Supertex inc. HV9911DB2 Boost LED Driver Demoboard with 1:3000 Dimming Ratio and Excellent Current Regulation General Description Specifications The HV9911DB2 is an LED driver capable of driving up to twenty 100mA LEDs in series from an input of 9 - 16V DC. The demoboard uses Supertex’s HV9911 IC in a boost topology. The converter has a very good initial regulation, (+/-5%), and excellent line and load regulation over the entire input and output voltage range (<+/- 1%). The full load efficiency of the converter is typically greater than 85%. Parameter Input voltage (steady state): Output LED string voltage: Output current: The HV9911DB2 is also protected against open LED and output short circuit conditions. It has an excellent PWM dimming response, with typical rise and fall times less than 2.0μs, which will allow high PWM dimming ratios. The HV9911DB2 also features an ENABLE input which can be used to shut down the IC and allow a very small power draw from the input. Value 9 - 16V DC 35V min - 80V max 100mA +/-5% Output current ripple: 10% typical Switching frequency: 200kHz Full load efficiency: 87% (at 12V input) Shut down current: 100μA (typ) Open LED protection: Output short circuit protection: PWM dimming frequency: Shuts down at 92V Included 1:3000 dimming ratio at 200Hz The switching frequency of the HV9911DB2 can be synchronized to other HV9911 boards or to an external 200kHz clock by connecting the clock to the SYNC pin of the HV9911DB2. Board Layout and Connection Diagram VIN Actual Size: 64mm X 31mm Connections: Input - The input is connected between the terminals of connector J1 as shown in the Connection Diagram. GND of connector J3 as shown by the solid lines. Note that EN should be connected to the input voltage. Output - The output is connected between the terminals of connector J2 as shown. SYNC - To synchronize two or more boards, connect the SYNC pins of all the boards together. To synchronize the HV9911DB1 to an external 200kHz clock, connect the clock between the SYNC terminal and GND pin of terminal J3. Enable - To Enable to board, connect the EN pin of the connector J3 to the input voltage as shown in the Connection Diagram. This will enable the IC and a small current will be drawn from the input. However, this will not start the converter. To start the converter, connect the PWMD pin to the VDD pin of the connector J3. PWM Dimming - To PWM dim the board, connect the external push-pull waveform source between terminals PWMD and Doc.# DSDB-HV9911DB2 A032713 Note: During PWM dimming, pin VDD of connector J3 should be left open. Also, the PWM signal must have the proper polarity with the positive connected to pin PWMD of J3. Note that pin GND of J3 is internally connected to the return path of the input voltage. Supertex inc. www.supertex.com HV9911DB2 Testing The Demoboard: Fig. 1. Efficiency vs Output Voltage Open LED test: Connect a voltmeter across the output terminals of the HV9911DB2. 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 92V and then the HV9911DB2 will shut down. To restart the converter, disconnect and reconnect the input voltage (recycle the power to the board). Short Circuit Test: When the HV9911DB2 is operating in steady state, connect a jumper across the terminals of the LED string. Notice that the output current will immediately go to zero and the converter will shut down. To restart the HV9911DB2, recycle the input power to the demoboard. 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 widest PWM dimming ratio can be obtained at lower frequencies like 100 or 200Hz. Efficiency (%) 88 87 86 35 45 55 65 75 Output Voltage (V) Fig. 2. Efficiency vs Input Voltage 90 89 88 87 86 85 9 11 13 15 Input Voltage (V) Fig. 3. Output Current vs Input Voltage 101 100.5 100 99.5 99 9 11 13 15 Input Voltage (V) 1. Efficiency: The efficiency of the converter at various LED string voltages are shown in Fig.1 (measured at the nominal input voltage of 24V). Fig.2 shows the full load efficiency of the converter at varying input voltages. The minimum efficiency of 86% for the converter occurs at 9V input and full load output. 2. Current Regulation: Figs. 3 and 4 show the output current regulation vs. input voltage and load voltage respectively. The total current regulation (line and load combined) is found to be less than 1%. Output Current (mA) Fig. 4. Output Current vs Load Voltage Typical Results Doc.# DSDB-HV9911DB2 A032713 89 85 Efficiency (%) Current Regulation: With the input power to the converter disconnected, change the LED string voltage within the specifications mentioned. The current output of the HV9911DB2 will remain very steady over the entire load range. Vary the input voltage while the circuit is operational. The current will be regulated over the entire line range. 90 Output Current (mA) 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 100mA +/- 5%. 101 100.5 100 99.5 99 35 45 55 65 75 Output Voltage (V) Supertex inc. 2 www.supertex.com HV9911DB2 3. Open LED Protection: Open LED protection for the circuit is set at 92V. The waveforms in Fig. 5 shows the output voltage, drain voltage and output current during an open LED condition. The time taken for the over voltage protection to shut the IC down will depend on the size of the output capacitor. Fig. 7a: Rise time of LED Current at 80V output (5μs/div) PWM dimming input Fig. 5: Open LED Protection (20μ/div) LED Current Output Voltage Fig. 7b: Fall time of LED Current at 80V output (5μs/div) Output Current Drain Voltage (Q1) PWM dimming input 4. Output Short Circuit Protection: Fig. 6 shows the waveforms for output short circuit condition. The disconnected FET is turned off in less than 300ns. The rise in the output current will depend on the input voltage and the value of inductor L1. The same protection will also help in protecting the LEDs in case the output voltage increases beyond the LED string voltage. LED Current Fig. 8a: Rise time of LED Current at 40V output (5μs/div) Fig. 6: Open Short Circuit Protection (500ns/div) PWM dimming input LED Current Output Voltage Output Current Fig. 8b: Fall time of LED Current at 40V output (5μs/div) 5. PWM Dimming: The rise and fall transitions of the LED current during PWM dimming are shown in Figs. 7 and 8, at output voltages of 80 and 40V respectively. The timescale for all waveforms is set at 5.0μs/div. The rise and fall times are less than 1.0μs in each case. Thus, a PWM dimming ratio of 1:3000 is achievable at a PWM dimming frequency of 200Hz. Doc.# DSDB-HV9911DB2 A032713 PWM dimming input LED Current Supertex inc. 3 www.supertex.com J1A 1 REF REF C2 2.2µF 16V C1 2.2µF 16V R18 R9 6.04kΩ open C7 2.2nF 18.2kΩ C8 6.65kΩ R12 R11 0.1µF 16V C6 REF R4 19.1kΩ R8 open R7 Io_SNS open J3C OVP FAULT CS GATE RT Q3 TP0610T JX;;33 J3A CLIM COMP FDBK IREF REF SYNC U1 1.0µF 16V J10 low standby current J3B C5 R17 100kΩ Q4 10kΩ R16 Used to acheive 10kΩ C10 1.0nF J3D R15 10kΩ VIN 2 VDD PWM 4 SC Doc.# DSDB-HV9911DB2 A032713 GND J1B 1 453kΩ R2 10uH L1 J5 2 J6 J7 R6 0.08Ω 1/4W Q1 FDS3692 (B32529) C4 0.33µF 100V B1100-13 D1 J8 Io_SNS C9 0.33µF 100V J2A J2B R10 3.3Ω 1/8W Q2 VN2110 2 R3 1.13kΩ R1 82.5kΩ 1 HV9911DB2 Circuit Schematic: Supertex inc. www.supertex.com HV9911DB2 Top Layer: Bottom Layer: Silk Screen: Doc.# DSDB-HV9911DB2 A032713 Supertex inc. 5 www.supertex.com HV9911DB2 Bill of Materials Item Quan # RefDes Description Package Manufacturer Manufacturer’s Part Number 1 2 C1,C2 2.2μF, 16V X7R ceramic chip capacitor SMD1206 Murata GRM31MR71C225MA35L 2 2 C4,C9 0.33μF, 100V metal Film capacitors Thru-Hole EPCOS Inc B32529C1334J 3 1 C5 1μF, 16V X7R ceramic chip capacitor SMD0805 TDK Corp 4 1 C6 0.1μF, 16V X7R ceramic chip capacitor SMD0805 Murata 5 1 C7 2.2nF, 5%, 50V C0G ceramic chip capacitor SMD0805 TDK Corp 6 3 - - 7 1 C10 1nF, 50V, X7R ceramic chip capacitor SMD0805 TDK Corp C2012X7R1H102K 8 1 D1 100V, 1A schottky diode SMA Diodes Inc. B1100-13 9 2 J1,J2 Side Entry 2-pin male header Thru-Hole JST Sales Amer. S2B-EH 10 1 J3 Side Entry 4-pin male header Thru-Hole JST Sales Amer. S4B-EH 11 1 L1 10μH, 5.5A sat, 4.3A rms inductor SMT Sumida CDR10D48MN-100 12 1 Q1 100V, 4.55A N-Channel MOSFET SO-8 Fairchild FDS3692 13 1 Q2 100V, 4.0Ω N-Channel MOSFET SOT-89 Supertex VN2110K1 14 1 Q3 -60V, 10Ω P-Channel MOSFET SOT-23 Supertex TP0610T 15 1 Q4 40V, 600mA NPN Transistor SOT-23 ST Micro MMBT2222A 16 1 R1 82.5k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-0782K5L 17 1 R2 453k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-07453KL 18 1 R3 1.13k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-071K13L 19 1 R6 0.08, 1%, 1/4W chip resistor SMD1206 Vishay/ Dale WSL1206R0800FEA 20 1 R8 19.1k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-0719K1L 21 1 R9 6.04k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-076K04L 22 1 R10 3.3, 1%, 1/8W chip resistor SMD0805 Panasonic 23 1 R11 18.2k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-0718K2L 24 1 R12 6.65k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805FR-076K65L 25 1 R15, R16, 10.0k, 1%, 1/8W chip resistor R18 SMD0805 Yageo RC0805JR-0710KL 26 1 R17 100k, 1%, 1/8W chip resistor SMD0805 Yageo RC0805JR-07100KL 27 1 U1 Switchmode LED Driver with High Current Accuracy SO-16 Supertex R4, R7, C8 open C2012X7R1C105K GRM219R71C104KA01D C2012C0G1H222J - ERJ-6RQF3R3V HV9911NG-G 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-HV9911DB2 A032713 6 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com