Supertex inc. HV9930DB2 Boost-Buck High Brightness LED Driver Demoboard General Description The HV9930DB2 is a LED driver demoboard capable of driving 4 3-watt LEDs in series from an input of 9 - 25V DC. The demoboard uses Supertex’s HV9930 in a boost-buck topology. The converter has excellent line and load regulation over the entire input and output voltage range. The full load efficiency of the converter is typically greater than 80%. The converter is also protected against open LED and output short circuit conditions. Specifications Parameter Value Input voltage (steady state): Output LED string voltage: Output current: 9V – 25V DC 16V max 750mA +/-5% Output current ripple: 20% typical Switching frequency: variable 135kHz (typical at 13V input) Efficiency: Open LED protection: Included; clamps at 20V Output short circuit protection: Included; limits current at 750mA Input current limit: PWM dimming frequency: Dimensions: 2.25A Up to 1.0kHz 58mm X 35mm Board Layout and Connection Diagram _ VIN PWM Dimming + - + 3 2 + 1 Enable Actual Size:58mm X 35mm Connections: Input - The input is connected between the terminals of connector J1 as shown in the Connection Diagram. between terminals 1 and 3 of connector J3 as shown by the dotted lines. Output - The output is connected between the terminals of connector J2 as shown. Note: During PWM dimming, pin 2 of connector J3 should be left open. Also, the PWM signal must have the proper polarity with the positive connected to pin 1 of J3. Note that pin 3 of J3 is internally connected to the return path of the input voltage. Enable/PWM Dimming - To just enable the board, short pins 1 and 2 of connector J3 as shown. To PWM dim the board, connect the external push-pull square wave source Doc.# DSDB-HV9930DB2 A032913 Supertex inc. www.supertex.com HV9930DB2 Testing the Demoboard Fig.2 shows the output current variation over the input voltage range at full load. The LED current has a variation of about 5.0mA over the entire voltage range. Normal Operation: Connect the input source and the output LEDs as shown in the Connection Diagram and enable the board. The LEDs will glow with a steady intensity. Connecting an ammeter in series with the LEDs will allow measurement of the LED current. The current will be 750mA +/- 5%. Output Current (A) 0.747 Open LED test: Connect a voltmeter across the output terminals of the HV9930DB2. Start the demoboard normally and once the LED current reaches steady state, unplug one end of the LED string from the demoboard. The output voltage will rise to about 20V and stabilize. 16 20 24 Output Current (A) 0.748 0.746 0.744 2 6 10 14 18 Output Voltage (V) Fig. 3. Load Regulation of the Output Current Switching Frequency (kHz) Fig. 4 shows the variation of the switching frequency over the input voltage range at full load. The frequency varies from 90kHz to 180kHz over the entire input voltage range. 90 Efficiency (%) 12 Fig.3 shows the variation of the output current with varying output voltage (different number or LEDs) at 13V input. Fig.1 shows the efficiency plot for the HV9930DB2 over the input voltage range. The converter has efficiencies greater than 80% over 13V input. 85 80 75 16 20 24 Input Voltage (V) 200 160 120 80 8 12 16 20 24 Input Voltage (V) Fig. 4. Switching Frequency Regulation Fig. 1. Efficiency vs Input Voltage Doc.# DSDB-HV9930DB2 A032913 8 Fig. 2. Line Regulation of the Output Current Typical Results 12 0.741 Input Voltage (V) PWM Dimming: With the input voltage to the board disconnected, apply a TTL compatible, push-pull square wave signal between PWMD and GND terminals of connector J3 as shown in the Connection Diagram. Turn the input voltage back on and adjust the duty cycle and / or frequency of the PWM dimming signal. The output current will track the PWM dimming signal. Note that although the converter operates perfectly well at 1.0kHz PWM dimming frequency, the best PWM dimming ratio can be obtained at lower frequencies like 100 or 200Hz. 8 0.743 0.739 Short Circuit Test: When the HV9930DB2 is operating in steady state, connect a jumper across the terminals of the LED string. Notice that the output current will remain steady. 70 0.745 2 Supertex inc. www.supertex.com HV9930DB2 The waveforms in Fig. 5 show the drain voltage of the FET (channel 2 (pink); 20V/div) and the LED current (channel 4 (green); 500mA/div) at two different operating conditions – 12V input and 24V input. Fig. 7 shows the PWM dimming performance of the HV9930DB1 with a 250Hz, 5.0V square wave signal. The converter can easily operate at PWM dimming duty cycles from 1% - 99%. Fig. 5 Drain Voltage and LED Current Waveforms in Steady State Fig. 7 PWM Dimming Performance (a) - 1% (a) (b) - 50% (b) Fig. 6a shows the drain (channel 2 (pink); 20V/div) and input current (channel 4 (green); 500mA/div) waveforms during startup and Fig. 6b shows the drain waveform (channel 2 (pink); 20V/div) and the output current (channel 4 (green); 500mA/div) during startup. Fig. 6 Startup Waveforms (c) - 99% (a) (b) Doc.# DSDB-HV9930DB2 A032913 3 Supertex inc. www.supertex.com HV9930DB2 Fig. 8 shows the rise and fall times of the output current during PWM dimming. The converter has nearly symmetric rise and fall times of about 8.0µs. These rise and fall times can be reduced (if desired) by reducing the output capacitance C6. However, this will lead to increased ripple in the output current. Fig. 8 Dynamic Performance during PWM Dimming (a) - Rise Time (b) - Fall Time Doc.# DSDB-HV9930DB2 A032913 4 Supertex inc. www.supertex.com Doc.# DSDB-HV9930DB2 A032913 5 J3A 1 2 J3B 3 J3C 2 J1B 1 REF C2 4.7µF 25V C8 2.2µF 16V R6 10kΩ VIN– C2 4.7µF 25V 5 2 6 VIN REF PWMD CS1 GND CS2 GATE HV9930 VDD U1 D4 1N4148 R4 4.42kΩ C2 4.7µF 25V B220-13 D1 1 3 J1A 7 4 8 1 R5 10Ω 2 C7 0.1µF 16V Q2 FMMT2907A R3 0.39Ω 1/2W R1 0.47Ω 1/2W UP4B-151 L1 REF 1 Q1 IRF7452 R2 8.2Ω 1/2W C5 15µF 50V D3 B2100-13 C1 2.2µF 50V 1 R9 100Ω R8 1.28Ω 1/4W R7 1.28Ω 1/4W D2 20V 500mW DR125-221 L2 R11 10kΩ R10 4.32kΩ 2 REF 2 J2B C6 0.1µF 25V 1 J2A HV9930DB2 Board Layout and Connections Supertex inc. www.supertex.com HV9930DB2 Top Layer Bottom Layer Silk Screen Doc.# DSDB-HV9930DB2 A032913 6 Supertex inc. www.supertex.com HV9930DB2 Bill of Materials # Quan Ref Des C1 Description Package Manufacturer Manufacturer’s Part Number 2.2µF, 50V, X7R ceramic chip capacitor SMD1210 TDK Corp. C3225X7R1H225K SMD1210 Panasonic ECJ-4YB1E475K SMT Nichion UUD1H150MCL1GS 1 1 2 3 3 1 C5 15µF, 50V electrolytic capacitor 4 1 C6 0.1µF, 25V, X7R ceramic chip capacitor SMD1206 Panasonic ECJ-3VB1E104K 5 1 C7 0.1µF, 16V, X7R ceramic chip capacitor SMD0805 Panasonic ECJ-2VB1C104K 6 1 C8 2.2µF, 16V X7R ceramic capacitor SMD0805 TDK Corp. C2012X7R1C225K 7 1 D1 20V, 2.0A schottky diode SMB Diodes Inc. B220-13 8 1 D2 20V, 500mW zener diode SOD123 ON Semi MMSZ5250BT1 9 1 D3 100V, 2.0A schottky diode SMB Diodes Inc. B2100-13 10 1 D4 75V, 400mW switching diode SOD123 Diodes Inc. 1N4148W-7 11 2 J1,J2 2 pin, 2.5mm pitch right angle connector Thru-Hole JST Sales S2B-EH 12 1 J3 3 pin, 2.5mm pitch right angle connector Thru-Hole JST Sales S3B-EH 13 1 L1 150µH, 1.7A rms, 3.0A sat inductor SMT Coiltronics UP4B-151 14 1 L2 220µH, 1.19A rms, 1.51A sat inductor SMT Coiltronics DR125-221 15 1 Q1 100V, 4.5A N channel MOSFET SO-8 IR IRF7452 16 1 Q2 -60V, 600mA PNP transistor SOT-23 Zetex Inc. FMMT2907ATA 17 1 R1 0.47Ω, 1/2W, 5% chip resistor SMD2010 Panasonic ERJ-12ZQJR47U 18 1 R2 8.2Ω, 1/2W, 5% chip resistor SMD2010 Panasonic ERJ-12ZYJ8R2U 19 1 R3 0.39Ω, 1/2W, 5% chip resistor SMD2010 Panasonic ERJ-12ZQJR39U 20 1 R4 4.42kΩ, 1/8W, 1% chip resistor SMD0805 Yageo 9C08052A4421FKHFT 21 1 R5 10Ω, 1/8W, 1% chip resistor SMD0805 Yageo 9C08052A10R0FKHFT 22 2 R6,R11 10kΩ, 1/8W, 1% chip resistor SMD0805 Yageo 9C08052A1002FKHFT 23 2 R7,R8 1.28Ω, 1/4W, 1% chip resistor SMD1206 Yageo 9C12063A1R28FGHFT 24 1 R9 100Ω, 1/8W, 1% chip resistor SMD0805 Yageo 9C08052A1000FKHFT 25 1 R10 4.32kΩ, 1/8W, 1% chip resistor SMD0805 Yageo 9C08052A4321FKHFT 26 1 U1 Boost-Buck LED Driver 8-Lead SOIC Supertex HV9930LG-G C2,C3,C4 4.7µF, 25V X5R ceramic capacitor 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-HV9930DB2 A032913 7 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com