HT7L4813 E27/12W 26S, 145mA LED Bulb. The switching power is for E27 LED tubes whose characteristics are summarised below:

Transcription

1 HT7L4813 E27/12W 26S, 145mA LED Bulb D/N:AN0389E Features The switching power is for E27 LED tubes whose characteristics are summarised below: Intenal low impedance MOSFETs Operates with wide AC input voltages System architecture is non-isolation BUCK mode High efficiency, high power factor and low THD universal input voltage Low output current variation at high/low ambient temperature High LED current accuracy and good load regulation LED open load protection, short circuit protection and integrated over temperature protection Simple system architecture design Typical System Characteristics 26S, 145mA / Open Frame Description European Wide Range (180V AC~265V AC) (90V AC~265V AC) Input AC Frequency 47Hz~63Hz Output Voltage (V LED+) 44.9V DC~73.7V DC Output Current (I OUT) 145mA(Typ.) Output Current Ripple 150mA(Max.) Linear Ta = 25 C +1.0% / -0.5% +1.0% / -0.5% Regulation Ta = -20 C ~85 C +0.2% / -1% +0.2% / -1% Load Ta = 25 C 115V 220V AC Regulation Ta = -20 C ~85 C 115V 220V AC Efficiency 115V AC, 220V AC Power Factor With EMI Solution 115V AC, 220V AC Without EMI Solution 115V 220V AC THD (Total Harmonic Distortion) 115V AC/220V AC Standby Power Consumption 115V AC, 220V AC Output Short Power Consumption 115V AC, 220V AC Output Short Protection Yes Output Open Protection Yes EMI EN / 20 AN0389E

2 Application Circuit and BOM HT7L4813 E27/12W 26S 145mA LED Bulb R4 90Vac~265Vac F1 C1 L1 TVR1 BD1 + - C4 R1 DRAIN DRAIN CS CS D2 R3 t1 T1 t2 C6 R6 LED+ LED- U1 ZCD VCC COMP GND D3 Rsn1 C2 C5 R2 Csn1 Remi1 Cemi1 R5 Component Package Parameter Manufacturer R1 SMD1206 RES 430K R2 SMD0603 RES 51R R3 SMD0805 RES 2R2 R4 SMD0805 RES 3R6 R5 SMD0603 RES 300K R6 SMD1206 RES 100K RSN1 SMD1206 RES 100R REMI1 SMD1206 RES 10R CSN1 SMD1206 CE 470P/ 1KV CEMI1 SMD1206 CE 220P/ 1KV C1 DIP X-CAP, 0.1uF/250V C4 DIP ML CAP, 0.1uF/250V C6 DIP EL 100μF/100V 105 C C2 SMD0805 CE 1μF/25V C5 SMD1210 CE 10μF/50V BD1 SMB DIODE BRIDGE 1A/400V, B4S PAN JIT D2 SMB ULTRA DIODE 2A/600V, ER2J PAN JIT D3 SMB ULTRA DIODE 1A/600V, ES1J PAN JIT T1 EE-13 MAIN TRANSFORMER EE13, L=400uH L1 DR 8X10MM DR CORE 3.6MH F1 DIP FUSE 1.0A/250V TVR1 GNR07D471K CERAMATE TECHNICAL CO. U1 SOT8 HT7L4813 HOLTEK PCB L W H(MM) / 20 AN0389E

3 HT7L4813 E27/12W 26S 145mA LED Bulb System Board Introduction 26.0 mm 18.0 mm 13.5 mm 43.8 mm 3 / 20 AN0389E

4 Functional Description The device is an LED lighting controller implemented using buck architecture. It has a high power factor and high output current accuracy and also has the advantages of requiring few external components, simple system parameter setup and is insensitive to environmental temperature variations. The specific current control algorithm for the device can accurately control the LED output current. The device can maintain stable system operation with good linear regulation for a full range of AC input voltages, has good load regulation for different LED types and has low sensitivity to external inductor value variations. The HT7L4813 operates at the boundary conduction mode for current control. Its high power factor characteristic allows it to achieve PF>0.9 for a full range AC input voltage conditions. In addition, operating at the boundary conduction mode can reduce system switching power losses and consequently achieve better system EMI characteristics. The device has an extremely low system start-up current and low standby operating current which helps to reduce unnecessary power comsumption and improve the system efficiency. The device 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 and over temperature protection. Pin Description VCC The VCC pin is used as the device power supply. The following suggestions should be noted in user applications: 1. VCC to Ground Capacitor (C5): 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 10µF or more. 2. IC Start-up Resistor (R1): the smaller the start-up resistor value, the higher the start-up speed will be. As the resistance value impacts the system efficiency, the total start-up resistor value should generally be within a range of 300kΩ ~ 600kΩ. 3. The UVLO ON voltage on the VCC pin is 18V (typ.). The VCC operating voltage formula is defined as follows: 29 V > ( VCC = VLED + VZD1 VD2) > 10V Since the VCC pin supports a 10V (typ.) of UVLO OFF voltage and 29V (typ.) of OVP voltage, its operating voltage must be confined between 10V and 29V for normal operation. In addition, when the LED series is too large or when an open load condition occurs the VCC pin can be used for system protection. 4 / 20 AN0389E

5 Note: (3-1) Due to the ripple voltage characteristic, the maximum peak voltage needs to be taken into consideration during the VLED+ calculation. (3-2) For normalnaml operation, the VCC pin is suggested to operate with a range ofbetween 16V toand 18V. (3-3)The maximum output voltage in the open load condition is: V LED+ + (VCCOVP-VCC). (3-4) The output capacitor (C6) voltage must be higher than the open load voltage. ZCD The VCC pin power source comes from the system power. As the power supply circuit may affect the VCC pin OVP function, to ensure properthe secure system operation, the HT7L4811 device provides another output OVP design, which detects the over currents (>300µA) via the ZCD resistor (R5) to determine anthe OVP occurrence. The parameter setup ting is shown below: V 3 = R 300uA LED + ( open) CS The output current can be set via the extarnalexternal resistor (R3/R4) using the following formula: IOUT = 0.2 R3// R4 In order to obtain a more accurate output current, the resistance precision error must be less than 1% and the related PCB lines should be as short as possible. The inductor parameter is calculated as shown below: 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 ZCD And Po = VLED + IOUT θ = sin 1 ( fs _ min =Minimum Switching Frequency VLED + ) 2Vac _ min COMP This is an externally connecteds a capacitor (C2) to ground, which is used to stabilise the internal reference signal. The suggested capacitor value is suggested to be 1.0µF. DRAIN The maximum input voltage of its DRAIN pin is 500V DC. 5 / 20 AN0389E

6 Experimental Results Test Condition: with EMI solution. AC input voltage range: 90V AC~265V AC. LED load: 26S/1P; total input power: 12W. V AC Pin(W) V LED+(V DC) Iout(mA) P OUT(W) Efficiency (%) PF THD(%) V AC LED series LED current (ma) PF LED current (ma) PF Note: The output current may vary due to sense resistance errors and soldering impedance. 6 / 20 AN0389E

7 AC Power Turn-on CH2 Iout:145mA 442mS CH3 Vin 115Vac Fig 1. Start-up Time at 115V AC CH2 Iout 145mA 140mS CH3 Vin 230Vac Fig 2. Start-up Time at 230V AC 7 / 20 AN0389E

8 AC Power Turn-off 11mS CH2 Iout CH3 Vin 115Vac Fig 3. Turn-off Delay Time at 115V AC 13.8mS CH3 Vin 230Vac CH2 Iout Fig 4. Turn-off Delay Time at 230V AC 8 / 20 AN0389E

9 DC Output CH2 Iout CH3 Vout: 79.6V Fig 5. Input AC Voltage/Current at 115V AC CH2 Iout CH3 Vout: 81V Fig 6. Input AC Voltage/Current at 230V AC 9 / 20 AN0389E

10 I AC /V AC Iac Vac Fig 7. Input AC Voltage/Current at 115V AC Iac Vac Fig 8. Input AC Voltage/Current at 230V AC 10 / 20 AN0389E

11 LED Voltage/Current Ripple 141mA CH2 Iout CH3 Vout Fig 9. Output Voltage/Current Ripple at 115V AC 142mA CH2 Iout CH3 Vout Fig 10. Output Voltage/Current Ripple at 230V AC 11 / 20 AN0389E

12 Protection (1): Open Load after AC Power Turn-on CH2: Iout CH1: Vout 92.8V CH3: AC Vin Fig 11. Open Load Protection at 115V AC CH2: Iout CH3: AC Vin CH1: Vout 93.6V Fig 12. Open Load Protection at 265V AC 12 / 20 AN0389E

13 Protection (2): Open Load before AC Power Turn-on CH1: Vout 90.8V CH2: Iout CH3: AC Vin Fig 13. Open Load Protection at 115V AC CH1: Vout 93.2V CH3: AC Vin CH2: Iout Fig 14. Open Load Protection at 265V AC 13 / 20 AN0389E

14 Protection (3): Short Load after AC Power Turn-on CH2: Iout CH1: Vout CH3: AC Vin Fig 15. Short Load Protection at 115V AC CH2: Iout CH3: AC Vin CH1: Vout Fig 16. Short Load Protection at 230V AC 14 / 20 AN0389E

15 Protection (4): Short Load before AC Power Turn-on, then cancel Short Load CH2: Iout CH3: AC Vin CH1: Vout Fig 17. Short Load Protection at 115V AC CH2: Iout CH3: AC Vin CH1: Vout Fig 18. Short Load Protection at 230V AC 15 / 20 AN0389E

16 Protection (5): Short Load before AC Power Turn-on CH2: Iout CH3: AC Vin CH1: Vout Fig 19. Short Load Protection at 115V AC CH3: AC Vin CH2: Iout CH1: Vout Fig 20. Short Load Protection at 230V AC 16 / 20 AN0389E

17 System Performance Efficiency (%) S, 145mA AC input (Vac) Fig 21. Efficiency vs. Wide AC Voltage Iout (ma) S, 145mA AC input (Vac) Fig 22. Iout Regulation vs. Wide AC Voltage Power Factor (PF) S, 145mA AC input (Vac) Fig 23. Power Factor (PF) vs. Wide AC Voltage 17 / 20 AN0389E

18 Iout (ma) Vac 100Vac 115Vac 135Vac Vac 220Vac 240Vac 265Vac S 20S 22S 24S 26S LED Series Fig 24. Iout Regulation vs. LED(s) Regulation Efficiency (%) LED 18S,145mA LED 22S,145mA LED 26S,145mA AC input (Vac) LED 20S,145mA LED 24S,145mA Fig 25. Efficiency vs. Wide AC Voltage (Different LED Series) Power Factor (PF) S (145mA) 20S (145mA) S (145mA) 26S (145mA) 24S (145mA) AC input (Vac) Fig 26. Power Factor (PF) vs. Wide AC Voltage (Different LED Series) 18 / 20 AN0389E

19 25 20 THD(%) LED 26S,145mA AC input (Vac) Fig 27. THD vs. Wide AC Voltage EMI: Test in E27 system level (26S1P) EMI _Radiatied Fig 28. EMI_VERTICAL Fig 29. EMI_HORIZONTAL 19 / 20 AN0389E

20 HT7L4813 E27/12W 26S 145mA LED Bulb EMI _Conduction Fig 30. EMI_LINE Fig 31. EMI_NEUTRAL 20 / 20 AN0389E