Supertex inc. HV823DB1 EL Driver Demoboard General Description Specifications The HV823DB1 EL Driver demoboard contains all the circuitry necessary to drive an EL (Electroluminescent) lamp. Simply connect it to a power supply and a lamp as shown below. Parameter The supplied circuit has been optimized to drive an 8.0in2 lamp from a 3.0 to 3.3V supply. The circuit may be customized with different component values to suit a particular application. To assist in customization, various circuits optimized for a variety of applications are provided. For additional assitance in designing EL driver circuits, please refer to AN-H34 (HV823 & HV825 EL Lamp Driver Circuits). Lamp size range 3.0 to 12in2 Lamp frequency ~260Hz Converter frequency ~50KHz Value Supply voltage 3.0 to 3.3V Supply current ~50mA Board Layout and Connections Enable Off connect together On CDD RSW REL CSW EN VA VDD 3.0 - 3.3V GND 823 L VIN C D C VB EL Lamp HV823DB1 Connections: EN - Enable Input Enables/disables the lamp driver. A logic high (VDD) enables the driver and a logic low (GND) disables the driver. This input may be connected to a mechanical switch as shown, or to a logic circuit output that has a source impedance of less than 20KΩ. VDD - IC Supply Supplies the HV823 EL driver IC. The supplied circuit is optimized for 3.0V to 3.3V operation. Current draw is typically 100µA when enabled and less than 1µA when disabled. Doc.# DSDB-HV823DB1 B032114 VIN - Inductor Supply Supplies the high voltage power converter. Current draw is approximately 50mA. GND - Circuit Ground Connect to VDD negative terminal. Supply bypass capacitors for both VDD and VIN are provided on the demoboard. An external supply bypass capacitor is not necessary. VA and VB - Lamp Connections Connect to EL lamp of 3 to 12 square inches. Polarity is irrelevant. Supertex inc. www.supertex.com HV823DB1 HV823DB1 Circuit Schematic Enable REL-Osc 3.0MΩ ON = VDD OFF = GND VDD RSW-Osc 1.0MΩ Note 1 VIN L 220µH CDD 100nF D 1N4148 CIN 4.7µF CS 10nF CSW 1.0nF VDD REL RSW VA CS VB LX GND EL Lamp HV823 GND Note: 1. Tie VDD and VIN together if split suppies are not used. CDD is not needed when a single supply is used. Modifiying the Supplied Circuit order of lamp size, along with supply voltages and component values. Find the circuit that most closely matches the desired application and change components as needed. For component locations, refer to the board layout and connection diagram at the begining of this note. The supplied circuit is optimized to drive an 8.0in2 green lamp from a 3.0 to 3.3V supply. To better suit other applications, the circuit may be modified by changing one or more of the components. The following table lists various applications in (ft-lm) Lamp Color Lamp Freq 1.5 4.8 Green 260 3.0 same 1.7 6.6 Green 400 3.0 3.5 6.2 Green 400 6.0 3.0 Green 7.0 5.8 7.0 Lamp Size Lamp1 Brightness VDD VIN Current VIN2 Component Values (µH) (MΩ) (KΩ) (nF) CS CSW 10 1000 3.3 680 100 none 1.0 - 1.5 35 220 2.0 1000 100 none 3.3 same 25 560 2.0 750 100 none 170 3.3 same 21 560 5.1 680 100 none Green 400 5.0 same 30 560 2.0 680 10 1.0 7.8 Green 400 9.0 same 23 560 2.0 680 10 1.0 8.0 6.2 Green 400 5.0 same 30 560 2.0 820 10 1.0 9.0 4.7 White 800 5.0 12 12 560 1.0 330 100 1.0 10 4.1 Green 260 5.0 same 22 1000 3.3 680 10 1.0 12 5.2 Green 260 3.3 same 51 220 3.0 680 10 none 12 3.2 Green 260 5.0 same 19 560 3.0 330 10 1.0 13 3.1 White 400 5.0 same 34 560 2.0 680 10 1.0 13 6.6 White 400 9.0 same 35 560 2.0 680 10 1.0 23 2.1 Green 250 3.3 same 48 330 3.3 1000 10 1.0 (in2) (Hz) (V) (V) (mA) L 3 REL RSW (nF) Notes: 1. Lamp brightness can vary by type and manufacturer. 2. ‘same’ in the VIN column indicates that VIN and VDD are connected together to the same power supply. 3. The recommended inductor is a Murata LQH4N series. Other inductors may be used, however, different inductor characteristics (especially series resistance) may result in overall circuit performance different from that listed. Please refer to Application Note AN-H33 for more information. Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com) Supertex inc. ©2014 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSDB-HV823DB1 B032114 2 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com