LT1931 - 1.2MHz/2.2MHz Inverting DC/DC Converters in ThinSOT
Features
- Fixed Frequency 1.2MHz/2.2MHz Operation
- Very Low Noise: 1mVP-P Output Ripple
- –5V at 350mA from 5V Input
- –12V at 150mA from 5V Input
- Uses Small Surface Mount Components
- Wide Input Range: 2.6V to 16V
- Low Shutdown Current: <1µA
- Low VCESAT Switch: 400mV at 1A
- Pin-for-Pin Compatible with the LT1611
- Low Profile (1mm) ThinSOT™ Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LT1931/LT1931A are the industry’s highest power inverting SOT-23 current mode DC/DC converters. Both parts include a 1A integrated switch allowing high current outputs to be generated in a small footprint. The LT1931 switches at 1.2MHz while the LT1931A switches at 2.2MHz. These high speeds enable the use of tiny, low cost capacitors and inductors 2mm or less in height. The LT1931 is capable of generating –5V at 350mA or –12V at 150mA from a 5V supply, while the LT1931A can generate –5V at 300mA using significantly smaller inductors. Both parts are easy pin-for-pin upgrades for higher power LT1611 applications.The LT1931/LT1931A operate in a dual inductor inverting topology that filters both the input side and output side current. Very low output voltage ripple approaching 1mVP-P can be achieved when ceramic output capacitors are used. Fixed frequency switching ensures a clean output free from low frequency noise typically present with charge pump solutions. The low impedance output remains within 1% of nominal during large load steps. The 36V switch allows VIN to VOUT differential of up to 34V.
The LT1931/LT1931A are available in the 5-lead ThinSOT package.
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 |
|---|---|---|---|---|---|
| LT1931AES5#PBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LT1931AES5#TRMPBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LT1931AES5#TRPBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LT1931AIS5#PBF | SOT-23 | S5 | I | 05-08-1635 | Yes |
| LT1931AIS5#TRMPBF | SOT-23 | S5 | I | 05-08-1635 | Yes |
| LT1931AIS5#TRPBF | SOT-23 | S5 | I | 05-08-1635 | Yes |
| LT1931ES5#PBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LT1931ES5#TRMPBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LT1931ES5#TRPBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LT1931IS5#PBF | SOT-23 | S5 | I | 05-08-1635 | Yes |
| LT1931IS5#TRMPBF | SOT-23 | S5 | I | 05-08-1635 | Yes |
| LT1931IS5#TRPBF | SOT-23 | S5 | I | 05-08-1635 | 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 | |
|---|---|---|---|---|---|---|
| LT1931AES5#PBF | SOT-23 | E | $2.46 | Yes | ||
| LT1931AES5#TRMPBF | SOT-23 | E | $2.46 | $2.08 | Yes | |
| LT1931AES5#TRPBF | SOT-23 | E | $2.46 | $2.06 | Yes | |
| LT1931AIS5#PBF | SOT-23 | I | $3.07 | Yes | ||
| LT1931AIS5#TRMPBF | SOT-23 | I | $3.07 | $2.18 | Yes | |
| LT1931AIS5#TRPBF | SOT-23 | I | $3.07 | $2.16 | Yes | |
| LT1931ES5#PBF | SOT-23 | E | $2.46 | Yes | ||
| LT1931ES5#TRMPBF | SOT-23 | E | $2.46 | $2.08 | Yes | |
| LT1931ES5#TRPBF | SOT-23 | E | $2.46 | $2.06 | Yes | |
| LT1931IS5#PBF | SOT-23 | I | $3.07 | Yes | ||
| LT1931IS5#TRMPBF | SOT-23 | I | $3.07 | $2.18 | Yes | |
| LT1931IS5#TRPBF | SOT-23 | I | $3.07 | $2.16 | 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.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC383B | LTC1930ES5/LTC1931ES5 Demo Board | 3 Circuits: Boost/SEPIC/Inverter, 5Vin to 12Vout1@300mA, 10V-16Vin to 12Vout2@300mA, 12Vin to -12Vout3@350mA | $75.00 | |
| DC397A | LT1930AES5/LT1931AES5 Demo Board | 3 Circuits: Boost/SEPIC/Inverter: 5Vin to 12Vout1@250mA, 10V-16Vin to 12Vout2@250mA, 12Vin to -12Vout3@250mA | $75.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LT1931AIS5#PBF | SOT-23 | I | $3.07 | Yes | ||
| LT1931AIS5#TRMPBF | SOT-23 | I | $3.07 | $2.18 | Yes | |
| LT1931AIS5#TRPBF | SOT-23 | I | $3.07 | $2.16 | Yes | |
| LT1931IS5#PBF | SOT-23 | I | $3.07 | Yes | ||
| LT1931IS5#TRMPBF | SOT-23 | I | $3.07 | $2.18 | Yes | |
| LT1931IS5#TRPBF | SOT-23 | I | $3.07 | $2.16 | Yes | |
| Buy Now • Request Samples | ||||||
Applications
- Disk Drive MR Head Bias
- Digital Camera CCD Bias
- LCD Bias
- GaAs FET Bias
- Local Low Noise/Low Impedance Negative Supply
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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
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To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LT1931
LT1931A
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.
