and wide VCC voltage range Soft gate drive with 50Ω turn on resistor 4 Technical specifications Input voltage 85Vac~282Vac Brownout detect/reset voltage 75/85Vac Input frequency 50/60Hz Input Standby Power < 100mW @ no load Output voltage 5V +/- 1% Output current 4A Output power 20W Acitve mode average efficiency >75% Output ripple voltage < 50mVp-p 20W 5V Demoboard using ICE3AR2280JZ Application Note 8 2010-08-11 5 Circuit description 5.1 Introduction The EVAL3AR2280JZ demo board is a low cost off-line flyback switch mode power supply (SMPS) using the ICE3AR2280JZ integrated power IC from the CoolSET®-F3R80 family. The circuit, shown in Figure 3, details a 5V, 20W power supply that operates from an AC line input voltage range of 85Vac to 282Vac and brownout detect/reset voltage is 75/85Vac, suitable for applications in enclosed adapter or open frame auxiliary power supply for different system such as PC, server, DVD, LED TV, Set-top box, etc. 5.2 Line input The AC line input side comprises the input fuse F1 as over-current protection. The choke L11, X1-capacitor C11, and Y1-capacitor C15 act as EMI suppressors. Optional spark gap device SG1, SG2 and varistor VAR can absorb high voltage stress during lightning surge test. After the bridge rectifier BR1 and the input bulk capacitor C13, a voltage of 120 to 400 VDC is present which depends on input voltage. 5.3 Start up Since there is a built-in startup cell in the ICE3AR2280JZ, there is no need for external start up resistors. The startup cell is connecting the drain pin of the IC. Once the voltage is built up at the Drain pin of the ICE3AR2280JZ, the startup cell will charge up the Vcc capacitor C16 and C17. When the Vcc voltage exceeds the UVLO at 17V, the IC starts up. Then the Vcc voltage is bootstrapped by the auxiliary winding to sustain the operation. 5.4 Operation mode During operation, the Vcc pin is supplied via a separate transformer winding with associated rectification D12 and buffering C16, C17. In order not to exceed the maximum voltage at Vcc pin, an external zener diode ZD11 and resistor R14 can be added. 5.5 Soft start The Soft-Start is a built-in function and is set at 10ms. 5.6 RCD clamper circuit While turns off the CoolMOS®, the clamper circuit R11, C14 and D11 absorbs the current caused by transformer leakage inductance once the voltage exceeds clamp capacitor voltage. Finally drain-source voltage of CoolMOS® is lower than maximum break down voltage (V(BR)DSS = 800V) of CoolMOS®. 5.7 Peak current control of primary current The CoolMOS® drain source current is sensed via external shunt resistors R15 and R16 which determine the tolerance of the current limit control. Since ICE3AR2280JZ is a current mode controller, it would have a cycle-by-cycle primary current and feedback voltage control and can make sure the maximum power of the converter is controlled in every switching cycle. Besides, the patented propagation delay compensation is implemented to ensure the maximum input power can be controlled in an even tighter manner thoughout the wide range input voltage. The demo board shows approximately. +/-3.86% (refer to Figure 14). 20W 5V Demoboard using ICE3AR2280JZ Application Note 9 2010-08-11 5.8 Output stage On the secondary side the power is coupled out by a schottky diode D21. The capacitor C21 & C22 provide energy buffering following with the LC filter L21 and C23 to reduce the output voltage ripple considerably. Storage capacitors C21 & C22 are selected to have a very small internal resistance (ESR) to minimize the output voltage ripple. The optional common mode choke L22 and ceramic capacitor C24 are added to suppress the high voltage electrostatic static charge during ESD test. 5.9 Feedback and burst entry/exit control FBB pin has 2 features; functions of output voltage feedback and burst entry control. The output voltage is controlled by using a TL431 (IC21) which incorporates the voltage reference as well as the error amplifier and a driver stage. Compensation network C26, C27, R23, R24, R25, R26 and R27 constitutes the external circuitry of the error amplifier of IC21. This circuitry allows the feedback to be precisely matched to dynamically varying load conditions and provides stable control. The maximum current through the optocoupler diode and the voltage reference is set by using resistors R21 and R22. Optocoupler IC12 is used for floating transmission of the control signal to the “Feedback” input of the ICE3AR2280JZ. The capacitor C19 at the FBB pin acts 2 functions; filter the noise from going to the pin and setting for the selection of the burst entry control (explained below). The optocoupler used meets DIN VDE 884 requirements for a wider creepage distance. C19 capacitor is also used to select the entry and exit burst level. The IC would generate the charge and discharge current to the FBB pin and then detect the number of count for the charge and discharge cycle during the 1st 1ms of IC start up (Vcc > 17V). Based on the detected number of count, the entry and exit burst level are set. The below table is the recommended capacitance range for the entry and exit level with the CFB (C19) capacitor. Entry level Exit level CFB Corresponding no. of counts % of Pin_max VFB_burst % of Pin_max Vcsth_burst ≥ 6.8nF ≤ 7 10% 1.6V 20% 0.45V 1nF~2.2nF 8 ~ 39 6.67% 1.42V 13.30% 0.37V 220pF~470pF 40 ~ 91 4.38% 1.27V 9.60% 0.31V ≤100pF ≥ 92 0 never 0 always 5.10 Blanking window for load jump In case of load jumps the controller provides a blanking window before activating the Over Load Protection and entering the Auto Restart Mode. There are 2 modes for the blanking time setting; basic mode and the extendable mode. If there is no capacitor added to the BBA pin, it would fall into the basic mode; i.e. the blanking time is set at 20ms. If a longer blanking time is required, a capacitor, CBK (C18) can be added to BBA pin to extend it. The extended blanking time can be achieved by the lead time of 256 times of charging and discharging of CBK capacitor, which is generated by the controller. Thus the overall blanking time is the addition of 20ms and the extended time. For example, CBK (C18) = 0.22uF, Ichg_EB (internal charging current) = 720uA msC I CmsExtendedBasict BK EBchg BK blanking 9.346)9.0 5.4ln(500)9.05.4(25620 _ =              ××+    ×−×+=+= Since the BBA pin is multi-function pin, extended blanking time can be changed if the brownout resistor R110 ( 28kΩ ) is added to the system, new Ichg_EB‘ and overall blanking time can be calculated as follows, A R AI BO EBchg µµ 6.623*2 )9.05.4(720' 2 _ =+−= 20W 5V Demoboard using ICE3AR2280JZ Application Note 10 2010-08-11 msC I Cmst BK EBchg BK Rblanking BO 4.390) 9.0 5.4ln(500 ' )9.05.4(25620 _ _ 2 =            