Features and Benefits
- 3A Output Current
- 2.25V to 5.5V Input Voltage Range
- Low Output Ripple Burst Mode® Operation: IQ = 70μA
- ±1% Output Voltage Accuracy
- Output Voltage Down to 0.6V
- High Efficiency: Up to 95%
- Low Dropout Operation: 100% Duty Cycle
- Shutdown Current: ≤1μA
- Adjustable Switching Frequency: Up to 4MHz
- Optional Active Voltage Positioning (AVP) with Internal Compensation
- Selectable Pulse-Skipping/Forced Continuous/Burst Mode Operation with Adjustable Burst Clamp
- Programmable Soft-Start
- Inputs for Start-Up Tracking or External Reference
- DDR Memory Mode, IOUT = ±1.5A
- Available in Thermally Enhanced 20-Pin (3mm × 4mm) QFN and TSSOP Packages
The LTC3612 is a low quiescent current monolithic synchronous buck regulator using a current mode, constant frequency architecture. The no-load DC supply current in sleep mode is only 70μA while maintaining the output voltage (Burst Mode operation) at no load, dropping to zero current in shutdown. The 2.25V to 5.5V input supply voltage range makes the LTC3612 ideally suited for single Li-Ion as well as fixed low voltage input applications. 100% duty cycle capability provides low dropout operation, extending the operating time in battery-powered systems.
The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. For switching noise-sensitive applications, the LTC3612 can be synchronized to an external clock at up to 4MHz.
Forced continuous mode operation in the LTC3612 reduces noise and RF interference. Adjustable compensation allows the transient response to be optimized over a wide range of loads and output capacitors.
The internal synchronous switch increases efficiency and eliminates the need for an external catch diode, saving external components and board space. The LTC3612 is offered in a leadless 20-pin 3mm × 4mm QFN or a thermally enhanced 20-pin TSSOP package.
- Point-of-Load Supplies
- Distributed Power Supplies
- Portable Computer Systems
- DDR Memory Termination
- Handheld Devices
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)
Demo Circuit 1574 is a high efficiency, high frequency step-down converter, incorporating the LTC3612 monolithic synchronous regulator. The DC1574A has an input voltage range of 2.25V to 5.5V, and is capable of delivering up to 3A of output current. The output voltage of the DC1574A can be set as low as 0.6V, the reference voltage of the LTC3612. The operating frequency range of the DC1574A is either set to a fixed 2.25 MHz by connecting the frequency pin to SVIN, set by an external resistor, or synchronized to an external clock, with a range up to 4 MHz. At low load currents, the DC1574A can operate in either noise sensitive applications, due to the capability of the LTC3612 to operate in pulse-skipping mode, or in high efficiency applications, because the LTC3612 also has Burst-Mode capability. The Burst Mode clamp can be set externally.
Demo Circuit 1310 is a high efficiency, high frequency step-down converter, incorporating the LTC3612 monolithic synchronous regulator. The DC1310A has an input voltage range of 2.25V to 5.5V, and is capable of delivering up to 3A of output current. The output voltage of the DC1310A can be set as low as 0.6V, the reference voltage of the LTC3612. The operating frequency range of the DC1310A is either set to a fixed 2.25 MHz by connecting the frequency pin to SVin, set by an external resistor, or synchronized to an external clock, with a range up to 4 MHz. At low load currents, the DC1310A can operate in either noise sensitive applications, due to the capability of the LTC3612 to operate in pulse-skipping mode, or in high efficiency applications, because the LTC3612 also has Burst-Mode capability.
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.