Supertex inc. HV9923DB1 Universal Off-line LED Driver Demoboard Introduction The Supertex HV9923DB1 demoboard is a complete LED power driver to supply a string of LEDs using the HV9923, an integrated 3-pin high input voltage constant-current buck regulator IC. The HV9923 integrates a 500V switching MOSFET and can operate directly from the rectified universal AC line voltage range of 80 to 265VAC. The current in the LED string is internally programmed to 30mA ±15%. The HV9923DB1 is ideally suited for driving strings of LEDs having forward voltage from 20 to 30V at high efficiency (typically 80% at 120VAC). The HV9923DB1 is a peak current-controlled buck converter operating with fixed off-time of 10.5us. Its fixed off-time control scheme provides good stability and tight regulation of the LED current throughout the input AC line voltage range. As its switching frequency varies over the AC line cycle, the HV9923 inherently introduces frequency dither and simplifies the compliance with EMI regulations. Specifications Parameter Input voltage range Load current LED string voltage Value 80 to 265VAC 30mA ± 15% 20 - 30V Conducted EMI CISPR15 Efficiency 80% typ. Board Layout and Connection Diagram LEDL1 C0 HV9923 LED+ U1 D1 CIN LIN LED String VF = 20 to 30V IF = 30mA CDD + D5 D3 D4 CIN2 C2 D2 Connections LED+: Connect the Anode of the LED string to this pin. LED-: Connect the Cathode of the LED string to this pin. AC Line 80 - 265VAC Note: The demoboard is not protected from output open/ short circuit condition. Damage to the demoboard may occur if the output load is not properly connected. AC1, AC2: Connect AC Line to these pins. Doc.# DSDB-HV9923DB1 A032913 Supertex inc. www.supertex.com HV9923DB1 Testing the HV9923DB1 An ammeter can be connected in series with the LED(s) to measure the output current. The average current reading may be smaller than 30mA. This is due to the interruptions in the LED current when the input AC line voltage falls below the forward voltage of the LED string. The average current will also vary over the AC line voltage range. Additional hold-up capacitance can be included across CIN, if these interruptions are not desirable. Connect the LED string to the output terminals. Check the polarity of the LED connection, anode end of the string should be connected to the positive output, cathode should be connected to the negative output. Connect the AC input to the input terminals. Apply the AC voltage at the input terminals and the LED string should start to glow. The HV9923DB1 will regulate constant 30mA current in the LED. Schematic Diagram D2 D4 LIN D3 CIN CIN2 D1 CO LED1 - LED8 D5 U1 HV9923 VRD1 L1 3 VDD AC Line 85-265V CDD F1 DRAIN 1 GND 2 Bill of Materials Reference Description Part Number Manufacturer CIN 0.1µF, 400V, metalized polyester film ECQ-E4104KF Panasonic CIN2 0.033µF, 400V, metalized polyester film ECQ-E4333KF Panasonic CO 0.01µF, 100V, X7R, MLCC B37981M1103K054 Epcos CDD 0.1µF, 50V, X7R, MLCC B37987F5104K054 Epcos L1 33mH, 46mA, mini-drum RL-5480-3-33000 Renco Electronics LIN 2.2mH, 64mA, axial CTH6-222K Central Technologies D1 Diode, UF 600V 1.0A 75ns MUR160 On Semiconductor D2-5 Diode, 600V 1.0A 1N4005 Diodes, Inc VRD1 Surge absorber ERZ-V05D431 Panasonic U1 LED Driver IC HV9923N3-G Supertex, Inc F1 Integrated PCB fuse N/A N/A 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. ©2013 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSDB-HV9923DB1 A032913 2 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com