Power Management Switching Regulator Step-Up (Boost) Regulators Internal Power Switch Boost

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LTC1517-5 - Micropower, Regulated 5V Charge Pump in a 5-Pin SOT-23 Package

LTC6246 - 180MHz, 1mA Power Efficient Single Rail-to-Rail I/O Op Amps
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LTC1340 - Low Noise, Voltage-Boosted Varactor Driver

Features

  • OBSOLETE:  For Information Purposes Only.  Contact Linear Technology for Potential Replacement.
  • Generates 5V Varactor Drive from a 3V Supply
  • Wide Supply Voltage Range: 2.7V to 6V
  • Requires Only Three External Components
  • Micropower Operation: 400µA at 3V Supply
  • Shutdown Mode Drops Supply Current Below 1µA
  • Low Output Noise: 15µVRMS
  • Amplifier Gain: 2.3
  • Up to 500kHz Signal Bandwidth
  • MS8 and SO-8 Packages
  • Very Low Input Bias Current: 10nA Max
  • Amplifier Offset Maintains Phase Detector in Linear Region

Typical Application

LTC1340 Typical Application
LTC1340 Typical Application

Description

OBSOLETE:  For Information Purposes Only.  Contact Linear Technology for Potential Replacement.

The LTC1340 is a varactor diode driver designed to generate 5V varactor drive from a single 3V or higher voltage supply. It includes a low noise amplifier with an internal gain of 2.3 and a self-contained charge pump to generate output voltages above the input supply. The amplifier input stage includes a built-in offset voltage that allows the output voltage to swing to ground without requiring OV on the input. This feature maintains the phase detector within its linear range of operation. The LTC1340 requires only three external surface mount capacitors to implement a complete varactor driver module.

The LTC1340 features output referred noise of 15µVRMS, minimizing frequency deviation in PLL frequency synthesizer systems. Supply current is 400µA typically with a 3V supply, and drops to 1µA in shutdown, maximizing operating life in battery-powered systems. Amplifier bandwidth is user-adjustable from 10kHz up to 500kHz and the output typically sinks or sources 20µA, allowing fast output signal changes with a typical varactor load. The amplifier input features rail-to-rail input common mode range, allowing it to interface with the output of virtually any phase detector circuit.

The LTC1340 is available in MS8 and SO-8 packages.

Packaging

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

LTC1340 Package Drawing
LTC1340 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

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.

Click here to view our complete list of demo boards

Applications

  • 5V Varactor Drive from a Single Li-Ion Cell
  • 5V Varactor Drive from Three NiCd/NiMH Cells
  • Cellular Telephones
  • Portable RF Equipment
  • Radio Modems
  • Wireless Data Transmission

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
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