Alternative Parts
Overview
Features and Benefits
- Output Current: 1.5A
- Single Resistor Sets Output Voltage
- 50μA SET Pin Current: ±1% Initial Accuracy
- Programmable Current Limit
- Positive or Negative Output Current Monitor
- Parallelable for Higher Current and Heat Spreading
- Low Dropout Voltage: 300mV
- Low Output Noise: 18μVRMS (10Hz to 100kHz)
- Configurable as a 3-Terminal Floating Regulator
- Wide Input Voltage Range: –1.5V to –36V
- Rail-to-Rail Output Voltage Range: 0V to –32V
- Positive/Negative Shutdown Logic or UVLO
- Programmable Cable Drop Compensation
- Load Regulation: 1.2mV (1mA to 1.5A)
- Stable with 10μF Minimum Output Capacitor
- Stable with Ceramic or Tantalum Capacitors
- Thermally Enhanced 14-Lead 4mm × 3mm DFN, 16-Lead TSSOP, 7-Lead TO-220 and DD Packages
Product Details
The LT3091 is a 1.5A, low dropout negative linear regulator that is easily paralleled to increase output current or spread heat on surface mounted boards. Designed with a precision current reference followed by a high performance rail-to-rail voltage buffer, this regulator finds use in applications requiring precision output, high current with no heat sink, output adjustability to zero and low dropout voltage. The device can also be configured as a 3-terminal floating regulator.
The LT3091 features fast transient response, high PSRR and output noise as low as 18μVRMS. The LT3091 generates a wide output voltage range (0V to –32V) while maintaining unity gain operation. This yields virtually constant bandwidth, load regulation, PSRR and noise, independent of the programmed output voltage.
The LT3091 supplies 1.5A at a typical dropout voltage of 300mV. Operating quiescent current is nominally 1.2mA and drops to << 1μA in shutdown. A single resistor adjusts the LT3091’s precision programmable current limit. The device’s positive or negative current monitor either sources a current (0.25mA/A) or sinks a current (0.5mA/A) proportional to output current. Built-in protection includes reverse output protection, internal current limit with foldback and thermal shutdown with hysteresis.
Applications
- Post Regulator for Switching Supplies
- Low Noise Instrumentation and RF Supplies
- Rugged Industrial Supplies
- Precision Power Supplies
Product Categories
Markets and Technologies
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Documentation & Resources
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R531 Reliability Data3/26/2018
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DC2276A - Demo Manual9/29/2015
Tools & Simulations
LTspice
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:
Product Recommendations
LT3091 Companion Parts
Recommended Related Parts
Design Resources
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PCN-PDN Information
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Support & Discussions
LT3091 Discussions
Sample & Buy
Ordering FAQs
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Buy Now Pricing
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List Pricing
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Lead Times
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Sampling
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Evaluation Boards
Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.