LT1185 - Low Dropout Regulator
Features
- Low Resistance Pass Transistor: 0.25Ω
- Dropout Voltage: 0.75V at 3A
- ±1% Reference Voltage
- Accurate Programmable Current Limit
- Shutdown Capability
- Internal Reference Available
- Full Remote Sense
- Low Quiescent Current: 2.5mA
- Good High Frequency Ripple Rejection
- Available in 5-Lead TO-220 and DD Packages
Typical Application
Description
The LT1185 is a 3A low dropout regulator with adjustable current limit and remote sense capability. It can be used as a positive output regulator with floating input or as a standard negative regulator with grounded input. The output voltage range is 2.5V to 25V, with ±1% accuracy on the internal reference voltage.
The LT1185 uses a saturation-limited NPN transistor as the pass element. This device gives the linear dropout characteristics of a FET pass element with significantly less die area. High efficiency is maintained by using special anti-saturation circuitry that adjusts base drive to track load current. The “on resistance” is typically 0.25Ω. Accurate current limit is programmed with a single 1/8W external resistor, with a range of zero to three amperes. A second, fixed internal limit circuit prevents destructive currents if the programming current is accidentally overranged. Shutdown of the regulator output is guaranteed when the program current is less than 1µA, allowing external logic control of output voltage.
The LT1185 has all the protection features of previous LTC regulators, including power limiting and thermal shutdown.
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 |
|---|---|---|---|---|---|
| LT1185CQ#PBF | DDPAK-5 | Q | C | 05-08-1461 | Yes |
| LT1185CQ#TRPBF | DDPAK-5 | Q | C | 05-08-1461 | Yes |
| LT1185CT#06PBF | TO-220 | T | C | 05-08-1421 (Flow 06) | Yes |
| LT1185CT#30PBF | TO-220 | T | C | 05-08-1421 (Standard) | Yes |
| LT1185CT#33PBF | TO-220 | T | C | 05-08-1421 (Standard) | Yes |
| LT1185CT#PBF | TO-220 | T | C | 05-08-1421 (Standard) | Yes |
| LT1185IQ#PBF | DDPAK-5 | Q | I | 05-08-1461 | Yes |
| LT1185IQ#TRPBF | DDPAK-5 | Q | I | 05-08-1461 | Yes |
| LT1185IT#06PBF | TO-220 | T | I | 05-08-1421 (Flow 06) | Yes |
| LT1185IT#30PBF | TO-220 | T | I | 05-08-1421 (Standard) | Yes |
| LT1185IT#31PBF | TO-220 | T | I | 05-08-1421 (Standard) | Yes |
| LT1185IT#PBF | TO-220 | T | I | 05-08-1421 (Standard) | Yes |
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 | |
|---|---|---|---|---|---|---|
| LT1185CQ#PBF | DDPAK-5 | C | $4.50 | $3.80 | Yes | |
| LT1185CQ#TRPBF | DDPAK-5 | C | $3.92 | Yes | ||
| LT1185CT#06PBF | TO-220 | C | $4.33 | $3.55 | Yes | |
| LT1185CT#30PBF | TO-220 | C | $4.78 | $4.00 | Yes | |
| LT1185CT#33PBF | TO-220 | C | $4.78 | $4.00 | Yes | |
| LT1185CT#PBF | TO-220 | C | $4.33 | $3.55 | Yes | |
| LT1185IQ#PBF | DDPAK-5 | I | $5.83 | $4.75 | Yes | |
| LT1185IQ#TRPBF | DDPAK-5 | I | $4.87 | Yes | ||
| LT1185IT#06PBF | TO-220 | I | $5.83 | $4.75 | Yes | |
| LT1185IT#30PBF | TO-220 | I | $6.28 | $5.20 | Yes | |
| LT1185IT#31PBF | TO-220 | I | $6.28 | $5.20 | Yes | |
| LT1185IT#PBF | TO-220 | I | $5.83 | $4.75 | Yes | |
| Buy Now • Request Samples | ||||||
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
People Who Viewed This Product Also Viewed
- LT3015 - 1.5A, Low Noise, Negative Linear Regulator with Precision Current Limit
- LT3080 - Adjustable 1.1A Single Resistor Low Dropout Regulator
- LT3083 - Adjustable 3A Single Resistor Low Dropout Regulator
- LT1085 - 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulators
- LT1084 - 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulators
- LT1175 - 500mA Negative Low Dropout Micropower Regulator
- LT3081 - 1.5A Single Resistor Rugged Linear Regulator with Monitors
- LT1028 - Ultra Low Noise Precision High Speed Op Amps
- LT1083 - 7.5A, 5A, 3A Low Dropout Positive Adjustable Regulators
- LT1964 - 200mA, Low Noise, Low Dropout Negative Micropower Regulator
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 mylinear@linear.com with questions and comments.
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
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:
LT1185
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.