ICE2QS03HKLA1

Da ta s h e e t, Ve rs i o n 2 . 2, Ju l y 4 , 2 0 1 1 Q u a s i- R e s o na n t C on t r o ll er PWM Po we r M an a ge me nt & Su pp l y N e v e r s t o p t h i n k i n g . ICE2QS03 Revision History: July 4, 2011 Previous Version: 2.1 Page18 Datasheet Updated outline dimension For questions on technology, delivery and prices please contact the Infineon Technologies Offices in Germany or the Infineon Technologies Companies and Representatives worldwide: see our webpage at http:// www.infineon.com CoolMOS®, CoolSET® are trademarks of Infineon Technologies AG. Edition July 4, 2011 Published by Infineon Technologies AG 81726 München, Germany © Infineon Technologies AG 7/4/11. All Rights Reserved. Attention please! The information given in this data sheet shall in no event be regarded as a guarantee of conditions or characteristics (“Beschaffenheitsgarantie”). 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 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. ICE2QS03 Quasi-Resonant PWM Controller Product Highlight • Active burst mode for low standby power • Digital frequency reduction for better overall system efficiency • Integrated power cell for IC self-power supply DIP-8 Features Description • • ICE2QS03 is a quasi-resonant PWM controller optimized for off-line switch power supply applications such as LCD TV, CRT TV and notebook adapter. The digital frequency reduction with decreasing load enables a quasi-resonant operation till very low load. As a result, the overall system efficiency is significantly improved compared to other conventional solutions. The active burst mode operation enables an ultra-low power consumption at standby mode with small and controllable output voltage ripple. Based on the BiCMOS technology, the product has a wide operation range (up to 26V) of IC power supply and lower power consumption. The numerous protection functions give a full protection of the power supply system in failure situations. All of these make the ICE2QS03 an outstanding controller for quasi-resonant flyback converter in the market. • • • • • • • • • Quasiresonant operation till very low load Active burst mode operation at light/no load for low standby input power (< 100mW) Digital frequency reduction with decreasing load Power cell for VCC pre-charging with constant current Built-in digital soft-start Foldback correction and cycle-by-cycle peak current limitation Auto restart mode for VCC Overvoltage protection Auto restart mode for VCC Undervoltage protection Auto restart mode for openloop/overload protection Latch-off mode for adjustable output overvoltage protection Latch-off mode for Short-winding protection Typical Application Circuit Wp Snubber Cbus 85 ~ 265Vac RVCC Lf DO DVCC CVCC VO Cf Ws CO RZC2 RZC1 Wa Dr1~Dr4 CZC HV VCC ZC CPS Power Cell Q1 Rb1 CDS GND Control Unit Zero Crossing Detection Active Burst Mode FB GATE Rb2 Power Management Digital Process Block CFB Gate Driver Optocoupler Current Limitation Rovs1 Rc1 CS Protection Block RCS Current Mode Control ICE2QS03 Cc1 Cc2 TL431 Rovs2 Type ICE2QS03 Version 2.2 Marking ICE2QS03 3 Package PG-DIP-8 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Table of Contents Page 1 1.1 1.2 1.3 Pin Configuration and Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Pin Configuration with PG-DIP-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Package PG-DIP-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Pin Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 2 Representative Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 3 3.1 3.2 3.3 3.3.1 3.3.1.1 3.3.1.2 3.3.2 3.3.3 3.4 3.4.1 3.5 3.5.1 3.5.2 3.5.3 3.6 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 VCC Pre-Charging and Typical VCC Voltage During Start-up . . . . . . . . . . .7 Soft-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Digital Frequency Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Up/down counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Zero crossing (ZC counter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Ringing suppression time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Switch Off Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Current Limitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Foldback Point Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Active Burst Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Entering Active Burst Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . .10 During Active Burst Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Leaving Active Burst Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Protection Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 4 4.1 4.2 4.3 4.3.1 4.3.2 4.3.3 4.3.4 4.3.5 4.3.6 4.3.7 4.3.8 4.3.9 4.3.10 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Supply Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Internal Voltage Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 PWM Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Current Sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Soft Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Foldback Point Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Digital Zero Crossing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Active Burst Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Gate Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 5 Outline Dimension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Version 2.2 4 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Pin Configuration and Functionality 1 Pin Configuration and Functionality 1.1 1.3 ZC (Zero Crossing) At this pin, the voltage from the auxiliary winding after a time delay circuit is applied. Internally, this pin is connected to the zero-crossing detector for switch-on determination. Additionally, the output overvoltage detection is realized by comparing the voltage Vzc with an internal preset threshold. Pin Configuration with PG-DIP8 Pin Symbol Function 1 ZC Zero Crossing 2 FB Feedback 3 CS Current Sense 4 HV High Voltage Input 5 HV High Voltage Input 6 GATE Gate Drive Output 7 VCC Controller Supply Voltage 8 GND Controller Ground 1.2 FB (Feedback) Normally, an external capacitor is connected to this pin for a smooth voltage VFB. Internally, this pin is connected to the PWM signal generator for switch-off determination (together with the current sensing signal), the digital signal processing for the frequency reduction with decreasing load during normal operation, and the Active Burst Mode controller for entering Active Burst Mode operation determination and burst ratio control during Active Burst Mode operation. Additionally, the open-loop / over-load protection is implemented by monitoring the voltage at this pin. CS (Current Sense) This pin is connected to the shunt resistor for the primary current sensing, externally, and the PWM signal generator for switch-off determination (together with the feedback voltage), internally. Moreover, shortwinding protection is realised by monitoring the voltage Vcs during on-time of the main power switch. Package PG-DIP-8 ZC 1 8 GND FB 2 7 VCC CS 3 6 GATE HV 4 5 HV Figure 1 Pin Functionality GATE (Gate Drive Output) This output signal drives the external main power switch, which is a power MOSFET in most case. HV (High Voltage) The pin HV is connected to the bus voltage, externally, and to the power cell, internally. The current through this pin pre-charges the VCC capacitor with constant current once the supply bus voltage is applied. VCC (Power supply) VCC pin is the positive supply of the IC. The operating range is between VVCCoff and VVCCOVP. Pin Configuration PG-DIP-8(top view) GND (Ground) This is the common ground of the controller. Version 2.2 5 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Representative Block diagram 2 Representative Block diagram Figure 2 Version 2.2 Representative Block diagram 6 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Functional Description 3 Functional Description then will reach a constant value depending on output load. 3.1 VCC Pre-Charging and Typical VCC Voltage During Start-up 3.2 At the time ton, the IC begins to operate with a soft-start. By this soft-start the switching stresses for the switch, diode and transformer are minimised. The soft-start implemented in ICE2QS03 is a digital time-based function. The preset soft-start time is 12ms with 4 steps. If not limited by other functions, the peak voltage on CS pin will increase step by step from 0.32V to 1V finally. In ICE2QS03, a high voltage startup cell is integrated. As shown in Figure 2, the start cell consists of a high voltage device and a controller, whereby the high voltage device is controlled by the controller. The startup cell provides a pre-charging of the VCC capacitor till VCC voltage reaches the VCC turned-on threshold VVCCon and the IC begins to operate. Once the mains input voltage is applied, a rectified voltage shows across the capacitor Cbus. The high voltage device provides a current to charge the VCC capacitor Cvcc. Before the VCC voltage reaches a certain value, the amplitude of the current through the high voltage device is only determined by its channel resistance and can be as high as several mA. After the VCC voltage is high enough, the controller controls the high voltage device so that a constant current around 1mA is provided to charge the VCC capacitor further, until the VCC voltage exceeds the turned-on threshold VVCCon. As shown as the time phase I in Figure 3, the VCC voltage increase near linearly and the charging speed is independent of the mains voltage level. Vcs_sst (V) 1.00 0.83 0.66 0.49 0.32 ton Figure 4 VVCC VVCCon i ii 3.3 iii Figure 3 t2 t VCC voltage at start up The time taking for the VCC pre-charging can then be approximately calculated as: t V ×C VCCon vcc = -----------------------------------------1 I VCCch arg e2 [1] where IVCCcharge2 is the charging current from the startup cell which is 1.05mA, typically. Exceeds the VCC voltage the turned-on threshold VVCCon of at time t1, the startup cell is switched off, and the IC begins to operate with a soft-start. Due to power consumption of the IC and the fact that still no energy from the auxiliary winding to charge the VCC capacitor before the output voltage is built up, the VCC voltage drops (Phase II). Once the output voltage is high enough, the VCC capacitor receives then energy from the auxiliary winding from the time point t2 on. The VCC Version 2.2 3 6 9 12 Time(ms) Maximum current sense voltage during softstart Normal Operation The PWM controller during normal operation consists of a digital signal processing circuit including an up/ down counter, a zero-crossing counter (ZC counter) and a comparator, and an analog circuit including a current measurement unit and a comparator. The switch-on and -off time points are each determined by the digital circuit and the analog circuit, respectively. As input information for the switch-on determination, the zero-crossing input signal and the value of the up/down counter are needed, while the feedback signal VFB and the current sensing signal VCS are necessary for the switch-off determination. Details about the full operation of the PWM controller in normal operation are illustrated in the following paragraphs. VVCCoff t1 Soft-start 3.3.1 Digital Frequency Reduction As mentioned above, the digital signal processing circuit consists of an up/down counter, a ZC counter and a comparator. These three parts are key to implement digital frequency reduction with decreasing load. In addition, a ringing suppression time controller is implemented to avoid mistriggering by the high frequency oscillation, when the output voltage is very low under conditions such as soft start or output short circuit . Functionality of these parts is described as in the following. 7 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Functional Description threshold voltages, VFBZL and VFBZH, are changed internally depending on the line voltage levels. 3.3.1.1 Up/down counter The up/down counter stores the number of the zero crossing to be ignored before the main power switch is switched on after demagnetisation of the transformer. This value is fixed according to the feedback voltage, VFB, which contains information about the output power. Indeed, in a typical peak current mode control, a high output power results in a high feedback voltage, and a low output power leads to a low regulation voltage. Hence, according to VFB, the value in the up/ down counter is changed to vary the power MOSFET off-time according to the output power. In the following, the variation of the up/down counter value according to the feedback voltage is explained. The feedback voltage VFB is internally compared with three threshold voltages VRL, VRH and VRM, at each clock period of 48ms. The up/down counter counts then upward, keep unchanged or count downward, as shown in Table 1. up/down counter action Always lower than VFBZL Count upwards till 7 Once higher than VFBZL, but always lower than VFBZH Stop counting, no value changing Once higher than VFBZH, but always lower than VFBR1 Count downwards till 1 Once higher than VFBR1 VFBR1 VFBZH VFBZL n+2 n+2 n+2 n+2 n+1 n n-1 t n+1 Up/down counter Case 1 4 5 6 6 6 6 5 4 3 1 Case 2 2 3 4 4 4 4 3 2 1 1 Case 3 7 7 7 7 7 7 6 5 4 1 Figure 5 1 Up/down counter operation 3.3.1.2 Zero crossing (ZC counter) In the system, the voltage from the auxiliary winding is applied to the zero-crossing pin through a RC network, which provides a time delay to the voltage from the auxiliary winding. Internally, this pin is connected to a clamping network, a zero-crossing detector, an output overvoltage detector and a ringing suppression time controller. During on-state of the power switch a negative voltage applies to the ZC pin. Through the internal clamping network, the voltage at the pin is clamped to certain level. The ZC counter has a minimum value of 0 and maximum value of 7. After the internal MOSFET is turned off, every time when the falling voltage ramp of on ZC pin crosses the 100mV threshold, a zero crossing is detected and ZC counter will increase by 1. It is reset every time after the GATE output is changed to high. The voltage vZC is also used for the output overvoltage protection. Once the voltage at this pin is higher than the threshold VZCOVP during off-time of the main switch, the IC is latched off after a fixed blanking time. To achieve the switch-on at voltage valley, the voltage from the auxiliary winding is fed to a time delay network (the RC network consists of Dzc, Rzc1, Rzc2 and Czc as shown in typical application circuit) before it is applied to the zero-crossing detector through the ZC pin. The needed time delay to the main oscillation signal Dt should be approximately one fourth of the oscillation period (by transformer primary inductor and drainsource capacitor) minus the propagation delay from Set up/down counter to 1 In the ICE2QS03, the number of zero crossing is limited to 7. Therefore, the counter varies between 1 and 7, and any attempt beyond this range is ignored. When VFB exceeds VFBR1 voltage, the up/down counter is initialised to 1, in order to allow the system to react rapidly to a sudden load increase. The up/down counter value is also intialised to 1 at the start-up, to ensure an efficient maximum load start up. Figure 5 shows some examples on how up/down counter is changed according to the feedback voltage over time. The use of two different thresholds VFBZL and VFBZH to count upward or downward is to prevent frequency jittereing when the feedback voltage is close to the threshold point. However, for a stable operation, these two thresholds must not be affected by the foldback current limitation (see Section 3.4.1), which limits the VCS voltage. Hence, to prevent such situation, the Version 2.2 t VFB Operation of the up/down counter vFB T=48ms n Table 1 clock 8 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Functional Description thedetected zero-crossing to the switch-on of the main switch tdelay, theoretically: T osc Dt = ------------ – t delay 4 To avoid mistriggering caused by the voltage spike across the shunt resistor at the turn on of the main power switch, a leading edge blanking time, tLEB, is applied to the output of the comparator. In other words, once the gate drive is turned on, the minimum on time of the gate drive is the leading edge blanking time. In addition, there is a maximum on time, tOnMax, limitation implemented in the IC. Once the gate drive has been in high state longer than the maximum on time, it will be turned off to prevent the switching frequency from going too low because of long on time. [2] This time delay should be matched by adjusting the time constant of the RC network which is calculated as: t td = C R ×R zc1 zc2× -------------------------------zc R +R zc1 zc2 [3] 3.4 3.3.2 Ringing suppression time After MOSFET is turned off, there will be some oscillation on VDS, which will also appear on the voltage on ZC pin. To avoid that the MOSFET is turned on mistriggerred by such oscillations, a ringing suppression timer is implemented. The timer is dependent on the voltage vZC. When the voltage vZC is lower than the threshold VZCRS, a longer preset time applies, while a shorter time is set when the voltage vZC is higher than the threshold. There is a cycle by cycle current limitation realized by the current limit comparator to provide an overcurrent detection. The source current of the MOSFET is sensed via a sense resistor RCS. By means of RCS the source current is transformed to a sense voltage VCS which is fed into the pin CS. If the voltage VCS exceeds an internal voltage limit, adjusted according to the Mains voltage, the comparator immediately turns off the gate drive. To prevent the Current Limitation process from distortions caused by leading edge spikes, a Leading Edge Blanking time (tLEB) is integrated in the current sensing path. A further comparator is implemented to detect dangerous current levels (VCSSW) which could occur if one or more transformer windings are shorted or if the secondary diode is shorted. To avoid an accidental latch off, a spike blanking time of tCSSW is integrated in the output path of the comparator . 3.3.2.1 Switch on determination After the gate drive goes to low, it can not be changed to high during ring suppression time. After ring suppression time, the gate drive can be turned on when the ZC counter value is higher or equal to up/down counter value. However, it is also possible that the oscillation between primary inductor and drain-source capacitor damps very fast and IC can not detect enough zero crossings and ZC counter value will not be high enough to turn on the gate drive. In this case, a maximum off time is implemented. After gate drive has been remained off for the period of TOffMax, the gate drive will be turned on again regardless of the counter values and VZC. This function can effectively prevent the switching frequency from going lower than 20kHz, otherwise which will cause audible noise, during start up. 3.4.1 Foldback Point Correction When the main bus voltage increases, the switch on time becomes shorter and therefore the operating frequency is also increased. As a result, for a constant primary current limit, the maximum possible output power is increased, which the converter may have not been designed to support. To avoid such a situation, the internal foldback point correction circuit varies the VCS voltage limit according to the bus voltage. This means the VCS will be decreased when the bus voltage increases. To keep a constant maximum input power of the converter, the 3.3.3 Switch Off Determination In the converter system, the primary current is sensed by an external shunt resistor, which is connected between low-side terminal of the main power switch and the common ground. The sensed voltage across the shunt resistor vCS is applied to an internal current measurement unit, and its output voltage V1 is compared with the regulation voltage VFB. Once the voltage V1 exceeds the voltage VFB, the output flip-flop is reset. As a result, the main power switch is switched off. The relationship between the V1 and the vCS is described by: V 1 = 3.3 × V CS + 0.7 Version 2.2 Current Limitation [4] 9 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Functional Description required maximum VCS versus various input bus voltage can be calculated, which is shown in Figure 6. about Active Burst Mode operation are explained in the following paragraphs. 3.5.1 Entering Active Burst Mode Operation For determination of entering Active Burst Mode operation, three conditions apply: • the feedback voltage is lower than the threshold of VFBEB(1.25V). Accordingly, the peak current sense voltage across the shunt resistor is 0.17; • the up/down counter is 7; and • a certain blanking time (tBEB). Once all of these conditions are fulfilled, the Active Burst Mode flip-flop is set and the controller enters Active Burst Mode operation. This multi-condition determination for entering Active Burst Mode operation prevents mistriggering of entering Active Burst Mode operation, so that the controller enters Active Burst Mode operation only when the output power is really low during the preset blanking time. 1 Vcs-max(V) 0.9 0.8 0.7 0.6 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 Vin(V) Figure 6 Variation of the VCS limit voltage according to the IZC current According to the typical application circuit, when MOSFET is turned on, a negative voltage proportional to bus voltage will be coupled to auxiliary winding. Inside ICE2QS03, an internal circuit will clamp the voltage on ZC pin to nearly 0V. As a result, the current flowing out from ZC pin can be calculated as I V N BUS a = -----------------------ZC R ZC1 N P 3.5.2 During Active Burst Mode Operation After entering the Active Burst Mode the feedback voltage rises as VOUT starts to decrease due to the inactive PWM section. One comparator observes the feedback signal if the voltage level VBH (3.6V) is exceeded. In that case the internal circuit is again activated by the internal bias to start with swtiching. Turn-on of the power MOSFET is triggered by the timer. The PWM generator for Active Burst Mode operation composes of a timer with a fixed frequency of 52kHz, typically, and an analog comparator. Turn-off is resulted by comparison of the voltage signal v1 with an internal threshold, by which the voltage across the shunt resistor VcsB is 0.34V, accordingly. A turn-off can also be triggered by the maximal duty ratio controller which sets the maximal duty ratio to 50%. In operation, the output flip-flop will be reset by one of these signals which come first. If the output load is still low, the feedback signal decreases as the PWM section is operating. When feedback signal reaches the low threshold VBL(3.0V), the internal bias is reset again and the PWM section is disabled until next time regultaion siganl increases beyond the VBH threshold. If working in Active Burst Mode the feedback signal is changing like a saw tooth between 3.0V and 3.6V shown in Figure 7. [5] When this current is higher than IZC_1, the amount of current exceeding this threshold is used to generate an offset to decrease the maximum limit on VCS. Since the ideal curve shown in Figure 6 is a nonlinear one, a digital block in ICE2QS03 is implemented to get a better control of maximum output power. Additional advantage to use digital circuit is the production tolerance is smaller compared to analog solutions. The typical maximum limit on VCS versus the ZC current is shown in Figure 7. 1 Vcs-max(V) 0.9 0.8 0.7 3.5.3 Leaving Active Burst Mode Operation The feedback voltage immediately increases if there is a high load jump. This is observed by one comparator. As the current limit is 34% during Active Burst Mode a certain load is needed so that feedback voltage can exceed VLB (4.5V). After leaving active busrt mode, maximum current can now be provided to stabilize VO. In addition, the up/down counter will be set to 1 0.6 300 500 700 900 1100 1300 1500 1700 1900 2100 Iz c(uA) Figure 7 3.5 VCS-max versus IZC Active Burst Mode Operation At light load condition, the IC enters Active Burst Mode operation to minimize the power consumption. Details Version 2.2 10 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Functional Description immediately after leaving Active Burst Mode. This is helpful to decrease the output voltage undershoot. VFB Leaving Active Burst Mode Entering Active Burst Mode VFBLB VFBBOn VFBBOff IC is reset and the main power switch is then kept off. After the VCC voltage falls below the threshold VVCCoff, the startup cell is activated. The VCC capacitor is then charged up. Once the voltage exceeds the threshold VVCCon, the IC begins to operate with a new soft-start. In case of open control loop or output over load, the feedback voltage will be pulled up . After a blanking time of 24ms, the IC enters auto-restart mode. The blanking time here enables the converter to provide a high power in case the increase in VFB is due to a sudden load increase. During off-time of the power switch, the voltage at the zero-crossing pin is monitored for output over-voltage detection. If the voltage is higher than the preset threshold vZCOVP, the IC is latched off after the preset blanking time. If the junction temperature of IC exceeds 140 °C, the IC enter into autorestart mode. If the voltage at the current sensing pin is higher than the preset threshold vCSSW during on-time of the power switch, the IC is latched off. This is short-winding protection. During latch-off protection mode, when the VCC voltage drops to 10.5V,the startup cell is activated and the VCC voltage is charged to 18V then the startup cell is shut down again and repeats the previous procedure. There is also an maximum on time limitation inside ICE2QS03. Once the gate voltage is high longer than tOnMAx, it is turned off immediately. VFBEB Blanking Window (tBEB) t VCS 1.0V Current limit level during Active Burst Mode VCSB VVCC t VVCCoff VO t Max. Ripple < 1% t Figure 8 3.6 Signals in Active Burst Mode Protection Functions The IC provides full protection functions. The following table summarizes these protection functions. Table 2 Protection features VCC Overvoltage Auto Restart Mode VCC Undervoltage Auto Restart Mode Overload/Open Loop Auto Restart Mode Over temperature Auto Restart Mode Output Overvoltage Latched Off Mode Short Winding Latched Off Mode During operation, the VCC voltage is continuously monitored. In case of an under- or an over-voltage, the Version 2.2 11 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Electrical Characteristics 4 Electrical Characteristics Note: All voltages are measured with respect to ground (Pin 8). The voltage levels are valid if other ratings are not violated. 4.1 Note: Absolute Maximum Ratings Absolute maximum ratings are defined as ratings, which when being exceeded may lead to destruction of the integrated circuit. For the same reason make sure, that any capacitor that will be connected to pin 7 (VCC) is discharged before assembling the application circuit. Parameter Symbol Limit Values min. max. Unit Remarks HV Voltage VHV - 500 V VCC Supply Voltage VVCC -0.3 27 V FB Voltage VFB -0.3 5.0 V ZC Voltage VZC -0.3 5.0 V CS Voltage VCS -0.3 5.0 V GATE Voltage VOUT -0.3 27 V Maximum current out from ZC pin IZCMAX 3 - mA Junction Temperature Tj -40 125 °C Storage Temperature TS -55 150 °C Thermal Resistance Junction -Ambient RthJA - 90 K/W PG-DIP-8 ESD Capability (incl. Drain Pin) VESD - 2 kV Human body model1) 1) According to EIA/JESD22-A114-B (discharging a 100pF capacitor through a 1.5kW series resistor) 4.2 Note: Operating Range Within the operating range the IC operates as described in the functional description. Parameter Symbol Limit Values min. max. Unit VCC Supply Voltage VVCC VVCCoff VVCCOVP V Junction Temperature of Controller TjCon -25 125 Version 2.2 12 Remarks °C July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Electrical Characteristics 4.3 4.3.1 Note: Characteristics Supply Section The electrical characteristics involve the spread of values within the specified supply voltage and junction temperature range TJ from – 25 °C to 125 °C. Typical values represent the median values, which are related to 25°C. If not otherwise stated, a supply voltage of VCC = 18 V is assumed. Parameter Symbol Limit Values min. typ. max. Unit Test Condition Start Up Current IVCCstart - 300 550 mA VVCC =VVCCon -0.2V VCC Charge Current IVCCcharge1 - 5.0 - mA VVCC = 0V IVCCcharge2 0.8 - - mA VVCC = 1V IVCCcharge3 - 1.0 - mA VVCC =VVCCon -0.2V Maximum Input Current of Startup Cell and CoolMOS® IDrainIn - - 2 mA VVCC =VVCCon -0.2V Leakage Current of Startup Cell and CoolMOS® IDrainLeak - 0.2 50 mA VDrain = 610V at Tj=100°C Supply Current in normal operation IVCCNM - 1.5 2.3 mA output low Supply Current in Auto Restart Mode with Inactive Gate IVCCAR - 300 - mA IFB = 0A Supply Current in Latch-off Mode IVCClatch - 300 - mA Supply Current in Burst Mode with inactive Gate IVCCburst - 500 950 mA VCC Turn-On Threshold VVCCon 17.0 18.0 19.0 V VCC Turn-Off Threshold VVCCoff 9.8 10.5 11.2 V VCC Turn-On/Off Hysteresis VVCChys - 7.5 - V 4.3.2 VFB = 2.5V, exclude the current flowing out from FB pin Internal Voltage Reference Parameter Internal Reference Voltage Version 2.2 Symbol VREF Limit Values min. typ. max. 4.80 5.00 5.20 13 Unit Test Condition V Measured at pin FB IFB=0 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Electrical Characteristics 4.3.3 PWM Section Parameter Symbol Limit Values min. typ. max. Unit Feedback Pull-Up Resistor RFB 14 23 33 kW PWM-OP Gain GPWM 3.18 3.3 - - Offset for Voltage Ramp VPWM 0.63 0.7 - V Maximum on time in normal operation tOnMax 22 30 41 ms 4.3.4 Current Sense Parameter Symbol Limit Values min. typ. max. Unit Peak current limitation in normal operation VCSth 0.97 1.03 1.09 V Leading Edge Blanking time tLEB 200 330 460 ns Peak Current Limitation in Active Burst Mode VCSB 0.29 0.34 0.39 V 4.3.5 Test Condition Soft Start Parameter Symbol Limit Values min. typ. max. Unit Soft-Start time tSS 8.5 12 - ms soft-start time step tSS_S1) - 3 - ms Internal regulation voltage at first step VSS11) - 1.76 - V Internal regulation voltage step at soft start VSS_S1) - 0.56 - V 1) Test Condition Test Condition The parameter is not subjected to production test - verified by design/characterization 4.3.6 Foldback Point Correction Parameter Symbol Limit Values min. typ. max. Unit ZC current first step threshold IZC_FS 0.35 0.5 0.621 mA ZC current last step threshold IZC_LS 1.8 2 2.2 mA CS threshold minimum VCSMF - 0.66 - V Version 2.2 14 Test Condition Izc=2.2mA, VFB=3.8V July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Electrical Characteristics 4.3.7 Digital Zero Crossing Parameter Symbol Limit Values Unit Test Condition min. typ. max. Zero crossing threshold voltage VZCCT 50 100 170 mV Ringing suppression threshold VZCRS - 0.7 - V Minimum ringing suppression time tZCRS1 1.8 2.5 3.4 ms VZC > VZCRS Maximum ringing suppression time tZCRS2 - 25 - ms VZC < VZCRS Threshold to set Up/Down Counter to one VFBR1 - 3.9 - V Threshold for downward counting at low line VFBZHL - 3.2 - V Threshold for upward counting at low line VFBZLL - 2.5 - V Threshold for downward counting at hig line VFBZHH - 2.9 - V Threshold for upward counting at highline VFBZLH - 2.3 - V ZC current for IC switch threshold to high line IZCSH - 1.3 - mA ZC current for IC switch threshold to low line IZCSL - 0.8 - mA Counter time1) tCOUNT - 48 - ms Maximum restart time in normal operation tOffMax 30 42 57.5 ms 1) The parameter is not subjected to production test - verified by design/characterization Version 2.2 15 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Electrical Characteristics 4.3.8 Active Burst Mode Parameter Symbol Limit Values min. typ. max. Unit Feedback voltage for entering Active Burst Mode VFBEB - 1.25 - Minimum Up/down value for entering Active Burst Mode NZC_ABM - 7 - Blanking time for entering Active Burst Mode tBEB - 24 - ms Feedback voltage for leaving Active Burst Mode VFBLB - 4.5 - V Feedback voltage for burst-on VFBBOn - 3.6 - V Feedback voltage for burst-off VFBBOff - 3.0 - V Fixed Switching Frequency in Active Burst Mode fsB - 52 - kHz Max. Duty Cycle in Active Burst Mode DmaxB - 0.5 - 4.3.9 V Protection Parameter Symbol Limit Values min. typ. max. Unit VCC overvoltage threshold VVCCOVP 24.0 25.0 26.0 V Over Load or Open Loop Detection threshold for OLP protection at FB pin VFBOLP - 4.5 - V Over Load or Open Loop Protection Blanking Time tOLP_B 20 30 44 ms Output Overvoltage detection threshold at the ZC pin VZCOVP 3.55 3.7 3.84 V Blanking time for Output Overvoltage protection tZCOVP - 100 - ms Threshold for short winding protection VCSSW 1.63 1.68 1.78 V Blanking time for short-windding protection tCSSW - 190 - ns Over temperature protection1) TjCon - 140 - 0 Note: Test Condition Test Condition C The trend of all the voltage levels in the Control Unit is the same regarding the deviation except VVCCOVP Version 2.2 16 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Electrical Characteristics 4.3.10 Gate Drive Parameter Symbol Limit Values min. typ. max. Unit Test Condition Output voltage at logic low VGATElow - - 1.0 V VVCC=18V IOUT = 10mA Output voltage at logic high VGATEhigh 9.0 10.0 - V VVCC=18V IOUT = -10mA Output voltage active shut down VGATEasd - - 1.0 V V VVCC = 7V IOUT = 10mA Rise Time trise - 117 - ns COUT = 1.0nF VGATE= 2V ... 8V Fall Time tfall - 27 - ns COUT = 1.0nF VGATE= 8V ... 2V Version 2.2 17 July 4, 2011 Quasi-Resonant PWM Controller ICE2QS03 Outline Dimension 5 Outline Dimension PG-DIP-8 (Leadfree Plastic Dual In-Line Outline) Figure 9 Version 2.2 PG-DIP-8 (Pb-free lead plating Plastic Dual-in-Line Outline) 18 July 4, 2011 Total Quality Management Qualität hat für uns eine umfassende Bedeutung. Wir wollen allen Ihren Ansprüchen in der bestmöglichen Weise gerecht werden. Es geht uns also nicht nur um die Produktqualität – unsere Anstrengungen gelten gleichermaßen der Lieferqualität und Logistik, dem Service und Support sowie allen sonstigen Beratungs- und Betreuungsleistungen. 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