Features and Benefits
- Wide Input Range: 3.1V to 25V
- Two Switching Regulators with 3A Output Capability
- Independent Supply to Each Regulator
- Adjustable/Synchronizable Fixed Frequency Operation from 250kHz to 1.5MHz
- Antiphase Switching
- Outputs Can be Paralleled
- Independent, Sequential, Ratiometric or Absolute Tracking Between Outputs
- Independent Soft-Start and Power Good Pins
- Enhanced Short-Circuit Protection
- Low Dropout: 95% Maximum Duty Cycle
- Low Shutdown Current: <10µA
- 20-Lead TSSOP Package with Exposed Leadframe
The LT3501 is a dual current mode PWM step-down DC/DC converter with two internal 3.5A switches. Independent input voltage, feedback, soft-start and power good pins for each channel simplify complex power supply tracking/sequencing requirements.
Both converters are synchronized to either a common external clock input or a resistor programmable ﬁ xed 250kHz to 1.5MHz internal oscillator. At all frequencies, a 180° phase relationship between channels is maintained, reducing voltage ripple and component size. Programmable frequency allows for optimization between efﬁ ciency and external component size.
Minimum input-to-output voltage ratios are improved by allowing the switch to stay on through multiple clock cycles, only switching off when the boost capacitor needs recharging, resulting in ~95% maximum duty cycle.
Each output can be independently disabled using its own soft-start pin, or by using the SHDN pin the entire part can be placed in a low quiescent current shutdown mode.
The LT3501 is available in a 20-lead TSSOP package with exposed leadframe for low thermal resistance.
- DSP Power Supplies
- Disc Drives
- DSL/Cable Modems
- Wall Transformer Regulation
- Distributed Power Regulation
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demo circuit 964A is a dual monolithic step-down DC/DC converter featuring the LT3501. The demo circuit is designed for 3.3V/3A and 1.8V/3A outputs from a 4.5V to 24V input. Independent input voltage, feedback, soft-start and power good pins for each channel simplify complex power supply tracking/sequencing requirements.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, 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.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.