HV832DB1 HV832DB1 Dual EL Lamp Driver Introduction Specifications The Supertex HV832DB1 demo board contains all necessary circuitry to demonstrate the features of the HV832 dual EL lamp driver. Input Voltage 3.0V to 4.2V Supply Current 40mA Max. Simply connect it to a power supply and a lamp as shown below. For additional assistance in designing EL driver circuits, please refer to application notes AN-H33 (effect of external components on performance of Supertex EL drivers), application note ANH44 (HV832 application circuits), and AN-H43 (EL lamp driver circuits to reduce lamp audible noise). Lamp Size Range Up to 2.7in2 Lamp Frequency Converter Frequency 417Hz 53.4KHz Board Layout and Connections Re CDD VDD EL1 Com EL2 Com Ce Cs HV832 Diode LX EN-SW VIN CIN GND Demo Board Connections: VIN Inductor Supply Control lamp selection/Enable Input (EN-SW) Supplies the high voltage power converter. Connect to positive terminal of a power supply. Various modes of the device are selected via the control pin/ENSW. Each logic pulse applied to the control pin/EN-SW will cause the device to change to the next mode. The sequence for the modes is: 1) EL1 on, 2) EL2 on, 3) both EL1 and EL2 on, and 4) device shuts down. This input may be connected to a mechanical switch, or to a logic circuit output that has a source impedance of less than 20KΩ. GND Circuit Ground Connect to VDD and VIN negative terminals. Supply bypass capacitor for both VDD and VIN are provided on the demo board. External supply bypass capacitors are not necessary. EL1 and EL2 Lamp Connections Connects to lamps 1 and 2. Polarity is irrelevant. VDD IC Supply Com Lamp Connections Supplies the HV832 EL driver IC. The supplied circuit is optimized for 3.0 to 4.2 volt operations. Connect to positive terminal of a power supply. Connects to the other side of lamps 1 and 2. Polarity is irrelevant. 12/14/01 Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the Supertex website: http://www.supertex.com. For complete liability information on all Supertex products, refer to the most current databook or to the Legal/Disclaimer page on the Supertex website. 1 HV832DB1 HV832DB1 Schematic EN-SW 10KΩ Ce** 10nF EL Lamp 1 Re** + VDD 0.1µF - 1 EL1 EL2 8 2 VDD Com 7 EL Lamp 2 3 Control CS 6 4 GND LX 5 1N914* HV832MG 390µH + 3.3nF 100V VIN 4.7µF - Lx = 390µH MuRata (LQH32CN391K21) * Any (equivalent or better)> 90V, fast reverse recovery diode ** Re and Ce are used to prevent change in lamp selection due to use of mechanical switch which can have contact bounce. Typical Performance The specific external components used in the above circuit are LX=390µH Murata (LQH32CN391K21), Cs= 3.3nF 100V NPO. The following was observed when driving a 0.93in2 Green lamp. VDD(V) VIN(V) 3.3 3.3 3.0 3.0 3.2 4.2 Lamp Selection IIN(mA) VCS(V) Lamp 1 or 2 20.9 Both lamps Brightness fEL(Hz) ft-lm cd/ m2 80.7 11.75 40.2 31.1 73.0 10.64 36.4 Lamp 1 or 2 21.9 78.4 11.34 38.8 Both lamps 32.0 70.1 9.82 33.6 Lamp 1 or 2 21.3 79.8 11.64 39.8 Both lamps 31.4 72.3 10.29 35.2 Lamp 1 or 2 19.3 85.2 12.43 42.5 Both lamps 28.3 81.0 11.58 39.6 417 The following was observed when driving EL1=1.3in2 and EL2=0.93in2 Green lamps. VDD(V) 3.3 VIN(V) 3.3 Lamp Selection IIN(mA) VCS(V) EL1 23.8 81.3 EL2 20.9 80.7 Both lamps 34.2 71.7 Brightness fEL(Hz) 417 ft-lm cd/ m2 10.79 36.9 11.75 40.2 9.59 32.8 The above circuit may need to be optimized further based on specification of the lamp used. 12/13/01rev.4 ©2001 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited. 2 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 744-0100 • FAX: (408) 222-4895 www.supertex.com