LINEAR TECHNOLOGY LTC3215 User's Manual
Summary
The LTC3215 is an advanced, low-noise DC/DC charge pump designed for efficiently powering high-current LEDs up to 700mA. It features automatic mode switching (1x, 1.5x, or 2x boost) within a wide voltage range (2.9V to 4.4V), critical for battery-powered devices. This manual provides comprehensive technical details on its operating characteristics, including ultralow dropout control, LED protection circuits, and soft-start management. It is ideally suited for portable applications such as camera flash units, handheld lighting systems, PDAs, and general battery-operated strobe/torch functions.
Page 1 Text Content
LTC3215
700m A Low Noise High Current LED Charge Pump
FEATURES DESCRIPTIO High Efficiency Operation: 1x, 1.5x or 2x Boost The LTC®3215 is a low noise, high current charge pump Modes with Automatic Mode Switching DC/DC converter designed to power high current LEDs.
Ultralow Dropout ILED Current Control The part includes an accurate programmable current
Output Current up to 700m A source capable of driving loads up to 700m A from a 2.9V
Low Noise Constant Frequency Operation* to 4.4V input. Low external parts count (two flying capaci- Wide VIN Range: 2.9V to 4.4V tors, one programming resistor and two bypass capaci- Open/Shorted LED Protection tors) makes the LTC3215 ideally suited for small, battery- LED Disconnect in Shutdown powered applications.
Low Shutdown Current: 2.5µA
Built-in soft-start circuitry prevents excessive inrush cur-
4% LED Current Programming Accuracy
rent during start-up. High switching frequency enables the
Automatic Soft-Start Limits Inrush Current
use of small external capacitors. LED current is pro-
No Inductors
grammed with an external resistor. The LED is discon-
Tiny Application Circuit (All Components <1mm
nected from VIN during shutdown.
Profile)
EF FI CI EN CY (P LE D/ N)
3mm × 3mm 10-Lead DFN Package An ultralow dropout current source maintains accurate LED current at very low ILED voltages. Automatic mode switching optimizes efficiency by monitoring the voltage
APPLICATIO S
across the LED current source and switching modes only
LED Torch/Camera Light Supply for Cell Phones, when ILED dropout is detected. The LTC3215 is available in PDAs and Digital Cameras a low profile 3mm × 3mm 10-Lead DFN package. General Lighting and/or Flash/Strobe Applications
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Protected by U.S. Patents including 6411531.
TYPICAL APPLICATIO
Efficiency vs VIN
ILED = 200m A
C1+ C1– C2+ C2– VIN2.9V TO 4.4V CPO
CIN LED1 CCPO
2.2µF LTC3215 4.7µF
ILED ILED
ENDISABLE ENABLE
LED = AOT2015 20k VF = 3V TYP AT 200m A
3215 TA01a
VIN (V)
LED1: AOT2015
3215 TA01b
3215fa
Page Summary Contents For LINEAR TECHNOLOGY LTC3215 User's Manual
Manual Details
| Brand | Linear |
|---|---|
| Pages | 12 |
| File Size | 187.82 KB |
| Published | June 18, 2026 |
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Frequently Asked Questions
What is the primary application of the LTC3215?
It is designed as a charge pump for high current LEDs, ideal for small, battery-powered applications like PDAs and digital cameras.
What is the maximum rated output current for the LED source?
The output current source is capable of driving loads up to 700mA.
Does this circuit require inductors or many external parts?
No. It features a low external parts count and does not utilize inductors.
What protection features are included in the device?
It includes Open/Shorted LED Protection, built-in soft-start circuitry to limit inrush current, and automatic mode switching.