Supertex inc. HV9861ADB2 HV9861A LED Driver Demoboard Boost Assisted, Valley Fill, 120VAC Input, 7W Output, 350mA, 20V, Power Factor ~ 93% General Description Certain target markets for LED lighting require a power factor of at least 90%. A power factor over 90% can be attained using valley fill power factor correction with the addition of a small boost converter. The boost converter lowers line current distortion by adding line current draw in the valley and lowering the peak amplitude of the valley fill capacitor recharging current. Circuit add-ons with boost secon PF 93.6 % Basic valley fill circuit operation A valley fill power factor correction circuit operates in two distinctly different modes. During a first period, here referred to as the valley and coinciding with line voltage being lower than half the peak line voltage, the load is exclusively powered from two energy storage capacitors. Consequently, in the valley the line current is equal to zero. The valley, being characterized by a line voltage less than half the peak line voltage, extends 30° on either side of the line voltage zero crossing. During a second period, coinciding with the line voltage being higher than half the peak voltage, the load is exclusively powered from the line and not from the valley fill capacitors. Consequently, the line current is not zero. Furthermore, an additional line current is drawn near the peak of the line voltage for recharge of the valley fill capacitors. The two line current components can clearly be identified in the oscillogram of the line current. Boost converter operation The boost converter adds current draw in the valley, thereby lowering distortion and raising power factor. Doc.# DSDB-HV9861ADB2 A032713 without boost secon PF 90.8 % The boost converter switch, a bipolar transistor in common base configuration, is driven indirectly by the current flow in the valley capacitors. In the valley, current is extracted from the valley capacitors during ON time of the main switch, each capacitor contributing half of the load current. The capacitor current in one of the capacitors develops a voltage of about 1.2V across two diodes in series. This voltage provides a forward bias for the base emitter circuit of the boost transistor. Current develops in the boost inductor, which subsequently flows in to the valley capacitors during OFF time. The boost converter develops a line current with an amplitude which is line voltage dependent. When line voltage is particularly small the boost converter operates in discontinuous mode (DCM) and when the line voltage approaches half the peak voltage the converter operates in continuous conduction mode (CCM). The line current amplitude increases nonlinearly with line voltage in either conduction mode. The boost converter action results in delivery of power to the valley capacitors thereby lowering the amplitude of the capacitor recharging current during the second period. Supertex inc. www.supertex.com HV9861ADB2 Specifications Parameter Value Parameter Value Input voltage 100 … 135VAC Efficiency ~80% Output voltage 20VDC, ±10% Output current ripple (at FSW) 80%PP (See note) Output current 350 mADC, ±5% Output open circuit protection Yes Output power 7W Output short circuit protection Yes Power factor ~93.6% Switching frequency 50kHz … 60kHz Total harmonic distortion ~35% Dimensions 54mm x 24mm x 20mm EMI limits CISPR 15 Note: Output current ripple can be reduced in straightforward manner by increasing inductor L3. Alternatively, capacitor C4 can be increased. Connection Diagram 20VDC 120VAC Connections Connect the mains voltage at the input terminals and connect the LED load at the output terminals as shown. Warning: The mains voltage circuit does not contain galvanic isolation. Do not ground any part of the circuit directly to protective ground by means of test equipment connections. Circuit Schematic D1 RM4007 C1 33n R6 2k TP11 AC11 TP22 AC22 AC1 AC2 F1 1A MOV1 S07K140 L2 1.5m L4 1.5m R7 2k L1 1.5m 1 2 BR1 MS380 4 2 R2 100 3 D7 D914 DN1 BAV99 TP31 CAT BLU TP32 C4 220n D6 FMT108 D5 RM4007 2 3 RED L3 1m R1 100 D4 FMT108 1 D3 FMT108 C3 100n 10µ Q1 STX616 3 C5 33n + C2 D2 FMT108 AN0 + C6 10µ 1 1 VIN 5 7 PWMD GATE HV9861A LD CS 1 4 2 3 M1 M1N60 2 VDD RT GND 6 C7 100n Doc.# DSDB-HV9861ADB2 A032713 2 8 3 R5 332k R3 2 R4 1.3 Supertex inc. www.supertex.com HV9861ADB2 EMI Signature 100 80 dBμV 60 40 If BW 9.0kHz 10k 100k 1M Hz 10M Notes: PCB suspended approximately 3 inches above reference plane. Peak detector in peak hold mode for 10 min. THD vs. Line Voltage 100 PF vs. Line Voltage 100 80 90 60 80 % % 40 70 20 60 0 80 100 120 VAC 140 50 80 160 Efficiency vs. Line Voltage 100 120 VAC 140 160 Output Current vs. Line Voltage 500 90 100 400 300 80 mA % 70 200 60 100 50 80 100 Doc.# DSDB-HV9861ADB2 A032713 120 VAC 140 0 160 3 80 100 120 VAC 140 160 Supertex inc. www.supertex.com HV9861ADB2 Line Voltage and Line Current at Nominal Line and Load Line Current and Output Current at Nominal Line and Load Doc.# DSDB-HV9861ADB2 A032713 4 Supertex inc. www.supertex.com HV9861ADB2 HV9861ADB2 (top view) HV9861ADB2 (bottom view) Actual Dimensions: 130mm x 81mm Silk Screen Doc.# DSDB-HV9861ADB2 A032713 5 Supertex inc. www.supertex.com HV9861ADB2 Bill of Materials Qty Ref Description Mfr Part Number 1 BR1 Bridge rectifier 500mA 380VAC 800VRRM SMD Diotec MS380 1 R1 Resistor thick film 1/8W 1% SMD 1206 100Ω Yageo RC1206FR-07100RL 1 R2 Resistor thick film 1/8W 1% SMD 0805 100Ω Yageo RC0805FR-07100RL 1 R3 Resistor thick film 1/8W 1% SMD 0805 2Ω Yageo RC0805FR-072RL 1 R4 Resistor thick film 1/8W 1% SMD 0805 1.3Ω Yageo RC0805FR-071R3L 1 R5 Resistor thick film 1/8W 1% SMD 0805 332kΩ Yageo RC0805FR-07332KL 2 R6, R7 Resistor thick film 1/8W 1% SMD 1206 2kΩ Yageo RC1206FR-072KL 1 C7 Cap ceramic X7R 10% 50VDC SMD 0805 100nF Yageo CC0805KRX7R9BB104 1 C4 Cap poly metalized 10% 125C 160VAC 250VDC 10mm 220nF Epcos B32521C3224K 2 C1, C5 Cap poly metalized 5% 125C 160VAC 250VDC 7.5mm 33nF Epcos B32520C3333J 1 C3 Cap poly metalized 10% 125C 160VAC 250VDC 7.5mm 100nF Epcos B32520C3104K 2 C2, C6 Cap electrolytic 105C 12khr 20% 160VDC THD 8x9 10µF Rubycon 160LLE10MEFC8X9 4 D2, D3, D4, D6 Diode ultrafast 1A 600V 35ns SMD SOD-123H Comchip CSFMT108-HF 1 D7 Diode 75V 4ns SMD SOD-123 200mA 400mW Fairchild MMSD914 2 D1, D5 Diode standard 1A 1kV SMD SOD-123F Comchip CGRM4007-G 1 DN1 Diode network BAV99 300mA 75V 4ns SMD SOT-23-3 Diodes Inc BAV99-7-F 1 IC1 IC power management LED driver HV9861A SMD SOIC-8 Supertex HV9861ALG-G 1 Q1 Transistor NPN 2.8W 500V 1.5A THD TO-92AP STX616 ST Micro STX616-AP 1 M1 MOSFET N-channel 600V 1A 8.5R THD IPak STD1NK60 ST Micro STD1NK60-1 1 L3 Inductor THD 5mmLS 8x12mm 1mH 510mA Abracon AIUR-02H-102K 3 L1, L2, L4 Inductor THD 6mm dia 1.5mH 8.0Ω Wuerth 7447462152 1 MOV1 Varistor MOV THD disc 7mm 180VDC 140VAC .2kA 9.5J Epcos S07K140 1 F1 Fuse 300VAC slow TR5 Series 383 1A LittelFuse 38311000000 4 J1, J2, J11, J22 Buswire AWG22 Any … 2 TP11, TP22 Testpoint PCB compact orange Keystone 5013 1 TP31 Testpoint PCB compact red Keystone 5010 1 TP32 Testpoint PCB compact blue Keystone 5127 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-HV9861ADB2 A032713 6 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com