HT7L4661 PIR E27/10W 6S, 381mA LED Bulb

Transcription

1 D/N: AN0394E Features The switching power of this device is designed for PIR E27 LED bulb applications. Its special features are summarised below: Wide AC input voltage range Human infrared detect function When a human body detection is made the system will be activated for a brief period to conserve energy Internal 650V high-voltage start-up circuit for quick startup and improved system efficiency Non-isolation buck topology system architecture Provides a 5V LDO output and has few external component requirements High efficiency, high power factor and low THD universal input voltage Insensitive to ambient temperature changes High constant current accuracy and good load regulation Full range of protective features such as LED open load protection, short circuit protection and internal over temperature protection Simple system architecture design Typical System Characteristics 6 series LEDs, =381mA / Open Frame Input AC Frequency Description Output Voltage (V LED+) Output Current (I OUT) Output Current Ripple Linear Regulation European (180V AC~265V AC) 47Hz~63Hz 14V DC~24V DC 381mA(typ) 250mA(max) Ta = 25 C 0% / -2.5% 0% / -2.5% Wide Range (90V AC ~265V AC) Ta = -20 C ~ 85 C +0.5% / -4% +0.5% / -4% Load Regulation Ta = 25 C -2.5%@115V AC, -2.5%@220V AC Efficiency Power Factor Standby Power Consumption Output Short Circuit Power Consumption Output Short Circuit Protection Output Open Circuit Protection PIR sense distance >83%@115V AC, >81%@220V AC >0.98@115V AC, >0.93@220V AC <0.1W@115V AC, <0.2W@220V AC <1W@115V AC, <1W@220V AC Yes Yes 6M Note: The output current may vary due to sense resistance errors and soldering impedance. V / 13 AN0394E

2 Application Circuit and BOM F1 C1 C3 R1 BD1 L2 Q1 Rcsa1 L3 VLED+ Rcsb1 C6 D1 C7 R13 L1 VLED- C14 C8 R12 D2 R9 R10 R HV N.C 3 DRV DIM CS COMP REG5V 6 5 GND 4 VCC HT7L ZCD U3 C13a C13 C13b CY1 C12 RY1 R16 5V C4 R8 3 VSS C9a 4 2 OUT VDD PIR Controller VCAP TON SENS R7 R14 7 CDS C5 C5a U1 Cr14 D G S PIRIN 1 U2 C10 C9 Cr2 R2 R5 5V R15 C11 R3 R6 Cr3 BOM Component Package Parameter Manufacturer R1 R2 SMD0603 RES 15K R3 SMD0603 RES 560K R5 SMD0603 RES 100K R6,R7 SMD0603 RES 1M R8 SMD0603 RES 20K R9 SMD1206 RES 30K R10 SMD0603 RES 240R R11 SMD0603 RES 82K R12 SMD0603 RES 100R R13 SMD1206 RES 2.4K R14 R15 SMD0603 RES 56K R16 SMD0603 RES 22K Rcsa1 SMD0805 RES 1R1 Rcsb1 SMD0805 RES 1R0 RY1 C1 Dip X Cap 0.1µF/250V C3 C4, C5, C5a, C9a, C13a, C13b, Cr2 SMD0603 CE 0.1µF C6 Dip ML 0.068µF/450V V / 13 AN0394E

3 Component Package Parameter Manufacturer C7 Dip 10 20mm EL 470µF/35V 105 C C8 SMD1210 CE 10µF/50V 105 C C9 Dip 8 12mm EL 330µF/25V 105 C Nichicon PJ(M) C10 Dip 6.5 8mm EL 33µF/50V 105 C C11,C12 SMD0603 CE 33NF C13 Dip mm EL 33µF/25V 105 C C14 SMD0603 CE 0.47µF Cr3 Cr14 CY1 BD1 SMB Diode Bridge 1A/400V, B4S D1 SMB Ultra Diode 2A/600V, ER2J PAN JIT D2 SMB Ultra Diode 1A/600V, ES1J PAN JIT Q1 TO-252 MOSFET 5A/600V, FDD5N60Nz L1 DR 8 10 DR CORE 3.3MH L2 Jump Wire L3 EE13 Inductor 252µH (AWG27, 68turns) F1 Dip Fuse 1.25A/250V U1 PIR Controller U2 TO-5 D205B U3 10MSOP HT7L4661 HOLTEK PCBA L W H(mm) Inductor Specification (L3) Transformer EE13 SPEC mm X 68Ts 2 Tape 2Ts Tape 2Ts mm x 17Ts 0.36mm x 17Ts 0.36mm x 17Ts mm x 17Ts Tape 2Ts Tape 2Ts Need Gap: 2pin - 4pin L=250uH 1KHz/ 1V V / 13 AN0394E

4 System Board Introduction Top View Note Non 1:1 Scale Bottom View Functional Description The HT7L4661 is an LED lighting controller implemented using buck architecture. It has the advantages of high power factor, high output current accuracy and requires few external components. It is insensitive to ambient temperature variations and has a simple system parameter setup. Its unique real current control methodology can control LED current values accurately to ensure the system is able to maintain stable LED current output conditions under its full voltage input range, a variety of LED string numbers and effects of inductor tolerance. The HT7L4661 has a high power factor and operates in the boundary conduction mode for current control. Its power factor correction capability can easily maintain excellent system performance and acehive power factor values in excess of 0.9 even under full voltage input conditions. In addition, operating in the boundary conduction mode can reduce system switching losses and consequently achieve better system EMI characteristics. The internal 650V high-voltage start-up switch can help speed up the system start-up time and reduce unnecessary power consumption thus improving the system efficiency. Additionally the HT7L4661 provides a 5V LDO output which can simplify the external circuitry and reduce the required number of external components. V / 13 AN0394E

5 The HT7L4661 also provides a range of system protection functions including output short circuit protection, output over current protection (cycle by cycle current limit), output over voltage protection, IC over voltage protection and over temperature protection. Pin Description HT7L4661 Pin Description VCC The VCC pin is used for the device power supply. The following suggestions should be noted in applications: 1. VCC to Ground Capacitor (C8): this capacitor is used to ensure that the IC operates with a stable power source so that the system will not generate an abnormal secondary start-up action. This capacitor value is suggested to be at least 10µF. 2. The UVLO ON voltage on the VCC pin is 16V (Typ.). The VCC operating voltage formula is defined as follows: 29 V > ( VCC = V + VD ) 8. V LED 2 > 4 Note: Since the VCC pin supports a VCC OFF voltage of 8.4V (Typ.) and an OVP voltage of 29V (Typ.), for normal operation, the VCC value muse be confined within a range of 8.4V to 29V. In this application example, when the LED string number is too large or when an open load condition occurs the VCC pin can be used for system protection. Note: (1) Due to the V LED+ ripple voltage characteristic the maximum peak voltage must be taken into consideration in the calculation. (2) In normal operation, the suggested VCC operating voltage is within a range of 16V~18V. (3) Under conditios of open load, the maximum output voltage is: VLED + ( VCCOVP VCC) +. (4) The output capacitor (C7) rated voltage must be higher than the open load voltage. HV The HV pin is mainly used for the device high-voltage start-up and also can be used as the power input for the REG5V when the system enters the standby mode. The following suggestions should be noted in applications: 1. The high voltage power charges the external VCC pin (Pin4) capacitor via the HV pin (Pin1). When the VCC voltage has exceeded the VCC ON, the system will start up. 2. When the system enters standby mode with the VCC power off, the high voltage power can still provide power to the REG5V (Pin6) via the HV pin. 3. Although there is a 650V high voltage start-up switch on the HV pin, a buffer resistor (R9) is still required to be connected between the HV pin and the high voltage power. The resistance value can be adjusted according to the user requirements. V / 13 AN0394E

6 DRV The DRV output pin is used to drive the external power MOSFET. In order to enable this output to match most MOSFET types, the device restrains the DRV pin maximum output voltage to a maximum of 19.5V. REG5V The REG5V pin is the 5V LDO output pin. Its power can be sourced from the HV pin or the VCC pin depending on the system operating mode. If the VCC voltage is lower than VCC OFF, then its power will be sourced from the HV pin and the output current will be at least 1mA. If the Vcc voltage has a value between VCC OFF and VCC OVP, the power will be sourced from the VCC pin and the output current will be at least 5mA. To maintain the REG5V output voltage stability, the output capacitor (C13) value is suggested to be larger than 1µF. ZCD The VCC pin power source is from the system power. But because of the power supply circuit structure, the VCC pin may not be able to detect that a system output over voltage condition has occurred. To ensure safe system operation the device provides another output OVP design, which detects over currents (>300µA) via the ZCD resistor (R11) to determine when an over voltage condition occurs. The parameter setup is shown below: VLED + ( open) 3 = R11 300uA CS The output current can be easily set by using external resistors (Rcsa1//Rcsb1). The formula is: I OUT = R csa 0.2 1// R For a more accurate output current the resistance precision error must be less than 1% csb1 and the related PCB lines should be as short as possible. The inductor parameter is calculated as shown below: While fs _ min Po π ( 2Vac _ min VLED+ ) Iπk = 2 π η ( 2Vac _ min VLED + cos( θ ) VLED + ( θ )) 2 VLED + VLED + L = (1 ) fs _ min Ipk 2Vac _ min θ = Po = VLED + IOUT sin 1 ( = Minimum Switching Frequency. VLED + ) 2Vac _ min V / 13 AN0394E

7 COMP There is an external capacitor (C14) connected to ground whose purpose is to stabilise the internal reference signal. The suggested capacitor value is 0.47µF. DIM The DIM pin (Pin8) is the dimming signal input pin. When the voltage variation is between 0.4V and 3V, the device will be operating in its linear dimming range and the output current can be controlled by changing the pin voltage. Here a DC voltage variation of 0.4V~3V corresponds to an output current adjustment rate of 13.3%~100%. Experimental Results AC input voltage range: 90V AC~265V AC. LED load: 6S2P, total input power: 9W. V AC Pin(W) V LED+ (V DC) P OUT(W) Efficiency (%) PF Note (ma) V AC LED string number LED current (ma) PF LED current (ma) PF Note: The output current may vary due to sense resistance errors and soldering impedance. V / 13 AN0394E

8 AC Power Turn-on 115Vac Fig 1. Start-up Time (115V AC) 230Vac AC Power Turn-off Fig 2. Start-up Time (230V AC) 115Vac Fig 3. Turn-off Delay Time (115V AC) 230Vac Fig 4. Turn-off Delay Time (230V AC) V / 13 AN0394E

9 AC Power Iac_in 115Vac Fig 5. Input Voltage/Current (115V AC) Iac_in 230Vac LED Voltage/Current Ripple Fig 6. Input Voltage/Current (230V AC) Fig 7. Output Voltage/Current Ripple (115V AC) Fig 8. Output Voltage/Current Ripple (230V AC) V / 13 AN0394E

10 Protection (1): Remove LED load after AC Power turn-on Fig 9. Open Load Protection-1(90V AC) Fig 10. Open Load Protection-1 (265V AC) Protection (2): Remove LED load before AC Power turn-on Fig 11. Open Load Protection-2 (90V AC) Fig 12. Open Load Protection-2 (265V AC) V / 13 AN0394E

11 Protection (3): Short LED Load after AC Power turn-on 115Vac Fig 13. Short Load Protection-3 (115V AC) 230Vac Fig 14. Short Load Protection-3 (230V AC) Protection (3): Short LED Load before AC Power turn-on 115Vac Fig 15. Short Load Protection-4 (115V AC) 230Vac Fig 16. Short Load Protection-4 (230V AC) V / 13 AN0394E

12 System Performance 84% Efficiency (%) 83% 82% 81% 6S, 381mA 80% AC Input (VAC) Fig 17. Efficiency vs. AC Input voltage (ma) S, 381mA AC Input (VAC) Fig 18. Regulation vs. AC Input Voltage Power Factor (PF) S, 381mA AC Input (VAC) Fig 19. Power Factor (PF) vs. AC Input Voltage (ma) Vac 115Vac 180Vac 240Vac 100Vac 135Vac 220Vac 265Vac 4S 5S 6S 7S LED Series Fig 20. Regulation vs. LED Series number V / 13 AN0394E

13 86% 84% Efficiency (%) 82% 80% 78% 76% 74% 4S, 381mA 5S, 381mA 6S, 381mA 7S, 381mA AC Input (VAC) Fig 21. Efficiency vs. AC Input Voltage 1 (Different LED Series) Power Factor (PF) S, 381mA 5S, 381mA 6S, 381mA 7S, 381mA AC Input (VAC) (ma) Fig 22. Power Factor vs. AC Input Voltage (Different LED Series) 6S, 381mA 90Vac 100Vac 115Vac 135Vac 180Vac 220Vac 240Vac 265Vac Ambient Temperature ( ) Fig 23. vs. Ambient Temperature V / 13 AN0394E