LT3504 - Quad 40V/1A Step-Down Switching Regulator with 100% Duty Cycle Operation
Features
- Wide Input Range: 3.2V to 40V
- Four 1A Outputs
- 100% Duty Cycle Operation
- Resistor-Programmed Constant Frequency
- Short-Circuit Robust
- Wide SYNC Range: 350kHz to 2.2MHz
- Anti-Phase Switching Reduces Ripple
- 800mV FB Voltage
- Independent Run/Soft-Start Pins
- Shutdown with UVLO
- Internal Compensation
- Thermal Shutdown
- Tiny 28-Lead (4mm × 5mm) Thermally Enhanced QFN Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LT®3504 consists of four 1A output current buck regulators. The LT3504 has a wide operating input range of 3.2V to 40V. An on-chip boost regulator allows each channel to operate up to 100% duty cycle and eliminates the need for four external charge pump circuits. The LT3504 is designed to minimize external component count and results in a simple and small application circuit.
The LT3504 operates robustly in fault conditions. Cycleby- cycle peak current limit and catch diode current limit sensing protect the part during overload conditions. Thermal shutdown protects the power switches at elevated temperatures. Soft-start helps keep the peak inductor current under control during startup.
The LT3504 also features output voltage tracking and sequencing, programmable frequency, programmable undervoltage lockout, and a power good pin to indicate when all outputs are in regulation.
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 |
|---|---|---|---|---|---|
| LT3504EUFD#PBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LT3504EUFD#TRPBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LT3504IUFD#PBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LT3504IUFD#TRPBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | 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 | |
|---|---|---|---|---|---|---|
| LT3504EUFD#PBF | 4x5 QFN-28 | E | $5.00 | $3.50 | Yes | |
| LT3504EUFD#TRPBF | 4x5 QFN-28 | E | $3.56 | Yes | ||
| LT3504IUFD#PBF | 4x5 QFN-28 | I | $5.50 | $3.85 | Yes | |
| LT3504IUFD#TRPBF | 4x5 QFN-28 | I | $3.91 | 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 |
|---|---|---|---|
| DC1207A | LT3504 Demo Board | Quad Buck, 5.4V ≤ VIN ≤ 40V, Vout1 - Vout4 = 5V/3.3V/2.5V/1.8V @ 1A Each | $175.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LT3504IUFD#PBF | 4x5 QFN-28 | I | $5.50 | $3.85 | Yes | |
| LT3504IUFD#TRPBF | 4x5 QFN-28 | I | $3.91 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Automotive Battery Regulation
- Industrial Control Supplies
- Wall Transformer Regulation
- Distributed Supply Regulation
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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
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:
LT3504
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.
