LT3751 - High Voltage Capacitor Charger Controller with Regulation
Features
- Charges Any Size Capacitor
- Low Noise Output in Voltage Regulation Mode
- Stable Operation Under a No-Load Condition
- Integrated 2A MOSFET Gate Driver with Rail-to-Rail Operation for VCC ≤ 8V
- Selectable 5.6V or 10.5V Internal Gate Drive Voltage Clamp
- User-Selectable Over/Undervoltage Detect
- Easily Adjustable Output Voltage
- Primary or Secondary Side Output Voltage Sense
- Wide Input VCC Voltage Range (5V to 24V)
- Available in 20-Pin QFN 4mm × 5mm and 20-Lead TSSOP Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LT3751 is a high input voltage capable flyback controller designed to rapidly charge a large capacitor to a user-adjustable high target voltage set by the transformer turns ratio and three external resistors. Optionally, a feedback pin can be used to provide a low noise high voltage regulated output.
The LT3751 has an integrated rail-to-rail MOSFET gate driver that allows for efficient operation down to 4.75V. A low 106mV differential current sense threshold voltage accurately limits the peak switch current. Added protection is provided via user-selectable overvoltage and undervoltage lockouts for both VCC and VTRANS. A typical application can charge a 1000μF capacitor to 500V in less than one second.
The CHARGE pin is used to initiate a new charge cycle and provides ON/OFF control. The DONE pin indicates when the capacitor has reached its programmed value and the part has stopped charging. The FAULT pin indicates when the LT3751 has shut down due to either VCC or VTRANS voltage exceeding the user-programmed supply tolerances.
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 |
|---|---|---|---|---|---|
| LT3751EFE#PBF | TSSOP-20 | FE | E | 05-08-1663 (CB) | Yes |
| LT3751EFE#TRPBF | TSSOP-20 | FE | E | 05-08-1663 (CB) | Yes |
| LT3751EUFD#PBF | 4x5 QFN-20 | UFD | E | 05-08-1711 | Yes |
| LT3751EUFD#TRPBF | 4x5 QFN-20 | UFD | E | 05-08-1711 | Yes |
| LT3751IFE#PBF | TSSOP-20 | FE | I | 05-08-1663 (CB) | Yes |
| LT3751IFE#TRPBF | TSSOP-20 | FE | I | 05-08-1663 (CB) | Yes |
| LT3751IUFD#PBF | 4x5 QFN-20 | UFD | I | 05-08-1711 | Yes |
| LT3751IUFD#TRPBF | 4x5 QFN-20 | UFD | I | 05-08-1711 | 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 | |
|---|---|---|---|---|---|---|
| LT3751EFE#PBF | TSSOP-20 | E | $5.46 | $3.82 | Yes | |
| LT3751EFE#TRPBF | TSSOP-20 | E | $3.88 | Yes | ||
| LT3751EUFD#PBF | 4x5 QFN-20 | E | $5.54 | $3.65 | Yes | |
| LT3751EUFD#TRPBF | 4x5 QFN-20 | E | $3.71 | Yes | ||
| LT3751IFE#PBF | TSSOP-20 | I | $6.06 | $4.24 | Yes | |
| LT3751IFE#TRPBF | TSSOP-20 | I | $4.30 | Yes | ||
| LT3751IUFD#PBF | 4x5 QFN-20 | I | $6.16 | $4.06 | Yes | |
| LT3751IUFD#TRPBF | 4x5 QFN-20 | I | $4.12 | 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 |
|---|---|---|---|
| DC1322A | LT3751EUFD Demo Board | 8V VIN 40V; VOUT = 300V as a 400uF Capacitor Charger | $125.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LT3751IFE#PBF | TSSOP-20 | I | $6.06 | $4.24 | Yes | |
| LT3751IFE#TRPBF | TSSOP-20 | I | $4.30 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- High Voltage Regulated Supply
- High Voltage Capacitor Charger
- Professional Photoflash Systems
- Emergency Strobe
- Security/Inventory Control Systems
- Detonators
People Who Viewed This Product Also Viewed
- LT3750 - Capacitor Charger Controller
- LT3748 - 100V Isolated Flyback Controller
- LT3757 - Boost, Flyback, SEPIC and Inverting Controller
- LT3758 - High Input Voltage, Boost, Flyback, SEPIC and Inverting Controller
- LT3796/LT3796-1 - 100V Constant-Current and Constant-Voltage Controller with Dual Current Sense
- LT3080 - Adjustable 1.1A Single Resistor Low Dropout Regulator
- LT8300 - 100VIN Micropower Isolated Flyback Converter with 150V/260mA Switch
- LT8705 - 80V VIN and VOUT Synchronous 4-Switch Buck- Boost DC/DC Controller
- LT4320/LT4320-1 - Ideal Diode Bridge Controller
- LT3573 - Isolated Flyback Converter without an Opto-Coupler
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:
LT3751
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.
