LTC3218 - 400mA Single Wire Camera LED Charge Pump

Features

  • Low Noise Constant-Frequency Operation
  • Multi-Mode Operation: 1x or 2x Boost Mode
  • Automatic Mode Switching
  • High Output Current: 150mA (Continuous), 400mA (Pulsed) From Li-Ion/Polymer Input
  • 2-Second Flash Current Timeout for LED Protection
  • Automatic Soft-Start
  • Output Disconnect
  • No Inductors
  • 220mΩ Internal High Side Current Sense Resistor
  • Single Resistor Programming Capability
  • Tiny Application Circuit (3mm × 2mm DFN Package, All Components < 1mm High)

Typical Application

LTC3218 Typical Application
LTC3218 Typical Application

Description

The LTC3218 is a low-noise, high-current charge pump DC/DC converter capable of driving high current LEDs at up to 400mA from a 2.9V to 4.5V input. A low external parts count (one flying capacitor, two programming resistors and two bypass capacitors at VIN and CPO) make the LTC3218 ideally suited for small, battery-powered applications.

Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small external capacitors. A built-in 2-second timer protects the LED during flash mode.

Output current level is programmed by an external resistor. LED current is regulated using an internal high side 220mΩ sense resistor. Automatic mode switching optimizes efficiency by monitoring the voltage across the charge pump and switching modes only when dropout is detected. The part is available in a low profile 3mm × 2mm 10-lead DFN package.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC3218EDDB#PBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3218EDDB#TRMPBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3218EDDB#TRPBF 3x2 DFN-10 DDB E 05-08-1722 Yes


LTC3218 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3218EDDB#PBF 3x2 DFN-10 E $2.06 Yes
LTC3218EDDB#TRMPBF 3x2 DFN-10 E $2.06 $1.49 Yes
LTC3218EDDB#TRPBF 3x2 DFN-10 E $2.06 $1.44 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1030A LTC3218EDDB Demo Board | Boost Charge Pump Camera LED Driver, 2.9V ≤ VIN ≤ 4.5V, VLED up to 4.5V @ 400mA Contact Factory
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Click here to view our complete list of demo boards

Applications

  • LED Torch/Flash Supply for DSCs/Cellphones

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC3218

Technical Support