ICB2FL02G PG-DSO-19-1 OS-KLTN-03 DALI-AG-03 180VAC 270VAC SPD03N60C3 MURS160T3 - Datasheet Archive

 

ICB2FL02G Smart Ballast Control IC for Flourescent Lamp Ballasts Dimming Demoboard 26W TC-TEL Single Lamp Design

 

Application Note, Rev. 1.0, August 2009 ICB2FL02G ICB2FL02G Smart Ballast Control IC for Flourescent Lamp Ballasts Dimming Demoboard 26W TC-TEL Single Lamp Design www.infineon.com/smartlighting Edition 2009-08-07 Published by Infineon Technologies AG 81726 Munich, Germany © 2009 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. Application Note - ICB2FL02G ICB2FL02G Table 1 ICB2FL02G ICB2FL02G Revision History: 2009-08-07, Rev. 1.0 Previous Version: Page Subjects (major changes since last revision) Application Note 3 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Contents Contents Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Product Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Features PFC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Features Lamp Ballast Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1 1.1 1.2 1.2.1 1.2.2 1.2.3 1.2.4 Dimming - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Characteristics of low-pressure discharge lamps Switch-on to dimming . . . . . . . . . . . . . . . . . . . . . . . 6 Overview of dimming options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Power control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1-10V interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 DALI (Digital Addressable Lighting Interface) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 2.1 2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 Dimming with the ICB2FL02G ICB2FL02G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Matching the heating circuit for cathode heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operating principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10V interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lamp current sensing for the actual value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Regulating circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dimming characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Layout, schematic and BOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4 Bibliographic references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Application Note 4 11 11 13 13 15 15 17 19 Rev. 1.0, 2009-08-07 Smart Ballast Control IC for Flourescent Lamp Ballasts Dimming Demoboard 26W TC-TEL Single Lamp Design ICB2FL02G ICB2FL02G Product Highlights · · · · · · · · · Lowest Count of external Components 900V-Half-Bridge driver with Coreless Transformer Technology Supports Customer In-Circuit Test Mode for reduced Tester Time Supports Multi-Lamp Designs Integrated digital Timers up to 40 seconds Numerous Monitoring and Protection Features for highest Reliability Very high accuracy of frequencies and timers over the whole temperature range Very low standby losses Special detection thresholds for dimming applications Features PFC · · · · Discontinuous Mode PFC for Load Range 0 to 100% Integrated digital Compensation of PFC Control Loop Improved Compensation for low THD of AC Input Current also in DCM operation Adjustable PFC Current Limitation Features Lamp Ballast Inverter · · · · · · Adjustable Detection of Overload and Rectifier Effect (EOL) Detection of Capacitive Load operation Improved Ignition control allows for operation close to magnetic saturation of Inductors Restart with skipped Preheating at short interruptions of Line Voltage (for Emergency Lighting) Parameters adjustable by resistors only Pb-free Lead Plating; RoHS compliant Type Package ICB2FL02G ICB2FL02G PG-DSO-19-1 PG-DSO-19-1 (300mil) Application Note 5 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming - Introduction 1 Dimming - Introduction The fluorescent lamp ballast Controller ICB2FL02G ICB2FL02G is designed to control a boost converter as an active power factor correction (PFC) filter in critical/discontinuous conduction mode (CritCM/DCM) and a half-bridge topology as a lamp inverter with special detection thresholds for dimming applications. The intelligent control concept enables designers to develop cost-effective dimmable ballasts for fluorescent lamps (FL) that fulfil the requirements of a high performance T5 lamp ballast as well as multi lamp topologies, T8 and T4 designs. A state machine controlling the operating modes, a completely integrated digital control loop for the PFC output voltage and low tolerances for reference voltages and operating frequency over the whole temperature range are a result of the advanced mixed signal technology with only few required components externally. Combined with a high voltage level shift driver with Coreless Transformer Technology for the half-bridge inverter the IC offers a significant number of exceptional features for FL ballasts. The FL-Ballast Controller ICB2FL02G ICB2FL02G has an improved and enlarged functionality that enables dimmable and high quality single or multi lamp ballasts with a low number of external components. Its benefit is to save system costs and to reach class A2 of the energy efficiency index (EEI) for fluorescent lamp ballasts easily. This Application Note describes how an electronic ballast can be enhanced using the ICB2FL02G ICB2FL02G Smart Ballast controller to produce a dimmable electronic ballast. Figure 1 shows a picture of the Demoboard. The described circuitry is an example to demonstrate the principle of dimming with the ICB2FL02G ICB2FL02G. The dimming range is down to about 5% of maximal brightness. There are no limitations of the IC to realise dimming ballasts with much lower brightness levels. Figure 1 Picture of the dimmable Demoboard A brief introduction of the fundamentals of dimming low-pressure discharge lamps is followed by a description of power and current controlled regulation, after which the 1-10V interface and Digital Addressable Lighting Interface (DALI) are described. 1.1 Characteristics of low-pressure discharge lamps Switch-on to dimming During the preheating phase the gas discharge tube is flooded with electrons and in the process the cathodes warmed up to emission temperature with a specific energy. The necessary preheating energy is determined by the physical design of the cathodes and is produced by applying a current to them for a selected preheating time. When preheating times are lower than 0.4s, ensuring homogeneous heat distribution in the cathode filaments can be problematic because of their mass. A too long preheating time, on the other hand, is annoying for the user. For that reason the preheating time should be no longer than 2s. A mismatch during preheating will shorten the lifetime of the low-pressure discharge lamp especially when the ballast is switched off and on very often. Adherence to the specified limits is checked by means of a substitute resistor RSUB for the cathode. The energy supplied during the specified preheating time is measured at this resistor. The minimum and maximum preheating energy limits are calculated using these values according to the following formulas: Application Note 6 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming - Introduction QPH,min [OS-KLTN-03 OS-KLTN-03] QPH ,min = Q + Pt _ PH QPH,max [OS-KLTN-03 OS-KLTN-03] QPH ,max = 1,75 Qvorheiz ,min If constant current or voltage preheating is used, then the currents or voltages necessary for proper preheating can be calculated using the formulas below: VPH,constant [OS-KLTN-03 OS-KLTN-03] VPH ,cons tan t = Q RSUB + P RSUB t PH I PH ,cons tan t = Q P + RSUB t PH RSUB IPH,constant [OS-KLTN-03 OS-KLTN-03] As an example, Table 2 gives the values for an OSRAM Dulux® T/E 26W lamp for calculating the preheating voltages or currents: Table 2 Preheating data for OSRAM Dulux® T/E 26W [OS-KLTN-03 OS-KLTN-03] Lamp type P [W] Q [J] RSUB [] OSRAM Dulux® T/E 26W 0,8 1,0 9 So for the lamp used here, the result when the preheating time is 1s is a minimum necessary preheating voltage (voltage preheating) of: VPH,constant-values V PH ,constan t = Q RSUB 1J 9 + P RSUB = + 0.8W 9 = 4,03V t PH 1s The gas discharge tube must not ignite during the preheating phase, so the resonant circuit must be tuned in that way that the voltage across the lamp does not exceed the maximum permissible preheating voltage (see IEC 60081 and IEC 60901). The frequency is changed during the ignition phase towards the resonant frequency. This causes the lamp voltage to rise until the gas discharge tube ignites. After successful ignition, the converter is driven by means of the working frequency. Adherence to all the limiting values specified by the lamp manufacturer must be ensured in all phases. The main operating parameters that have to be checked for a standard ballast are: · · the lamp current and lamp voltage the pin currents of the lamp's terminals Compliance with various operating parameters is required so that dimming applied to low-pressure discharge lamps will not shorten the lamps' lifetime. At maximum brightness the current flowing through the gas discharge tube is sufficient to maintain gas discharging. The gas discharge tube does not have to be additionally enriched with electrons in this mode. The function of deactivating or drastically reducing cathode heating during operation is called cut-off technology, and reduces losses in the lamp. Lighting manufacturers recommend operating new lamps for around 100 hours at maximum brightness prior to dimming so that the lifetime will not be adversely affected. Reducing the lamp current to values below 80 percent of the rated current requires the cathodes to be additionally heated to be maintained at their correct emission temperature. Minimum and maximum limiting values have to be adhered to for cathode heating in the dimming mode to maintain the lamps' specified lifetime. Excessive heating will cause emitter material in the cathode filaments to evaporate Application Note 7 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming - Introduction and blacken the glass bulb in the region of the cathodes (end blackening). If the cathodes are not heated enough emitter material will be ejected (sputtering) and the cathodes will also be prematurely destroyed. Both these instances of incorrect heating will considerably shorten the lamp's lifetime. Figure 2 shows that there is a target range within which cathode heating is optimally matched. End blac keni ng Sp utt eri ng Life 2 2 Ipin 1 + I pin 2 Target Figure 2 Cathode heating [OS-KLTN-03 OS-KLTN-03] The continuous heating current cannot, without considerable effort, be directly measured with the gas discharge tube ignited because the heating current has the lamp current superimposed on it. For design reasons these currents can differ with respect to phase, frequency, and curve shape. The variable that is critical for cathode heating is the electrically introduced heating power. The following approximation can be applied for this. [OS-KLTN-03 OS-KLTN-03] Pheating ( ) ( ) ( Pheating = Pdisch arg e + Pheating = f I 2 disch arg e , I 2 heating f I 2 disch arg e + I 2 heating f I 2 Lead 1 + I 2 Lead 2 ) The heating energy introduced can accordingly be determined by the sum of the respective cathode's squared pin currents. This makes cathode heating much easier to measure because the pin currents can be measured directly using an AC current probe. The limiting values for the heating energy as well as the optimal working point for the dimming range can be calculated using the values from Table 3. These values are specified by lamp manufacturers and are given here by way of example for an OSRAM Dulux® T/E 26W lamp: Table 3 Heating data for OSRAM Dulux® T/E 26W [OS-KLTN-03 OS-KLTN-03] Lamp ILampmin mtarget [A] [A2/A] btarget [A2] mmin [A2/A] bmin [A2] mmax [A2/A] bmax [A2] OSRAM Dulux® T/E 26W 0.030 0.175 0.570 0.175 0.145 0.210 0.171 With the lamp current Idischarge, along with these parameters and the three formulas below, the limits and target curve can be entered in a chart, what is termed the dimming characteristic: I2Lead1+I2Lead2target [OS-KLTN-03 OS-KLTN-03] I 2 Lead 1 + I 2 Lead 2 2 2 Lead1+I Lead2min t arg et [OS-KLTN-03 OS-KLTN-03] I 2 Lead1 + I 2 Lead 2 2 2 Lead1+I Lead2max min = - mmin I disch arg e + bmin max = + mmax I disch arg e + bmax [OS-KLTN-03 OS-KLTN-03] I 2 Lead 1 + I 2 Lead 2 Application Note = -mt arg et I disch arg e + bt arg et 8 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming - Introduction Figure 3 shows by way of example a dimming characteristic for an OSRAM Dulux® D/E 26W lamp. Dimming characteristic DULUX D/E 26 W 0,5 Minimum 0,45 Target value Ipin 12 + Ipin 22 [A2] 0,4 Maximum 0,35 Id ,1-pin" (without heating) 0,3 Id ,2-pin" (without heating) 0,25 0,2 0,15 0,1 0,05 0 0 0,2 0,1 0,3 300 Id [A] Figure 3 Dimming characteristic for OSRAM Dulux® D/E 26W [OS-KLTN-03 OS-KLTN-03] Reducing the lamp current to below around 220mA requires additional heating of the cathodes. In practice, however, the cathodes should be further heated earlier because the target curve is higher than the minimum limiting value. Reliable information about the lamp's lifetime can, only be provided after continuous tests because exact operation along the target curve is scarcely possible. 1.2 Overview of dimming options Dimming electronic ballasts by changing the input voltage is not possible except at considerable expense and effort. The PFC stage keeps the BUS voltage at a fixed value and compensates any fluctuations in the input voltage. For dimming by way of a change in the AC power supply voltage the PFC stage would need to be redesigned for the BUS voltage to change its value as a function of the AC power supply input voltage. The controlled BUS voltage ensures that the operating conditions for the converter are kept constant. So, lamp operation at a constant level will be ensured also in the presence of fluctuating AC power supply voltages. With the solution described here, the brightness is set by way of a change in converter frequency and a resulting change in the load circuit impedance. In that way it is possible to influence the lamp's working point. It is possible to build a control which sets the lamp current as a function of a specified setpoint value by changing the converter's frequency. Another variant is to measure the lamp's output power and use that for the actual value. There is no point in adjusting to the lamp voltage since this is highly dependent on the operating conditions and can vary widely across different lamps. The setpoint value is usually set via an external interface, what is termed the 1-10V interface for instance, or the DALI bus. Both systems will be briefly explained below following an explanation of power and current control. 1.2.1 Power control With power control, the lamp's power output is controlled. The advantage of this type of control is that the lamp's power output is adjusted to the set value immediately after ignition. Problematic is the measurement of the lamp's actual power output. In practice, therefore, the compromise route is often taken of measuring the power of the halfbridge via a shunt resistor. However, with that configuration it is not possible to distinguish between the cathode Application Note 9 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming - Introduction heating power and that consumed in the gas discharge tube. At low brightness levels the cathode heating power is far greater than the power converted into light. The cathodes' characteristics are subject to wide tolerances and change over the lamp's lifetime. Specifically in the dimming mode, this has the disadvantage that large differences in brightness can occur among different lamps. Moreover, very small lamp currents are a problem to implement for the reasons cited above. These problems can be eliminated by measuring the lamp's actual power output. That necessitates measuring the lamp burning voltage and lamp current. Multiplying these variables will result the lamp's power output. However, multiplications require many extra components or a lot of computing time and so are critical in the regulation process and more expensive to implement. That is why current regulation is often used instead. 1.2.2 Current control With current control it is only necessary to measure the lamp current. This can be done in an easy way for example a shunt resistor in the lamp circuit, independently of the cathode currents. That enables constant brightness levels to be provided even when the lamp current is low. Different lamps having the same lamp currents can be operated using the same electronic ballast. This feature makes it possible to design electronic ballasts capable of driving different lamps. These general-purpose electronic ballasts greatly reduce storage and maintenance overheads for illuminating devices. The lamp's transient response has a disadvantageous impact during current controlling. The lamp's voltage changes a certain time after ignition and so the lamp's power output can vary. This is not subsequently adjusted in the case of current control. This type of control is applied in many types of electronic ballast because it can be constructed with relatively few components. 1.2.3 1-10V interface The 1-10V interface is an interface for illuminating devices (electronic ballasts in the main) that is used to set their brightness. The market is at present still dominated by the 1-10V interface. It provides a standard for lamp manufacturers for dimming devices from different electronic ballast manufacturers. The interface provides a control current that produces a voltage drop at the interface via a potentiometer functioning as a current sink. The lamp is dimmed as a function of this voltage drop. It is also possible to inject a DC voltage level directly via a DC source in order to influence the brightness, where maximum brightness or operation at rated output power corresponds to an interface voltage of 10V. This operation is set with open interface terminals - for example. Minimum brightness is set with a shorted interface or using an interface voltage of 1V. The regulator side is electrically isolated from the electronic ballast's AC power supply. This precondition enables several electronic ballasts to be operated on different phases via the same control device. The electronic ballasts cannot be addressed individually when a 1-10V interface is used. 1.2.4 DALI (Digital Addressable Lighting Interface) The Digital Addressable Lighting Interface is a standardized digital protocol with which illuminating devices can be controlled. DALI can be regarded as a successor to the 1-10V interface. It is a system that allows illuminating devices to be directly accessed individually via addresses. Like the 1-10V interface, the DALI interface is also electrically isolated from the AC power supply. As the line can be up to 300m in length, there are nearly no restrictions installing the system in large buildings. Moreover, it is possible to connect up to 64 illuminating devices together. DALI enables devices to be switched on and off directly via the BUS system by means of a control signal. This means it is not necessary to interrupt the AC power supply and the additional saving of an installation of a switch for disconnecting the operating voltage can reduce costs. [DALI-AG-03 DALI-AG-03] Application Note 10 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 2 Dimming with the ICB2FL02G ICB2FL02G Figure 4 shows the circuit diagram expanded to include the dimming function using the ICB2FL02G ICB2FL02G FL-Controller. An OSRAM Dulux® T/E 26W is used as the lamp. Figure 4 Dimmable Demoboard: Circuit diagram with dimming function To change the working frequency during operation in this circuit it is necessary to influence the resistance at the RFRUN Pin. A voltage of 2.5V is provided at that pin from the IC. The current drawn from the pin is measured and the working frequency is varied as a function thereof. A higher current results in a higher working frequency. The lamp current is reduced due to the change in load-circuit impedance. Continuous cathode heating is necessary to ensure that a sufficient cathode temperature is also attained in the dimming mode. For that, the heating circuit (consisting of L21 - C21 and L22 - C22) needs to be matched to the frequency curve. This matching will be discussed in this first section, followed by a description of the solution using current controlled regulation with the 1-10V interface for setting the brightness. 2.1 Matching the heating circuit for cathode heating With non-dimmable electronic ballasts, the function of the heating circuit for the cathodes is to maximize cathode heating during the preheating phase and drastically reduce it at the working frequency. Reduced losses in the lamp and increased efficiency in the run mode are the positive results. This is an expedient measure because at maximum brightness the lamp current suffices to maintain the cathodes at their emission temperature. The difficulty in the case of dimmable electronic ballasts is that the cathodes require additional heating when the lamp current is reduced. This is necessary because heating by means of the lamp current does not suffice to maintain gas discharging. This capability can be provided by matching the heating circuit to the respective frequency range. A brief overview of different matching is given to illustrate the voltage curve at the cathode over the frequency range. The resonant frequencies of these combinations are around 95kHz. Application Note 11 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G For this electronic ballast in a non-dimmable variant a combination using 127µH and 22nF is suitable. This combination reduces cathode heating drastically during operation. This feature is called cut off technology. Figure 5 shows simulated voltage curves over the cathodes filament for different heating circuit matching. 8 7 6 Filament voltage [V] 5 4 3 2 1 0 30 40 50 60 70 80 90 100 fRUN [kHz] 28H - 100nF Figure 5 41H - 68nF 60H - 47nF 85H - 33nF 127H - 22nF Heating circuit variants (simulation) A reduction in cathode heating at the working frequency is achieved via the frequency-dependent change in impedance in the heating circuit. The preheating frequency is set in accordance with the heating circuit's resonant frequency to achieve maximum cathode heating at that working point. By evaluating the dimming characteristic a check is carried out to determine if the cathode heating is sufficient in the case of dimmable electronic ballasts. The measurements performed for different heating circuits results in a combination of a 68µH inductor and 47nF capacitor as a good solution. The resonant frequency of that combination is: fRes f Re s = 1 2 L C = 1 2 68µH 47nF = 89kHz This resonant frequency differs from that of the original heating circuit; the preheating frequency needs to be set to this value. The following formula for determining the preheating resistance RFPH is given in the ballast controller datasheet: RRFPH RRFPH = RRFRUN 12 k = 10.56 k 11k = 89 kHz 12 k fPH RRFRUN -1 -1 5 10 8 Hz 5 10 8 Hz With a resistance of 11k, the preheating frequency is very close to the resonant frequency of the heating circuit. This matching is retained for the following studies. Application Note 12 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 2.2 Operating principle The aim of this concept is to build a regulator and to control the lamp current via a frequency change. For that it is necessary to measure and evaluate the lamp current. This is done using a combination of shunt resistor and diode. The setpoint value is set via a 1-10V interface and the control function is assumed by an operational amplifier (OP) working as a PI-Regulator. The OP output operates on a transistor that influences the resistance at the RFRUN Pin and in that way changes the working frequency. A new lamp current is set as a result. to Lamp (GND-side) 2 to cathode of D8 1 3 1-10V input Figure 6 to RFRUN Pin Dimming circuit Figure 6 shows the additional circuitry required for expanding the original circuit into a dimmable ballast. The supply voltage for the operational amplifier is decoupled via D89 on the charge pump and smoothed at C86. 2.2.1 1-10V interface The setpoint value for the brightness is set via the 1-10V interface. The red arrows in Figure 6 indicate the respective measuring point for the two oscillograms shown further below and are labeled with the number of the respective channel. Table 4 gives an overview of the individual components' functions. Table 4 Overview of the individual components' functions Reference Function R82 Protects against polarity reversal, overvoltage and inadvertent AC power supply connection at the interface L3 1:1 transformer D83 Protects C80 against overvoltage and polarity reversal of the interface in conjunction with R82 C80 Compensates disruptions on the interface voltage and smoothes the voltage during operation with an electronic potentiometer D84 Blocks the interface voltage for the interface side of the transformer so that no DC will flow through it. D85 Limit the maximum level on the transformer's interface side D86 R83 Limits the current for supplying the transformer R84 Attenuates the transformer Application Note 13 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G Table 4 Overview of the individual components' functions Reference Function R85 Decouple the positive voltage component over the transformer and perform smoothing D87 C81 R86 Matches the voltage level at C81 to the desired value R87 Divide the voltage to set VR86 to the desired range R88 C82 Delays changes in the setpoint value and prevents very fast changes. This capacitor can be increased in size if necessary to minimize flickering over the dimming range. Described here is the mode of operation of the interface circuit when setting it via a DC level. The circuit section on the transformer's left-hand side is referred to the interface side and the section on its right-hand side is referred to the circuit side. The voltage injected at the interface can be measured at C80. If an AC voltage corresponding in amplitude at least to the forward voltage + interface voltage is then made available on the 1:1 transformer's circuit side, a current will flow on the interface side. The forward voltage of D84 is added to the applied voltage (measuring point 1, Figure 7, channel 1 red). This voltage amplitude is transformed to the circuit side and smoothed via R85 and D87 at C81 (measuring point 3, Figure 7, channel 3 green). Vtransformer Interface side Clock (charge pump) VC81 Interface voltage = 10 VRMS VC81 = 7,6 VRMS ILamp = 300 mARMS Figure 7 Interface voltage = 1,7 VRMS VC81 = 2,8 VRMS ILamp = 20 mARMS Oscillograms, interface The voltage for driving the transformer is decoupled at the electronic ballast's charge pump (measuring point 2, Figure 7, channel 2 blue). This is done at the cathode of D8 (Figure 4). The minimum amplitude is determined by the forward voltage of D8, while the maximum amplitude is limited by D9 and D7 (Figure 4) to approximately 16V. This voltage is therefore very suitable for driving the interface transformer without the use of additional components. The change in frequency in the dimming range does not adversely affect the operation of the interface. The amplitude is set to the desired range for setpoint value setting via R87 and R88. C82 ensures a soft transition between different dimming settings. This capacitor can be further increased in size if necessary to achieve a greater time constant for changes in brightness. If an electronic potentiometer is used for setting the setpoint value, then the basic function will - as described in the preceding section - be retained. However, no DC voltage for the basic level will be injected via C80 in this operating mode. This voltage drop is produced by the electronic potentiometer via the voltage pulses transmitted from the circuit side. In this operating mode, C80 has the additional function of voltage smoothing. Application Note 14 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 2.2.2 Lamp current sensing for the actual value The lamp current is determined via a shunt resistor combined with a diode. The negative half-wave is routed directly to ground via D82. The positive half-wave, by contrast, is decoupled via D80 for measuring the actual value and generates a voltage drop at R80, R81 and D81. At high brightness levels or lamp currents the voltage drop is generated via R80 and D81. R81 has no effect in this mode because diode D81 is parallel to it and limits the voltage to its own threshold voltage. The maximum brightness can be set with R80. The minimum brightness is set with R81. In the case of small currents the voltage drop at R81 is not sufficient to exceed the threshold voltage of D81. For that reason the diode can be ignored when considering the minimum brightness. At maximum dimming the voltage drop is consequently generated via R80 and R81. So this circuit allows relatively independent setting of the minimum and maximum limiting values for controlling brightness. 2.2.3 Regulating circuit A PI-Regulator is used for the controlling function. The setpoint value is passed by the 1-10V interface to the inverting OP (IC2) input via R89. The actual value is supplied to the OP via the low pass filter that consists of R90 and C83 and smoothes the voltage. R92 serves to limit the current, while Z-Diode D88 limits the voltage at the base of transistor Q8 so that the IC's RFRUN Pin will not be damaged in the event of large overswings. The minimum working frequency is set with R21 (in the non-dimmable variant, this resistor sets the working frequency to a fixed value). Via driving of Q8 the RFRUN Pin can be additionally loaded via resistor R93 and the working frequency thereby increased. The control loop functions as follows: The actual value is proportional to the lamp current. If the current increases, the voltage will also increase at the non inverting OP input. The OP output will become more positive because of this voltage rise and the conductivity of transistor Q8 will increase. Loading of the RFRUN Pin will then increase the converter frequency. The lamp current decreases as the result of the higher working frequency. This compensates the previous deviation of the lamp current. So negative feedback occurs and the control loop is stable. For calculating R93, which establishes the controller's possible correcting range, the following parameters were taken as the basis: The RFRUN Pin's voltage source supplies 2.5V. Using the formula for calculating the resistance at different working frequencies, the following values are obtained: RRFRUN_40kHz RRFRUN _ 40 kHz = 5 108 Hz selected = 12,5k 12k := R21 40kHz RRFRUN_80kHz RRFRUN _ 80 kHz = 5 108 Hz = 6,3k 80kHz All working points between these frequencies can be set via driving of Q8 with R93=6.8k parallel to R21. The operation of the regulator at the time of ignition is shown in Figure 8 with the aid of an oscillogram. Application Note 15 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G VLamp ILamp VR93 VC83 Figure 8 Regulator operation during ignition of the lamp The oscillogram has two parts: The top part is set to a resolution of 100ms/Div, the bottom part is zoomed in to a resolution of 2ms/Div for observing the regulator's behaviour at the instant of ignition more closely. Application Note 16 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 2.2.4 Dimming characteristic Figure 9 shows the dimming characteristic achieved using the solution described here. Heating circuit matching for cathode heating is 47nF and 68µH. 0,220 0,200 0,180 0,160 I²LH + I²LL [A2] 0,140 0,120 0,100 0,080 0,060 0,040 0,020 0,000 0,0 30,0 60,0 90,0 120,0 150,0 180,0 210,0 240,0 270,0 300,0 ILamp [mA] (I²LH + I²LL) cath.1 Figure 9 (I²LH + I²LL) cath.2 (I²LH + I²LL) target (I²LH + I²LL) min (I²LH + I²LL) max Dimming characteristic It can be seen from the dimming characteristic that over a dimming range of about 10 to 100 percent, cathode heating is within the required limits. A further reduction in the lamp current to around five percent of the rated lamp current will result in cathode heating exceeding the required limiting values. The cathode heating circuit has to be modified by the components itself or by decoupling the windings on the swinging choke. In this way correct dimming operation down to one percent of the lamp's rated current can be implemented. There are no limitations of the IC to realise dimming ballasts with much lower brightness levels. Application Note 17 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 350,0 160,0 140,0 300,0 120,0 100,0 200,0 80,0 150,0 Lamp current [mA] VLamp [V] and fInverter [kHz] 250,0 60,0 100,0 40,0 50,0 20,0 0,0 0,0 0,00 1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00 9,00 10,00 Interface voltage [V] [li] Lamp voltage Figure 10 [li] Inverter frequency [re] Lampenstrom Interface: V, I, f characteristic Figure 10 shows the correlation between lamp voltage, working frequency and lamp current as a function of the interface voltage. The lamp current slope here reduces in the direction of lower interface voltages. This accords with the human eye's sensitivity to brightness. A change in lamp current by, for instance, 10% is perceived far more intensely at minimum than at maximum brightness. Application Note 18 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 2.2.5 Notes Figure 11 54 Wdg. SWD 1 Wdg./Kath. 54 Wdg. SWD 2 Wdg./Kath. 54 Wdg. SWD 1 Wdg./Kath. 1 Wdg./Kath. 54 Wdg. SWD 54 Wdg. SWD 54 Wdg. SWD 5 Wdg./Kath. 54 Wdg. SWD 54 Wdg. SWD 5 Wdg. Kath.2 54 Wdg. SWD 54 Wdg. SWD 5 Wdg. Kath.1 54 Wdg. SWD 54 Wdg. SWD Figure 11 (left) shows the winding scheme of the swinging choke, with the winding distribution applied in this circuit for the heating windings. The decoupling windings are in each case located in the swinging choke's left hand and right hand winding chamber. Swinging choke with chambers and windings The best and most equal cathode heating will be attained if the decoupling windings are wound in the same chamber (Figure 11, center). In respect to mass production and in the case of devices containing many lamps, this is unfortunately rarely possible to put into practice since the available winding space is limited. Cathode heating will also be relatively equal if the decoupling windings for both cathodes are wound diagonally from one side to the other across the entire winding body. This winding scheme is shown on the right in Figure 11. This scheme can also be used when there are several lamps because the turns can be distributed evenly across all winding chambers. With this variant, however, it is especially important to consider the dielectric strength of the protecting lacquer because the ignition voltage is applied during the ignition phase between the cathodes and that can cause voltage breakdown between the windings. The position of the windings is also relevant to the output voltage level (heating voltage). The cathode heating voltage will be different when both windings are wound in one of the inner chambers. It will be somewhat higher if distribution diagonally from one side to the other. So there are numerous parameters for influencing cathode heating. During adjustment of the overload detection it needs to be considered that the lamp voltage rises in the dimming mode. This characteristic can cause the overload detection to trigger even though no fault has occurred. Overvoltage of this kind in the dimming mode could conceivably be compensated by means of a frequencydependent overload detection circuit. Figure 12 shows, for comparison, two dimming curves with the same number of windings on the swinging choke. However, the heating windings are distributed differently on the winding body for the two measurements. The top diagram shows the results when the heating windings of both cathodes are wound absolute symmetrical to the air gap of the core. The bottom diagram shows the curve when the windings are distributed not exactly symmetrical to the air gap of the core. Application Note 19 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G 0,220 0,200 0,180 0,160 I²LH + I²LL [A2] 0,140 0,120 0,100 0,080 0,060 0,040 0,020 0,000 0,0 30,0 60,0 90,0 120,0 150,0 180,0 210,0 240,0 270,0 300,0 ILamp [mA] (I²LH + I²LL) cath.1 (I²LH + I²LL) cath.2 (I²LH + I²LL) target (I²LH + I²LL) min (I²LH + I²LL) max 0,220 0,200 0,180 0,160 I²LH + I²LL [A2] 0,140 0,120 0,100 0,080 0,060 0,040 0,020 0,000 0,0 30,0 60,0 90,0 120,0 150,0 180,0 210,0 240,0 270,0 300,0 ILamp [mA] (I²LH + I²LL) cath.1 Figure 12 (I²LH + I²LL) cath.2 (I²LH + I²LL) target (I²LH + I²LL) min (I²LH + I²LL) max Cathode heating: Chamber distribution Application Note 20 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Dimming with the ICB2FL02G ICB2FL02G As it can be seen from the dimming curves, even at low-brightness levels, differently distributed windings will already cause cathode heating to exceed the limiting values. To avoid subsequent re-matching, it should be considered that the winding distribution on the swinging choke can be implemented in volume production. EOL1 detection must be matched so that the increased lamp voltage in the dimming mode will not result in detection of a failure. Matching at the RES Pin for lamp detection needs to be adjusted because shunt resistors and diodes are inserted in the ground path for current sensing. The temperature dependency of current sensing (diodes and resistors in the lamp's ground branch) influences the lamp current. Application Note 21 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Layout, schematic and BOM 3 Layout, schematic and BOM In this chapter the documentation for the demo board is included. Figure 13 Demoboard PCB complete Figure 14 Demoboard mounting top Figure 15 Demoboard mounting bottom Figure 16 Demoboard copper bottom Application Note 22 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Layout, schematic and BOM Figure 17 Extended Schematic - Dimming with ICB2FL02G ICB2FL02G with Auto Dim Figure 17 shows an extended Schematic with an Auto-Dim functionality. In this mode, activation via a switch JP1, the ballast automatically dims between 5% and 100% up and down. This functionality can be additional assembled on the Demoboard for demonstration purposes. The BOM (Figure 18) shows which components are necessary for realisation this functionality. An detailed explanation of this additional circuit is not given in this Application Note. Application Note 23 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Layout, schematic and BOM BOM: Demo-Dim 1x26W TC-TEL - VM - 180VAC 180VAC to 270VAC 270VAC - ICB2FL02G ICB2FL02G ICB2FL02G ICB2FL02G Input voltage = 180VAC 180VAC to 270VAC 270VAC VBUS = 410 VRMS Package F1 Fuse 1A fast Fuse Holder K1/1 AC Input K1/2 AC Input K1/3 PE K2/1 not connected K2/2 High Side Filament K2/3 High Side Filament K3/1 Low Side Filament K3/2 Low Side Filament K3/3 not connected K8/1 Dimming 1-10V (+) K8/2 Dimming 1-10V (-) K8/3 not connected IC1 ICB2FL02G ICB2FL02G Q1 SPD03N60C3 SPD03N60C3 Q2 SPD03N60C3 SPD03N60C3 Q3 SPD03N60C3 SPD03N60C3 D1.4 S1M D5 MURS160T3 MURS160T3 D6 BYG26J BYG26J D7 BYG22D BYG22D D8 BYG22D BYG22D D9 BZX284C16 BZX284C16 L101 2x68mH/0.6A L1 1.58mH (PFC) L2 2.15mH L21 68H/800mA L22 68H/800mA C1 220nF/305V/X2 C2 33nF/630V/MKT C3 3,3nF/Y2 C4 220nF/X2/305V C10 10F/450V 10F/450V C11 2,2nF/50V C12 100nF/50V C13 1F/25V 1F/25V C14 100nF/50V C15 22nF/630V/MKT C16 1nF/630V/MKT C17 100nF/630V C19 22nF/50V C20 6,8nF/1600V/MKP C21 47nF/400V/MKT C22 47nF/400V/MKT C40 470nF/25V R1 390k R2 390k DR12 110k R11 470k R12 470k R13 33k R14 820k R15 820k R16 22 R18 1 R19 not assembled R20 10k R21 12k (41,6kHz!) R22 11k (87,1kHz!) R23 10k (1000ms!) R24 not assembled R25 0.56 R26 22 R27 22 R30 33 R34 150k R35 150k R36 47k R36A 0 LVS2 (pin14) is connected to GND R41 27k R42 150k R43 150k R44 150k R45 6,8k R61 0 J1 0 Figure 18 Wickmann Typ 370 B-Nr: 250-203 B-Nr: 250-203 B-Nr: 250-203 B-Nr: 250-203 Infineon Infineon Infineon Infineon Fairchild ON Semi Philips Philips Philips Philips Epcos Epcos Epcos Epcos Epcos Epcos Epcos Epcos Epcos Epcos B82732F2601B001 B82732F2601B001 B78326P7373A005 B78326P7373A005 T5639-51-01 T5639-51-01 B82144B1683J B82144B1683J B82144B1683J B82144B1683J B32922C3224M000 B32922C3224M000 B32521N8333K000 B32521N8333K000 B32021A3332K000 B32021A3332K000 B32922C3224M000 B32922C3224M000 B43888C5106M000 B43888C5106M000 Epcos Epcos Epcos Epcos B32529C8102K000 B32529C8102K000 B32612A6104K008 B32612A6104K008 Epcos Epcos Epcos B32520-C6473K B32520-C6473K B32520-C6473K B32520-C6473K (1000V/1A/2s) (600V/1A/75ns) (600V/1A/30ns) (200V/1A/25ns) (200V/1A/25ns) SO-20 SO-20 D-Pack D-Pack D-Pack DO-214AC DO-214AC SMB SOD124 DO214 DO214 DO214 DO214 SOD110 EFD25/13/9 EFD25/13/9 EFD25/13/9 EFD25/13/9 RM5 RM5 RM15 RM10 RM10 RM15 single ended .0805 .0805 .1206 .0805 RM10 RM5 RM15 .0805 RM15 RM7,5 RM7,5 .0805 .1206 .1206 .1206 .1206 .1206 .1206 .1206 .1206 .0805 .1206 .1206 .0805 .0805 .0805 .0805 .1206 .1206 .0805 .0805 .1206 .1206 .1206 .1206 .1206 Package Components for Manual-Dimming IC2 LM258D LM258D JP1* connect Pin 2 and 3 (0 ) Q8 BC817 BC817 D80 BYG22D BYG22D D81 BYG22D BYG22D D82 BYG22D BYG22D D83 Z-Diode 11V D84 LL4148 LL4148 D85 LL4148 LL4148 D86 Z-Diode 10V D87 LL4148 LL4148 D88 Z-Diode 2,7V D89 BYG22D BYG22D L3 2x27mH 1:1 C80 2,2F C81 100nF C82 4,7F C83 10nF C84 82pF C85 100nF C86 100nF C87 optional (1nF) R80 3,3 R801 3,3 R81 27 R802 not assembled R82 PTC 884 (B59884C B59884C) R83 2,2k R84 15k R85 1,5k R86 120k R87 150k R88 12k R89 3,3k R90 3,3k * R91 3,3k R92 10k R93 6,8k SO-8 1206 SOT23 DO214 DO214 DO214 DO214 DO214 DO214 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 DO214 DO214 .1206 .0805 .1206 .0805 .0805 .0805 .0805 .0805 .1206 .1206 .1206 .1206 .0805 .0805 .0805 .0805 .0805 .0805 .0805 .0805 .0805 .0805 .0805 *some older designs my have 10k mounted, in this case please replace the 10k resistor with 3,3k . Optional for AUX-Pin Damping D10 BYG26J BYG26J Q4 BCP55 BCP55 R4 300 R402 300 R403 300 SOD124 SOT-223 .1206 .1206 .1206 Optional for Auto-Dimming JP1 switch 3 pol. D100 LL4148 LL4148 D101 LL4148 LL4148 D102* Z-Diode 11V D103 optional (BAS40-4 BAS40-4) C100 4,7F R100 100k R101 33k R102 390k R103 18k R104 1M R105 10M MM1206 MM1206 MM1206 MM1206 MM1206 MM1206 SOT23 .1206 .0805 .0805 .0805 .0805 .0805 .0805 * For Auto-Dimming functionality a 3 pol. Switch is required (see below) * The polarity must be pole changed in respect to the Layout printing. .1206 .1206 .1206 .1206 .1206 .0805 .0805 BOM of the Demoboard Application Note 24 Rev. 1.0, 2009-08-07 Application Note - ICB2FL02G ICB2FL02G Bibliographic references 4 Bibliographic references Table 5 Bibliographic references [DALI-AG-03 DALI-AG-03] DALI AG, http://www.dali-ag.org, May 2003 [OS-KLTN-03 OS-KLTN-03] Osram, Osram Compact Fluorescent technical guide, January 1996 Application Note 25 Rev. 1.0, 2009-08-07 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. Dazu gehört eine bestimmte Geisteshaltung unserer Mitarbeiter. 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