Features and Benefits
- Very Low Noise: 1mVP–P Output Ripple
- –5V at 150mA from a 5V Input
- Better Regulation Than a Charge Pump
- Effective Output Impedance: 0.14Ω
- Uses Tiny Capacitors and Inductors
- Internally Compensated
- Fixed Frequency 1.4MHz Operation
- Low Shutdown Current: <1µA
- Low VCESAT Switch: 300mV at 300mA
- Tiny 5-Lead SOT-23 Package
The LT1611 is the industry’s first inverting 5-lead SOT-23 current mode DC/DC converter. Intended for use in small, low power applications, it operates from an input voltage as low as 1.1V and switches at 1.4MHz, allowing the use of tiny, low cost capacitors and inductors 2mm or less in height. Its small size and high switching frequency enable the complete DC/DC converter function to consume less than 0.25 square inches of PC board area. Capable of generating –5V at 150mA from a 5V supply or –5V at 100mA from a 3V supply, the LT1611 replaces nonregulated “charge pump” solutions in many applications.
The LT1611 operates in a dual inductor inverting topology which filters the input side as well as the output side of the DC/DC converter. Fixed frequency switching ensures a clean output free from low frequency noise typically present with charge pump solutions. No load quiescent current of the LT1611 is 3mA, while in shutdown quiescent current drops to 0.5µA. The 36V switch allows VIN to VOUT differential of up to 33V.
The LT1611 is available in the 5-lead SOT-23 package.
- MR Head Bias
- Digital Camera CCD Bias
- LCD Bias
- GaAs FET Bias
- Positive-to-Negative Conversion
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
Technical Articles (3)
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Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.