LT3091 - –36V, 1.5A Negative Linear Regulator with Programmable Current Limit


  • 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

Typical Application

LT3091 Typical Application
LT3091 Typical Application


The LT®3091 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.


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
LT3091EDE#PBF 4x3 DFN-14 DE E 05-08-1708 Yes
LT3091EDE#TRPBF 4x3 DFN-14 DE E 05-08-1708 Yes
LT3091EFE#PBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT3091EFE#TRPBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT3091ER#PBF DDPAK-7 R E 05-08-1462 Yes
LT3091ER#TRPBF DDPAK-7 R E 05-08-1462 Yes
LT3091ET7#PBF TO-220 T7 E 05-08-1422 (Std) Yes
LT3091HDE#PBF 4x3 DFN-14 DE H 05-08-1708 Yes
LT3091HDE#TRPBF 4x3 DFN-14 DE H 05-08-1708 Yes
LT3091HFE#PBF TSSOP-16 FE H 05-08-1663 (BC) Yes
LT3091HFE#TRPBF TSSOP-16 FE H 05-08-1663 (BC) Yes
LT3091HR#PBF DDPAK-7 R H 05-08-1462 Yes
LT3091HR#TRPBF DDPAK-7 R H 05-08-1462 Yes
LT3091HT7#PBF TO-220 T7 H 05-08-1422 (Std) Yes
LT3091IDE#PBF 4x3 DFN-14 DE I 05-08-1708 Yes
LT3091IDE#TRPBF 4x3 DFN-14 DE I 05-08-1708 Yes
LT3091IFE#PBF TSSOP-16 FE I 05-08-1663 (BC) Yes
LT3091IFE#TRPBF TSSOP-16 FE I 05-08-1663 (BC) Yes
LT3091IR#PBF DDPAK-7 R I 05-08-1462 Yes
LT3091IR#TRPBF DDPAK-7 R I 05-08-1462 Yes
LT3091IT7#PBF TO-220 T7 I 05-08-1422 (Std) Yes
LT3091MPDE#PBF 4x3 DFN-14 DE MP 05-08-1708 Yes
LT3091MPDE#TR 4x3 DFN-14 DE MP 05-08-1708 No
LT3091MPDE#TRPBF 4x3 DFN-14 DE MP 05-08-1708 Yes
LT3091MPFE#PBF TSSOP-16 FE MP 05-08-1663 (BC) Yes
LT3091MPFE#TRPBF TSSOP-16 FE MP 05-08-1663 (BC) Yes
LT3091MPR#PBF DDPAK-7 R MP 05-08-1462 Yes
LT3091MPR#TRPBF DDPAK-7 R MP 05-08-1462 Yes
LT3091MPT7 TO-220 T7 MP 05-08-1422 (Std) No
LT3091MPT7#PBF TO-220 T7 MP 05-08-1422 (Std) Yes

LT3091 Package Drawing
LT3091 Package Drawing
LT3091 Package Drawing
LT3091 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
LT3091EDE#PBF 4x3 DFN-14 E $4.10 $2.87 Yes
LT3091EDE#TRPBF 4x3 DFN-14 E $2.93 Yes
LT3091EFE#PBF TSSOP-16 E $4.10 $2.87 Yes
LT3091EFE#TRPBF TSSOP-16 E $2.93 Yes
LT3091ER#PBF DDPAK-7 E $4.57 $3.20 Yes
LT3091ER#TRPBF DDPAK-7 E $3.26 Yes
LT3091ET7#PBF TO-220 E $4.57 $3.20 Yes
LT3091HDE#PBF 4x3 DFN-14 H $5.24 $3.67 Yes
LT3091HDE#TRPBF 4x3 DFN-14 H $3.73 Yes
LT3091HFE#PBF TSSOP-16 H $5.24 $3.67 Yes
LT3091HFE#TRPBF TSSOP-16 H $3.73 Yes
LT3091HR#PBF DDPAK-7 H $5.82 $4.07 Yes
LT3091HR#TRPBF DDPAK-7 H $4.13 Yes
LT3091HT7#PBF TO-220 H $5.82 $4.07 Yes
LT3091IDE#PBF 4x3 DFN-14 I $4.76 $3.33 Yes
LT3091IDE#TRPBF 4x3 DFN-14 I $3.39 Yes
LT3091IFE#PBF TSSOP-16 I $4.76 $3.33 Yes
LT3091IFE#TRPBF TSSOP-16 I $3.39 Yes
LT3091IR#PBF DDPAK-7 I $5.33 $3.73 Yes
LT3091IR#TRPBF DDPAK-7 I $3.79 Yes
LT3091IT7#PBF TO-220 I $5.33 $3.73 Yes
LT3091MPDE#PBF 4x3 DFN-14 MP $10.79 $7.55 Yes
LT3091MPDE#TR 4x3 DFN-14 MP $10.85 $7.61 No
LT3091MPDE#TRPBF 4x3 DFN-14 MP $10.85 $7.61 Yes
LT3091MPFE#PBF TSSOP-16 MP $10.79 $7.55 Yes
LT3091MPFE#TRPBF TSSOP-16 MP $7.61 Yes
LT3091MPR#PBF DDPAK-7 MP $12.07 $8.45 Yes
LT3091MPR#TRPBF DDPAK-7 MP $8.51 Yes
LT3091MPT7 TO-220 MP $12.07 $8.45 No
LT3091MPT7#PBF TO-220 MP $12.07 $8.45 Yes
Buy NowRequest Samples
* 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
DC2276A LT3091EDE Demo Board | Negative LDO with Prog Current Limit, -1.5V ≤ VIN ≤ -36V, Vout = -1.25V/-2.5V/-5V/-12V/-15V @ 1.5A $100.00
Buy Now
Click here to view our complete list of demo boards


  • Post Regulator for Switching Supplies
  • Low Noise Instrumentation and RF Supplies
  • Rugged Industrial Supplies
  • Precision Power Supplies

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email with questions and comments.

Design Tools


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

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, 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

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:

Technical Support