Application Note AN-1039 IR2159: Dimming Dual Lamp Parallel Configuration with Balance Transformer By T. Ribarich, R. Marenche 1. Basic Circuit Considerations........................................................... 1 2. Figure 1: Dual Lamp Parallel Configuration.................................... 2 3. Schematic....................................................................................... 3 4. Bill of Materials ............................................................................... 4 The IR2159 dimming ballast control IC can be used with some modifications to the ballast output stage, to allow both lamps to be dimmed while maintaining equal brightness in both lamps. Through externally programmable components, the IR2159 offers flexibility of various features such as preheat time and current and minimum and maximum brightness settings. Comprehensive protection features protect the circuit against conditions such as lamp strike failures, filament failures, low DC bus, thermal overload, or lamp failure during normal operation. This circuit switches off both lamps when one is taken out, and automatically restarts when both lamps are in place. APPLICATION NOTE AN1039 International Rectifier •233 Kansas Street El Segundo CA 90245 USA IR2159: Dimming Dual Lamp Parallel Configuration with Balance Transformer By T. Ribarich, R. Marenche TOPICS COVERED Basic Circuit Considerations Schematic Diagrams Bill of Materials A popular and economical configuration for dimmable fluorescent ballasts is for driving two lamps in parallel. The IR2159 dimming ballast control IC can be used with some modifications to the ballast output stage, to allow both lamps to be dimmed while maintaining equal brightness in both lamps. Through externally programmable components, the IR2159 offers flexibility of various features such as preheat time and current and minimum and maximum brightness settings. Comprehensive protection features protect the circuit against conditions such as lamp strike failures, filament failures, low DC bus, thermal overload, or lamp failure during normal operation. This circuit switches off both lamps when one is taken out, and automatically restarts when both lamps are in place. 1. BASIC CIRCUIT CONSIDERATIONS The output stage has been modified for two lamps in parallel (Figure 1). The lamps have been placed outside the under-damped resonant circuit loop which consists of L3 and C15. The filament heating during preheat and dimming is achieved using voltage-mode filament heating with secondary windings off of the resonant inductor (L3A, L3B, L3C, L3D). A balance transformer (L4) provides equal currents through both lamps such that equal brightness is obtained during dimming. The DC blocking capacitor, C16, is also placed outside the under-damped resonant circuit loop such that it does not influence the natural resonance frequency of L3 and C15. During lamp removal, both lower filament signals are OR-ed into the shutdown pin, SD, through resistors R16 and R18. 1 AC Rectified Line R20 L3 L4 (+) C16 R11 L3A L3B (4T) (4T) RVDC CVDC C18 C17 R12 R13 1 VDC HO 16 2 VCO VS 15 3 CPH VB 14 M2 C15 CVCO C14 C9 5 MAX 6 7 D4 VCC 13 COM 12 MIN LO 11 FMIN CS 10 RMAX R21 R22 C10 D5 C11 R14 CMIN R19 DIM IR2159 4 C13 M3 R17 CPH R15 D6 L3C L3D (4T) (4T) R16 RFMIN RMIN 8 IPH SD 9 R18 RIPH CCS C12 C19 RCS D7 (-) Figure 1, Dual lamp parallel configuration. 2 C20 X1E (-) (+) X1D C1 RV1 C2 BR1 C3 R3 R2 R1 R6 C4 R5 R4 C5 R7 4 3 2 1 5 6 7 C6 C7 R9 R10 M1 C8 D2 CDIM D3 CMIN RMAX CPH CVCO CVDC RVDC R11 RFMIN MAX MIN FMIN IPH 5 6 7 8 RIPH DIM CPH VCO VDC 4 3 2 1 14 VB SD CS LO CCS 9 10 11 COM 12 13 15 VS VCC 16 HO C10 D4 R21 C9 C12 R13 Note: Thick traces represent high-frequency, high-current paths. Lead lengths should be minimized to avoid high-frequency noise problems MC34262 8 D1 R8 IR2159 0.5 to 5VDC DIM INPUT GND N L L1 RDIM L2 RMIN 3 R15 R14 M3 RCS R16 C11 R22 R12 R17 R18 M2 D5 C13 R19 D6 C14 D7 C15 L3 C19 (4T) C20 (4T) L3D (4T) L3C L3B C17 L3A L4 C18 (4T) C16 R20 Schematic Bill Of Materials Lamp type: T8/36W X 2 Line Input Voltage: 180..255 VAC/50..60 Hz Note: Different lamp types require different frequency programming components. Item # 1 Qt 1y International Rectifier DF10S 2 1 Roederstein WY0222MCMBF0K Capacitor, 2.2nF 275 VAC Y Cap C1 3 1 Roederstein F1772433-2200 Capacitor, 0.33uF 275 VAC C2 4 1 Wima MKP10 Capacitor, 0.1uF 400 VDC C3 5 3 Panasonic ECU-V1H103KBM Capacitor, 0.01uF SMT 1206 C4, CVCO, CDIM 6 2 Panasonic ECJ-3YB1E474K Capacitor, 0.47uF SMT 1206 C5,C6 7 1 Panasonic EEU-FC1H2R2 Capacitor, 2.2uF 50VDC 105C C7 8 1 Panasonic EEU-EB2V100 Capacitor, 10uF 350VDC 105C C8 Manufacturer Part Number Description Bridge Rectifier, 1A 1000V Reference BR1 9 4 Panasonic ECU-V1H104KBM Capacitor, 0.1uF SMT 1206 C9,C10,C12, CMIN 10 1 Panasonic EEU-FC1H4R7 Capacitor, 4.7uF 50VDC 105C C11 11 2 Vitramon 1812A102KXE Capacitor, 1nF 1KV SMT 1812 C13,C14 12 1 Wima MKP10 Capacitor, 6.8 nF,1600V C15 13 1 Panasonic ECQ-E4224KZ Capacitor, 0.22uF, 400V C16 14 4 Panasonic ECU-S1H474KBB Capacitor, 0.47uF, 50V C17, C18, C19, C20 15 2 Panasonic ECJ-3VB1E334 Capacitor, 0.33uF, SMT 1206 CVDC,CCPH 16 1 Panasonic ECU-V1H471KBM Capacitor, 470pF SMT 1206 CCS 17 4 Diodes LL4148DICT-ND Diode, 1N4148 SMT DL35 D1, D3, D5, D6 18 2 International Rectifier 10BF60 Diode, SMT SMB D2, D4 19 1 Diodes MMSZ4702T1 Diode, Zener 20V SMT DL35 D7 20 1 Motorola MC34262 IC, Power Factor Controller IC1 21 1 International Rectifier IR2159 IC, Ballast Driver IC2 22 1 Panasonic ELF-15N007A EMI Inductor, 1X10mH 0.7Apk L1 23 1 RGA RGA-EF25 PFC Inductor, 2.0mH 2.0Apk L2 24 1 L3, L3A,L3B, L3C, L3D 25 1 Panasonic ELF-15N008A Inductor, 1.0mH, 2.0Apk with 4 secondary windings of 4 turns EMI Inductor, 1X6.8mH 0.8Apk 26 3 International Rectifier IRF840 Transistor, MOSFET M1, M2, M3 27 2 Panasonic ERJ-8GEYJ680K Resistor, 680K ohm SMT 1206 R1, R2 28 1 Panasonic ERJ-8GEYJ7.5K Resistor, 7.5K ohm SMT 1206 R3 29 2 Panasonic ERJ-8GEYJ820K Resistor, 820K ohm SMT 1206 R4, R5 30 2 Panasonic ERJ-8GEYJ10K Resistor, 10K ohm SMT 1206 R6, RDIM 31 2 Panasonic ERJ-8GEYJ100K Resistor, 100K ohm SMT 1206 R7,R20 32 1 Panasonic ERJ-8GEYJ22K Resistor, 22K ohm SMT 1206 R8 33 3 Panasonic ERJ-8GEYJ22 Resistor, 22 ohm SMT 1206 R9, R13, R14 34 1 Dale CW-1/2 Resistor, 0.8 ohm ½ watt R10 35 1 Yageo 1.0MQBK-ND Resistor, 1.0megohm ¼ watt R11 36 1 Yageo 470KQBK-ND Resistor, 470Kohm ¼ watt R12 37 1 Panasonic ERJ-8GEYJ1K Resistor, 1K ohm SMT 1206 R15 38 2 Yageo 330KQBK-ND Resistor, 330K ohm ¼ watt R16,R18 39 2 Yageo 1.0MQBK-ND Resistor, 1.0M ohm ¼ watt R17,R19 40 1 Dale CW-1/2 Resistor, 0.75 ohm ½ watt RCS 41 1 Panasonic ERJ-8GEYJ19K Resistor, 19K ohm SMT 1206 RMAX 42 1 Panasonic ERJ-8ENF24.9K Resistor, 24.9K ohm SMT 1206 RMIN 43 1 Panasonic ERJ-8GEYJ30K Resistor, 30K ohm SMT 1206 RFMIN 44 1 Panasonic ERJ-8GEYJ12K Resistor, 12K ohm SMT 1206 RIPH 45 1 Panasonic ERZ-V05D471 Transient Suppressor RV1 46 2 Panasonic ERJ-8GEYJ10 Resistor, 10 ohm SMT 1206 R21, R22 Total 71 4 L4A, L4B