BW7385 Non-isolation Buck current control IC with High PFC for LED Lighting Description The BW7385 is a THD and Efficiency adjustable, high accuracy and high power factor constant current PWM controller. This is capable of controlling THD and Efficiency optimization by an external resistor. These functions enable the LED driver to easily meet rule of LED current requirements The IC achieves high power factor and high efficiency by Packing & Order Information BCM mode. The line and load regulation of LED current 3,000/Reel is about ±2.5% because of particular control method. BW7385 also provides gate driving voltage clamping, Pin Configurations (Top View) VCC over voltage protection and system output open/short circuit protection to increase IC performance. Features • THD and Efficiency adjustable by RT Pin • Low THD <15% (ADJ) • Accuracy Constant Current (±2.5%) • High power factor (>0.9) • Low BOM Cost Applications • Boundary Current Mode Control • LED lighting • Gate Output Voltage Clamp • Down light • LED Open Protection(OVP) • Tube lamp • LED Short Protection(SCP) • PAR lamp • Over Current Protection (OCP) • Bulb • Over Thermal Protection(OTP) • SOT26 Package Available • RoHS compliant package PIN DESCRIPTIONS Pin Name Pin Description VCC Power supply pin for all internal circuit GND Ground return for all internal circuit OUT Gate driver output RT Efficiency / THD option pin COM Output pin of error amplifier CS Input current sense pin Publication Order Number: [BW7385] © Bruckewell Technology Corporation Rev. A -2014 BW7385 Non-isolation Buck current control IC with High PFC for LED Lighting TYPICAL APPLICATION CIRCUITS ABSOLUTE MAXIMUM RATINGS (Note 1) Parameter Symbol Range Unit Power supply pin VCC 40 V RT voltage to GND VRT -0.3 to 5.5 V CS voltage to GND VCS -0.3 to 5.5 V OUT voltage to GND VOUT -0.3 to 40 V COM voltage to GND VCOM -0.3 to 5.5 V TJ -40 to +150 °C Storage temperature rang TSTG -65 to +150 °C Lead temperature (Soldering 10 sec) TLEAD 260 °C Power dissipation @TA=25°C PD 0.3 W Thermal resistance junction to ambient (Note 2) θJA 220 °C/W Thermal Resistance θJC 106.6 °C/W ESD rating, Human body mode (Note 3) VESD 2 kV ESD rating, machine mode (Note 3) VESD 200 V Maximum junction temperature Publication Order Number: [BW7385] © Bruckewell Technology Corporation Rev. A -2014 BW7385 Non-isolation Buck current control IC with High PFC for LED Lighting RECOMMENDED OPERATING CONDITIONS (Note 4) Parameter Symbol Operation Conditions Unit Power supply pin VCC 33 V RT voltage to GND VRT -0.3 to 5 V CS voltage to GND VCS -0.3 to 5 V OUT voltage to GND VOUT -0.3 to 19 V COM voltage to GND VCOM -0.3 to 5 V Operating Junction Temperature Range TJ -40 to +125 °C Operating Ambient Temperature Range TOPA -40 to +85 °C Note 1: Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2: Thermal Resistance is specified with the component mounted on a low effective thermal conductivity test board in free air at TA=25°C. Note 3: Devices are ESD sensitive. Handing precaution recommended. Note 4: The device is not guaranteed to function outside its operating conditions. BLOCK DIAGRAM Publication Order Number: [BW7385] © Bruckewell Technology Corporation Rev. A -2014 BW7385 Non-isolation Buck current control IC with High PFC for LED Lighting ELECTRICAL CHARACTERISTICS VCC=15V, TA= 25°C, unless otherwise specified. SUPPLY VOLTAGE Parameter Symbol Conditions Startup Current VCC(ST) VCC= VUVLO(on) -1V 45 Operating Current IOPA With 1nF load on OUT pin 2.1 2.6 mA UVLO(off) VUVLO(off) 7 8 9 V UVLO(on) VUVLO(on) 16 17.5 19 V OVP Level on VCC Pin VOVP 29 31 33 V Min Typ. Max. Units 0.196 0.2 0.204 V Min Typ. Max. Units uA VOLTAGE FEEDBACK Parameter Symbol Feedback Reference Voltage VFB Tran-Conductance GM 58 uS Output Sink Current Io-sink 5.8 uA Output Source Current Io-source 5.8 uA Conditions CURRENT SENSING Parameter Symbol CS limit Voltage VOCP 1.4 V Open Loop Voltage, CS Pin Open VOLP 5 V Leading-Edge Blanking Time LEB 400 nS 100 nS Conditions Min Delay to Output SWITCHING FREQUENCY Parameter Symbol Start Frequency TSTR Conditions Typ. Max. Units Min Typ. Max. KHz 3 4.5 6 KHz Min Typ. Max. Units GATE DRIVER OUTPUT Parameter Symbol Conditions Rising Time TRISE Load Capacitance = 1000pF 90 nS Falling Time TFAIL Load Capacitance = 1000pF 40 nS VGATE-Clamp VGATE Thermal Section Parameter Symbol Conditions Min 12.5 15 V Typ. Max. Units Thermal Shutdown 150 °C Thermal Shutdown release 120 °C Publication Order Number: [BW7385] © Bruckewell Technology Corporation Rev. A -2014 BW7385 Non-isolation Buck current control IC with High PFC for LED Lighting APPLICATION INFORMATION OCP(Over Current Protection) Start-up Current The BW7385 is built cycle by cycle over current protection The typical start-up current is around 45uA. Very low start-up function on CS pin. As the CS pin voltage is larger than VOCP current allows the PWM controller to increase the value of (1.4V), the gate output will be turned off immediately to avoid the start-up resistor and then reduce the power dissipation on it. driver board be burned out. UVLO(Under Voltage Lockout) OVP (Over Voltage Protection) on VCC A hysteresis UVLO comparator is implemented in BW7385 then The prevent the LED driver from being damaged, the BW7386 the turn-on an turn-off thresholds level are fixed at 17.5V and 8V is implemented an OVP function on VCC. When the VCC respectively. This hysteresis shown in Fig.3 ensures that the voltage is higher than the OVP threshold voltage 31V, the output start-up capacitor will be adequate to supply the chip during gate driver circuit will be shut down immediately to stop the start-up. For quickly startup the LED driver, the start-up resistor switching of power MOSFET. The VCC pin OVP function is an should be matched with the startup capacitor. Due to the low auto recovery type protection (latch off type optional). If the OVP UVLO on level, so the turn-on delay time will also never greater condition happens, the pulses will be stopped and never than the general PWM IC. recovery unless the VCC pin voltage is down to the UVLO off level. The BW7385 is working in an auto-recovery mode as shown in Fig. 4. LEB(Leading-Edge Blanking) Each time the power MOSFET is switched on, a turn-on spike will inevitably occur at the sense resistor. To avoid fault trigger, a 400ns leading-edge blanking time is built in. Conventional RC filtering can therefore be omitted. During this blanking period, the current-limit comparator is disabled and can not switch off the Gate Clamp gate driver. Driver is clamped to 12.5V by an internal clamping circuit to avoid the Gate of MOSFET be damage. Publication Order Number: [BW7385] © Bruckewell Technology Corporation Rev. A -2014 BW7385 Non-isolation Buck current control IC with High PFC for LED Lighting Disclaimer ALL PRODUCT, PRODUCT SPECIFICATIONS AND DATA ARE SUBJECT TO CHANGE WITHOUT NOTICE TO IMPROVE RELIABILITY, FUNCTION OR DESIGN OR OTHERWISE. Bruckewell Technology Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively, “Bruckewell”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained in any datasheet or in any other disclosure relating to any product. Bruckewell makes no warranty, representation or guarantee regarding the suitability of the products for any particular purpose or the continuing production of any product. To the maximum extent permitted by applicable law, Bruckewell disclaims (i) Any and all liability arising out of the application or use of any product. (ii) Any and all liability, including without limitation special, consequential or incidental damages. (iii) Any and all implied warranties, including warranties of fitness for particular purpose, non-infringement and merchantability. Statements regarding the suitability of products for certain types of applications are based on Bruckewell’s knowledge of typical requirements that are often placed on Bruckewell products in generic applications. Such statements are not binding statements about the suitability of products for a particular application. It is the customer’s responsibility to validate that a particular product with the properties described in the product specification is suitable for use in a particular application. Parameters provided in datasheets and/or specifications may vary in different applications and performance may vary over time. Product specifications do not expand or otherwise modify Bruckewell’s terms and conditions of purchase, including but not limited to the warranty expressed therei Publication Order Number: [BW7385] © Bruckewell Technology Corporation Rev. A -2014