DatasheetsPDF.com

LT3466EDD Dataheets PDF



Part Number LT3466EDD
Manufacturers Linear
Logo Linear
Description Dual Full Function White LED Step-Up Converter
Datasheet LT3466EDD DatasheetLT3466EDD Datasheet (PDF)

U U FEATURES ■ Drives Up to 20 White LEDs (10 in Series per Converter) from a 3.6V Supply ■ Two Independent Step-Up Converters Capable of Driving Asymmetric LED Strings ■ Independent Dimming and Shutdown Control of the Two LED Strings ■ Internal Schottky Diodes ■ Internal Soft-Start Eliminates Inrush Current ■ Open LED Protection (39.5V Max VOUT) ■ Fixed Frequency Operation Up to 2MHz ■ 81% Efficiency Driving 16 White LEDs at 15mA (Eight per Driver) from a 3.6V Supply ■ Wide Input Voltage Range.

  LT3466EDD   LT3466EDD


Document
U U FEATURES ■ Drives Up to 20 White LEDs (10 in Series per Converter) from a 3.6V Supply ■ Two Independent Step-Up Converters Capable of Driving Asymmetric LED Strings ■ Independent Dimming and Shutdown Control of the Two LED Strings ■ Internal Schottky Diodes ■ Internal Soft-Start Eliminates Inrush Current ■ Open LED Protection (39.5V Max VOUT) ■ Fixed Frequency Operation Up to 2MHz ■ 81% Efficiency Driving 16 White LEDs at 15mA (Eight per Driver) from a 3.6V Supply ■ Wide Input Voltage Range: 2.7V to 24V ■ Available in 10-Pin DFN and 16-Pin Thermally Enhanced TSSOP Packages U APPLICATIO S ■ Main/Sub Displays ■ Digital Cameras, Sub-Notebook PCs ■ PDAs, Handheld Computers ■ Automotive LT3466 Dual Full Function White LED Step-Up Converter with Built-In Schottky Diodes DESCRIPTIO LT®3466 is a dual full function step-up DC/DC converter specifically designed to drive up to 20 White LEDs (10 in series per converter) with a constant current. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors and expensive factory calibration. The two independent converters are capable of driving asymmetric LED strings. The dimming of the two LED strings can also be controlled independently. The LT3466 is ideal for providing backlight for main and sub-displays in cell phones and other handheld devices. The LT3466 operating frequency can be set with an external resistor over a 200kHz to 2MHz range. A low 200mV feedback voltage minimizes power loss in the current setting resistor for better efficiency. Additional features include output voltage limiting when LEDs are disconnected and internal soft-start. The LT3466 is available in the 10-pin (3mm × 3mm × 0.75mm) DFN and 16-pin thermally enhanced TSSOP packages. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO 3V TO 5V 1µF L1 47µH L2 47µH LED1 2.2µF SW1 VIN VOUT1 SW2 VOUT2 LT3466 2.2µF LED2 FB1 FB2 CTRL1 RT GND CTRL2 10Ω OFF ON 63.4k SHUTDOWN AND DIMMING CONTROL 1 OFF ON SHUTDOWN AND DIMMING CONTROL 2 10Ω 3466 F01a Figure 1. Li-Ion Powered Driver for 8/8 White LEDs EFFICIENCY (%) Conversion Efficiency 85 VIN = 3.6V 8/8 LEDs 80 75 70 65 60 55 50 0 5 10 15 LED CURRENT (mA) 20 3466 F01b 3466fa 1 LT3466 U WW W ABSOLUTE AXI U RATI GS (Note 1) Input Voltage (VIN) ................................................... 24V SW1, SW2 Voltages ................................................ 44V VOUT1, VOUT2 Voltages ............................................. 44V CTRL1, CTRL2 Voltages ........................................... 24V FB1, FB2, RT Voltages ................................................ 2V Operating Temperature Range (Note 2) ... –40°C to 85°C Maximum Junction Temperature ......................... 125°C Storage Temperature Range DFN .................................................. –65°C to 125°C TSSOP .............................................. –65°C to 150°C Lead Temperature (Soldering, 10 sec, TSSOP) ..... 300°C UW U PACKAGE/ORDER I FOR ATIO TOP VIEW VOUT1 1 SW1 2 VIN 3 SW2 4 VOUT2 5 10 FB1 9 CTRL1 11 8 RT 7 CTRL2 6 FB2 DD PACKAGE 10-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 43°C/W, θJC = 2.96°C/W EXPOSED PAD (PIN 11) IS GND MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3466EDD DD PART MARKING LBBH Consult LTC Marketing for parts specified with wider operating temperature ranges. TOP VIEW GND 1 NC 2 VOUT1 3 SW1 4 VIN 5 SW2 6 VOUT2 7 GND 8 16 GND 15 FB1 14 CTRL1 13 NC 17 12 RT 11 CTRL2 10 FB2 9 GND FE PACKAGE 16-LEAD PLASTIC TSSOP TJMAX = 125°C, θJA = 38°C/W, θJC(PAD) = 10°C/W EXPOSED PAD (PIN 17) IS GND MUST BE SOLDERED TO PCB ORDER PART NUMBER LT3466EFE FE PART MARKING 3466EFE ELECTRICAL CHARACTERISTICS The ● denotes specifications that apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3V, VCTRL1 = 3V, VCTRL2 = 3V, unless otherwise specified. PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Operating Voltage 2.7 V Maximum Operating Voltage 24 V FB1 Voltage ● 192 200 208 mV FB2 Voltage ● 192 200 208 mV Offset Voltage (VOS) Between FB1 and FB2 Voltages FB1 Pin Bias Current FB2 Pin Bias Current Quiescent Current VOS = |FB1 – FB2| VFB1 = 0.2V (Note 3) VFB2 = 0.2V (Note 3) VFB1 = VFB2 = 0.3V CTRL1 = CTRL2 = 0V 0 1.5 7.5 mV 10 50 nA 10 50 nA 5 7.5 mA 16 25 µA Switching Frequency Oscillator Frequency Range RT = 48.7k (Note 4) 0.8 1 1.2 MHz 200 2000 kHz Nominal RT Pin Voltage Maximum Duty Cycle RT = 48.7k RT = 48.7k RT = 20.5k RT = 267k 0.54 V ● 90 96 % 92 % 99 % 3466fa 2 LT3466 ELECTRICAL CHARACTERISTICS The ● denotes specifications that apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3V, VCTRL1 = 3V, VCTRL2 = 3V, unless otherwise specified. PARAMET.


LTC3424 LT3466EDD LT3466EFE


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)