Description
Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3386 DESCRIPTION The KB3386 is a current regulated charge pump ideal for powering high brightness LEDs for camera flash applications. The charge pump can be set to regulate two current levels for FLASH and TORCH modes. The KB3386 automatically switches modes between step-up and step-down ensuring that LED current does not depend on the forward voltage. A low current sense reference voltage (50mV) allows the use of small 0603 current sensing resistors. The KB3386 is . offered in 10-pin DFN package. 400mA Buck/Boost Charge Pump LED Driver FEATURES ■ Output Current up to 400mA ■ Up to 94% Efficiency in Torch Mode ■ Automatic Softstart Limits Inrush Current ■ Adjustable FLASH Mode ■ x1 and x2 Automatic Modes for High Efficiency www.DataSheet4U.com ■ Minimum External Components: No Inductors ■ High Frequency Operation: 2.4 MHz ■ Low 50mV Reference for low Loss Sensing ■ 1 A Shutdown Current ■ PWM Dimming Control ■ Automatic Switchover Between Buck/Boost ■ Overvoltage Protection on Output ■ Overcurrent/Temerature Protection ■ Low Ripple and EMI ■ Space Saving 10-pin 3mm x 3mm DFN Package VIN 1 2 3 4 5 10 VOUT PGND SGND IFB ISET APPLICATIONS ■ White LED Torch/Flash for Cell Phones, DSCs, and Camcorders ■ Generic Lighting/Flash/Strobe Applications ■ White LED Backlighting C1 C2 FLASH EN KB3386 10 Pin DFN 9 8 7 6 Now Available in Lead Free Packaging APPLICATION CIRCUIT VIN (2.7 - 5.5V) 1 CIN 2.2 F VIN C1 C2 FLASH EN VOUT KB3386 PGND SGND FB RSET 10 9 8 7 6 400mA FLASH COUT 1F WLED FB=150mV CFC 0.47 F TORCH/FLASH ENABLE 2 3 4 5 RSET 106K RSENSE 0.33 1 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3386 TOP Marking XXXX 400mA Buck/Boost Charge Pump LED Driver PIN CONFIGURATION TOP VIEW PGND SGND VOUT 9 8 7 10 6 ISET IFB www.DataSheet4U.com 1 2 3 4 5 86ER yyyy VIN FLASH EN C1 C2 ORDER INFORMATION Part number Package XXXX: LOT number yyyy: Data code : Pin 1 Marking KB3386ER DFN-10,GREEN 86ER PIN DESCRIPTION PIN NUMBER 1 2 3 4 PIN NAME VIN C1 C2 FLASH DESCRIPTION Input Voltage for the charge pump. Decouple with 2.2 F ceramic capacitor close to the pins of the IC. Positive input for the external fly capacitor. Connect a ceramic 0.47 F capacitor close to the pins of the IC. Negative input for the external fly capacitor. Connect a ceramic 0.47 F capacitor close to the pins of the IC. Logic input to toggle operation between FLASH and TORCH mode. In TORCH mode FB is regulated to the internal 50mV reference. In FLASH mode FB reference voltage can be adjusted by changing the resistor from RSET pin to ground. Choose the external current sense resistor (RSENSE) based on desired current in TORCH mode. Shutdown control input. Connect to VIN for normal operation, connect to ground for shutdown. Connect a resistor from this pin to ground. When in FLASH mode (FLASH = High) this resistor sets the current regulation point according to the following: VFB = (1.26V/ RSET)*11.2K . Feedback input for the current control loop. Connect directly to the current sense resistor. Internal ground pin. Control circuitry returns current to this pin. Power ground pin. Fly capacitor current returns through this pin. Charge Pump Output Voltage. Decouple with an external capacitor. At least 1uF is recommended. Higher capacitor values reduce output ripple. 5 6 EN RSET 7 8 9 10 FB SGND PGND VOUT 2 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3386 0 400mA Buck/Boost Charge Pump LED Driver ABSOLUTE MAXIMUM RATINGS VIN , VOUT ...................................................................... -0.3V to 6V Output Current Pulse (Flash) .......................... 500mA Output Current Continuous (Torch) ................. 200mA Storage Temperature ...................... -65°C to +150°C Operating Temperature ..................... -40°C to +85°C VEN ......................................................... ZeroV to 7V www.DataSheet4U.com 10 DFN .........................................O = 57.1°C/W 3x3 JA ESD Rating. ................................................ 2kV HBM (Ta=+250C) ELECTRICAL CHARACTERISTICS (Ta=+25 C) 0 TA = -40°C to +85°C, VIN = 3.6, CIN = 2.2 F, CFC = 0.47 F, COUT = 1.0 F. VSHDN = VIN, typical values at 25°C. The denotes the specifications which apply over the full operating range unless otherwise noted. PARAMETER Operating Input Voltage Quiescent Current MIN. 2.7 TYP. MAX. 5.5 UNITS V mA CONDITIONS 0.5 2 3 V IN = 2.7 - 5.5V FLASH = 0Volts, Iload = 100µA FLASH = VIN, 2x mode Shutdown Current Oscillator Frequency Charge Pump Equivalent Resistance (x2 mode) Charge Pump Equivalent Resistance (x1 mode) FB Reference Voltage FB Reference Voltage FB Pin Current EN, FLASH Logic Low EN, FLASH Logic High EN, FLASH Pin Current V OUT Turn-on Time Thermal Shutdown Temperature 250 145 1.3 138 45 2.4 5 0.6 150 50 1 µA MHz V IN = 5.5V, VEN = 0Volts V FB = 0Volts, VIN= 3.6V 0.8 162 55 0.5 0.4 mV mV µA V V 0.5 500 µA µs ºC V IN = 3.6V, FB within 90% of regulation V IN= 3.6V FLASH = VIN R SET = 106K FLASH = GND V FB = 0.3V 3 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3386 D1 = AOT 2015HPW-1915B LED. Flash Mode 400mA Iout 400mA Buck/Boost Charge Pump LED Driver TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6, Typical Application, TA = 25°C unless otherwise noted. Torch Mode 150mA Iout 250 200 600 500 (mA) 400 150 IOUT (mA) 300 200 100 0 3.0 www.DataSheet4U.com100 50 0 3.0 Iout Vf = 3.5V Vf = 3.3V Vf = 3.1V Vf = 3.0V 3.2 3.4 3.6 Vin (V) 3.8 4.0 4.2 Vf = 4.1V Vf = 3.8V Vf = 3.5V Vf = 3.2V 3.2 3.4 3.6 VIN (V) 3.8 4.0 4.2 Figure 1. Output Current vs. Supply Voltage (CIN = 2.2 F, CFC = 0.47 F, COUT = 1.0 F Figure 2. Output Current vs. Supply Voltage (CIN = 2.2 F, CFC = 0.47 F, COUT = 1.0 F Torch Mode 150mA Efficie 100 100 90 80 70 60 50 40 3.0 Flash Mode 400mA Efficie Vf = 4.1V Efficiency (%) Efficiency (%) 90 80 Vf = 3.8V Vf = 3.5V Vf = 3.2V Vf = 3.5V 70 60 50 40 3.0 Vf = 3.3V Vf = 3.1V Vf = 3.0V 3.2 3.4 3.6 Vin (V 3.8 4.0 4.2 3.2 3.4 3.6 Vin (V 3.8 4.0 4.2 Figure 3. Efficiency vs. Supply Voltage (CIN = 2.2 F, CFC = 0.47 F, COUT = 1.0 F) Figure 4. Efficiency vs. Supply Voltage (CIN = 2.2 F, CFC = 0.47 F, COUT = 1.0 F) Recommended PCB Layout 4 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3386 400mA Buck/Boost Charge Pump LED Driver FUNCTIONAL DIAGRAM RSET BLOCK RSET 6 CLK RSET REF BG REF + - 1.26V RESISTOR TAPS www.DataSheet4U.com + RSET 1.26V V= RSET MUX 2x1 50mV 0 s 1 FB REF + FB 7 SGN 8 FB COM P COUNTER 32 COUNT FB COMP CLR SET DOMINANT S 0 R { }x11. 2kohms ONE SHOT FLASH 4 FLASH=1, S=1, RSET REF FLASH=0, S=0, 50mV EN 5 VIN 1 MODE SWITCH 0 =1X 1=2X 135C ON 145C OFF THERMAL FAULT OVER TEMP COMP CHARGE PUMP SWITCHES C1 C2 VOUT 2.4MHZ CLK CLK PGND THEORY OF OPERATION The KB3386 is a charge pump regulator designed for converting a Li-Ion battery voltage of 2.7V to 4.2V to drive a white LED used in digital still camera Flash and Torch applications. The KB3386 has two modes of operation which are pin selectable for either Flash or Torch. Flash mode is usually used with a pulse of about 200 to 300 milliseconds to generate a high intensity Flash. Torch can be used continuously at a lower output current than Flash and is often used for several seconds in a digital still camera “movie” mode. The KB3386 also has two modes of operation to control the output current, the 1X mode and 2X mode. Operation begins after the enable pin EN receives a logic high, the bandgap reference wakes up after 200 sec, and then KB3386 goes through a soft-start mode designed to reduce inrush current. The KB3386 starts in the 1X mode, which acts like a linear regulator to control the output current by continuously monitoring the feedback pin FB. In 1X mode, if the KB3386 auto detects a dropout condition, which is when the FB pin is below the 5 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3386 400mA Buck/Boost Charge Pump LED Driver APPLICATION INFORMATION regulation point for more than 32 cycles of the internal clock, the KB3386 automatically switches to the 2X mode. The KB3386 remains in the 2X mode until one of four things happens: 1) the enable pin EN has been toggled, 2) the Flash pin has changed www.DataSheet4U.com from high to low, 3) V is cycled or 4) a IN thermal fault occurs. The 2X mode is the charge pump mode where the output can be pumped as high as two times the input voltage, provided the output does not exceed the maximum voltage for the KB3386, which is internally limited to about 5.5V. In the 2X mode, as in the 1X mode, the output current is regulated by the voltage at the FB pin. In the Torch mode, (Flash = GND) the Flash pin is set to logic low and the KB3386 FB pin regulates to 50mV output: VFB = 50mV (Torch Mode) When in Flash mode, (Flash = VIN), the FB regulation voltage is set by the resistor RSET connected between the RSET pin and SGND and the equation: VFB = (1.26V/ RSET)*11.2K (Flash Mode) _______________OVERTEMPERATURE PROTECTION When the temperature of the KB3386 rises above 145 degrees Celsius, the over temperature protection circuitry turns off the output switches to prevent damage to the device. If the temperature drops back down below 135 degrees Celsius, the part automatically recovers and executes a soft start cycle. ____________________OVERVOLTAGE PROTECTION The KB3386 has over voltage protection. If the output voltage rises above the 5.5V threshold, the over voltage protection shuts off all of the output switches to prevent the output voltage from rising further. When the output decreases below 5.5V, the device resumes normal operation ____________________OVERCURRENT PROTECTION The over current protection circuitry monitors the average current out of the VOUT = 50mV (T

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