1 HV832DB1 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 liabi lity 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 c hange 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 curre nt databook or to the legal/disclaimer page on the supertex website. HV832DB1 dual el lamp driver introduction the supertex HV832DB1 demo board contains all necessary circuitry to demonstrate the features of the hv832 dual el lamp driver. 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 an- h44 (hv832 application circuits), and an-h43 (el lamp driver circuits to reduce lamp audible noise). specifications input voltage 3.0v to 4.2v supply current 40ma max. lamp size range up to 2.7in 2 lamp frequency 417hz converter frequency 53.4khz demo board connections: control lamp selection/enable input (en-sw) v arious modes of the device are selected via the control pin/en- sw. 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 20k ? . v dd ic supply 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. v in inductor supply supplies the high voltage power converter. connect to positive terminal of a power supply. gnd circuit ground connect to v dd and v in negative terminals. supply bypass capacitor for both v dd and v in 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. com lamp connections connects to the other side of lamps 1 and 2. polarity is irrelevant. board layout and connections gnd hv832 en-sw com com re el1 el2 v in v dd c dd ce diode cs c in lx
2 HV832DB1 1235 bordeaux drive, sunnyvale, ca 94089 tel: (408) 744-0100 ?fax: (408) 222-4895 www.supertex.com 12/13/01rev.4 ?001 supertex inc. all rights reserved. unauthorized use or reproduction prohibited. t ypical performance the specific external components used in the above circuit are l x =390 h murata (lqh32cn391k21), cs= 3.3nf 100v npo. the following was observed when driving a 0.93in 2 green lamp. the following was observed when driving el1=1.3in 2 and el2=0.93in 2 green lamps. the above circuit may need to be optimized further based on specification of the lamp used. v d d ) v (v n i ) v ( p m a l n o i t c e l e s i n i ) a m (v s c ) v (f l e ) z h ( s s e n t h g i r b m l - t fm / d c 2 3 . 33 . 3 2 r o 1 p m a l9 . 0 27 . 0 8 7 1 4 5 7 . 1 12 . 0 4 s p m a l h t o b1 . 1 30 . 3 74 6 . 0 14 . 6 3 0 . 3 0 . 3 2 r o 1 p m a l9 . 1 24 . 8 74 3 . 1 18 . 8 3 s p m a l h t o b0 . 2 31 . 0 72 8 . 96 . 3 3 2 . 3 2 r o 1 p m a l3 . 1 28 . 9 74 6 . 1 18 . 9 3 s p m a l h t o b4 . 1 33 . 2 79 2 . 0 12 . 5 3 2 . 4 2 r o 1 p m a l3 . 9 12 . 5 83 4 . 2 15 . 2 4 s p m a l h t o b3 . 8 20 . 1 88 5 . 1 16 . 9 3 v d d ) v (v n i ) v ( p m a l n o i t c e l e s i n i ) a m (v s c ) v (f l e ) z h ( s s e n t h g i r b m l - t fm / d c 2 3 . 33 . 3 1 l e8 . 3 23 . 1 8 7 1 4 9 7 . 0 19 . 6 3 2 l e9 . 0 27 . 0 85 7 . 1 12 . 0 4 s p m a l h t o b2 . 4 37 . 1 79 5 . 98 . 2 3 1 2 3 4 8 7 6 5 v dd com control gnd el2 l x c s hv832mg el lamp 2 4.7 f 390 h 1n914* 3.3nf 100v 0.1 f + - v dd + - v in HV832DB1 schematic el1 el lamp 1 en-sw re** ce** 10nf 10k ? * 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. lx = 390 h murata ( lqh32cn391k21)
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