Features and Benefits
- Wide Input Voltage Range: 3.0V to 42V
- Ultralow Quiescent Current Burst Mode® Operation:
- <2.5µA IQ Regulating 12VIN to 3.3VOUT
- Output Ripple <10mVP-P
- High Efficiency 2MHz Synchronous Operation:
- >93% Efficiency at 1A, 5VOUT from 12VIN
- 3A Maximum Continuous Output
- Fast Minimum Switch-On Time: 45ns
- Adjustable and Synchronizable: 200kHz to 2.2MHz
- Spread Spectrum Frequency Modulation for Low EMI
- Allows Use of Small Inductors
- Low Dropout
- Peak Current Mode Operation
- Accurate 1V Enable Pin Threshold
- Internal Compensation
- Output Soft-Start and Tracking
- Small 10-Lead or 16-Lead MSOP Package
The LT8609/LT8609A/LT8609B is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7µA of nonswitching quiescent current. The LT8609/LT8609A/LT8609B can deliver 3A of continuous current. Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock, or spread spectrum modulation for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN UVLO or to shut down the part. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up while the PG flag signals when VOUT is within ±8.5% of the programmed output voltage as well as fault conditions. The LT8609A has slower switch edges for lower EMI emissions. The LT8609B APPLICATIONS operates in pulse-skipping mode only.
|Pulse-Skipping Mode, Burst Mode Operation||Switch Edge Speed|
- GSM Transceivers
- General Purpose Step Down
- Low EMI Step Down
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)
Demonstration circuit 2195B is a 42V, 2A micropower synchronous step-down regulator featuring the LT8609 or LT8609A. There are two assembly versions. DC2195B-A is for the LT8609A and DC2195B-B (and DC2195A) is for the LT8609. The difference is the LT8609A has slower edge speeds for improved EMI at the expense of a small efficiency loss.
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:
Press Releases (1)
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.