Features and Benefits
- Wide VIN Range: 2.7V to 17V
- Wide VOUT Range: 0.6V to VIN
- 95% Max Efficiency
- Low IQ < 3.5μA, Zero-Current Shutdown
- Constant Frequency (1MHz/2.25MHz)
- Full Dropout Operation with Low IQ
- 1A Rated Output Current
- ±1% Output Voltage Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- Synchronizable to External Clock
- Pulse-Skipping, Forced Continuous, Burst Mode® Operation
- Internal Compensation and Soft-Start
- Overtemperature Protection
- Compact 6-Lead DFN (2mm × 3mm) Package or Thermally-Enhanced MS8E Package with Power Good Output and Independent SGND Pin
The LTC3621/LTC3621-2 is a high efficiency 17V, 1A synchronous monolithic step-down regulator. The switching frequency is fixed to 1MHz or 2.25MHz with a ±40% synchronizing range. The regulator features ultralow quiescent current and high efficiencies over a wide VOUT range.
The step-down regulator operates from an input voltage range of 2.7V to 17V and provides an adjustable output range from 0.6V to VIN while delivering up to 1A of output current. A user-selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency; Burst Mode operation provides the highest efficiency at light loads, while pulse-skipping mode provides the lowest voltage ripple. The MODE pin can also be used to allow the user to sync the switching frequency to an external clock.
- Portable-Handheld Scanners
- Industrial and Embedded Computing
- Automotive Applications
- Emergency Radio
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 (2)
Demonstration circuit 1864A is a step-down converter, capable of delivering up to 1A of output current from a minimum input voltage of 2.7V. The DC1864A uses the power-saving LTC3621-2 2.25MHz monolithic synchronous buck regulator that comes in a tiny 2mm × 3mm 6-lead DFN package. The LTC3621-2 IC quiescent currents can be as low as 3.5μA in normal operation, and less than 0.1μA in shutdown. The output voltage range of the DC1864A is from as low as 0.6V, the reference voltage of the LTC3621‑2, to as high as the maximum input voltage, 17V.
Demonstration circuit 1863 is a step-down converter, capable of delivering up to 1A of output current from a minimum input voltage of 2.7V. The DC1863A uses the power-saving LTC3621 1MHz monolithic synchronous buck regulator in a small 8-lead MS8 package. The LTC3621 IC quiescent currents can be as low as 3.5μA in normal operation, and less than 0.1μA in shut down. The output voltage range of the DC1863A is from as low as 0.6V, the reference voltage of the LTC3621, to as high as the maximum input voltage, 17V.
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.
To open the project file for this circuit:
Step 1: Download and install LTpowerCAD on your computer.
Step 2: Click on the link(s) in the section below to download part-specific project files.
Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.
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.