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LT3215 Dataheets PDF



Part Number LT3215
Manufacturers Linear Technology
Logo Linear Technology
Description 700mA Low Noise High Current LED Charge Pump
Datasheet LT3215 DatasheetLT3215 Datasheet (PDF)

LTC3215 700mA Low Noise High Current LED Charge Pump FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO High Efficiency Operation: 1x, 1.5x or 2x Boost Modes with Automatic Mode Switching Ultralow Dropout ILED Current Control Output Current up to 700mA Low Noise Constant Frequency Operation* Wide VIN Range: 2.9V to 4.4V Open/Shorted LED Protection LED Disconnect in Shutdown Low Shutdown Current: 2.5µA 4% LED Current Programming Accuracy Automatic Soft-Start Limits Inrush Current No Inductors Tiny .

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LTC3215 700mA Low Noise High Current LED Charge Pump FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO High Efficiency Operation: 1x, 1.5x or 2x Boost Modes with Automatic Mode Switching Ultralow Dropout ILED Current Control Output Current up to 700mA Low Noise Constant Frequency Operation* Wide VIN Range: 2.9V to 4.4V Open/Shorted LED Protection LED Disconnect in Shutdown Low Shutdown Current: 2.5µA 4% LED Current Programming Accuracy Automatic Soft-Start Limits Inrush Current No Inductors Tiny Application Circuit (All Components <1mm Profile) 3mm × 3mm 10-Lead DFN Package The LTC®3215 is a low noise, high current charge pump DC/DC converter designed to power high current LEDs. The part includes an accurate programmable current source capable of driving loads up to 700mA from a 2.9V to 4.4V input. Low external parts count (two flying capacitors, one programming resistor and two bypass capacitors) makes the LTC3215 ideally suited for small, batterypowered applications. Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small external capacitors. LED current is programmed with an external resistor. The LED is disconnected from VIN during shutdown. An ultralow dropout current source maintains accurate LED current at very low ILED voltages. Automatic mode switching optimizes efficiency by monitoring the voltage across the LED current source and switching modes only when ILED dropout is detected. The LTC3215 is available in a low profile 3mm × 3mm 10-Lead DFN package. , LTC and LT are registered trademarks of Linear Technology Corporation. *Protected by U.S. Patent 6411531. U APPLICATIO S ■ ■ LED Torch/Camera Light Supply for Cell Phones, PDAs and Digital Cameras General Lighting and/or Flash/Strobe Applications TYPICAL APPLICATIO C1 2.2µF C2 2.2µF 100 90 EFFICIENCY (PLED/PIN) (%) ILED = 200mA C1+ 2.9V TO 4.4V CIN 2.2µF VIN C1– C2+ C2– CPO LED1 CCPO 4.7µF 80 70 60 50 40 30 20 10 LTC3215 ILED ILED 200mA DISABLE ENABLE EN ISET 20k 1% 3215 TA01a LED = AOT2015 HPW 1751B VF = 3V TYP AT 200mA 2.8 3.0 3.2 3.4 3.6 3.8 VIN (V) 4.0 4.2 4.4 0 LED1: AOT2015 HPW 1751B U Efficiency vs VIN 3215 TA01b U 3215f 1 LTC3215 ABSOLUTE (Note 1) AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO TOP VIEW C2+ C1+ CPO ILED ISET 1 2 3 4 5 11 10 C1– 9 GND 8 C2– 7 VIN 6 EN VIN to GND ............................................... –0.3V to 5.5V CPO to GND ............................................. –0.3V to 5.5V EN ................................................... –0.3V to VIN + 0.3V ICPO, IILED (Note 2) ........................................... 1000mA CPO Short-Circuit Duration ............................ Indefinite Storage Temperature Range ................. –65°C to 125°C Operating Temperature Range (Note 3) .. –40°C to 85°C The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, CIN = C1 = C2 = 2.2µF, CCPO = 4.7µF. PARAMETER Input Power Supply VIN Operating Voltage IVIN Operating Current ICPO = 0mA, 1x Mode ICPO = 0mA, 1.5x ICPO = 0mA, 2x Mode EN = LOW ILED = 200mA to 600mA Mode Switch Threshold, ILED = 200mA EN to LED Current On ICPO = 0mA ICPO = 0mA ICPO = 0mA VIN = 3.4V, VCPO < 4.6V, C1 = C2 = 2.2µF VIN = 3.2V, VCPO < 5.1V, C1 = C2 = 2.2µF ● ● ● ● ● ● ● ELECTRICAL CHARACTERISTICS IVIN Shutdown Current LED Current LED Current Ratio (ILED/ISET) ILED Dropout Voltage Mode Switching Delay (LED Warmup Time) LED Current On Time Charge Pump (CPO) 1x Mode Output Voltage 1.5x Mode Output Voltage 2x Mode Output Voltage 1x Mode Output Impedance 1.5x Mode Output Impedance 2x Mode Output Impedance CLK Frequency EN High Level Input Voltage (VIH) Low Level Input Voltage (VIL) Input Current (IIH) Input Current (IIL) 2 U W W W ORDER PART NUMBER LTC3215EDD DD PART MARKING LBPX DD PACKAGE 10-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 43°C/W EXPOSED PIN (PIN 11) IS GND MUST BE SOLDERED TO PCB Consult LTC Marketing for parts specified with wider operating temperature ranges. CONDITIONS MIN 2.9 TYP MAX 4.4 UNITS V µA mA mA 300 7 9.2 2.5 3139 3270 120 2.5 130 VIN 4.6 5.1 0.25 1.5 1.7 0.6 1.4 0.4 –1 –1 1 1 0.9 1.2 7 3400 µA mA/mA mV ms µs V V V Ω Ω Ω MHz V V µA µA 3215f LTC3215 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, CIN = C1 = C2 = 2.2µF, CCPO = 4.7µF. PARAMETER ISET VISET IISET Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Based on long-term current density limitations. Assumes an operating duty cycle of ≤ 10% under absolute maximum conditions for durations less than 10 seconds. Max current for continuous operation is 350mA. ISET = 50µA ● ● ELECTRICAL CHARACTERISTICS CONDITIONS MIN 1.195 TYP 1.22 MAX 1.245 225 UNITS V µA Note 3: The LTC3215E is guaranteed to meet performance spec.


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