Features and Benefits
- No Current Sense Resistor Required
- High Output Currents Easily Achieved
- Internal Soft-Start Ramps VOUT
- Wide VIN Range: 2.75V to 9.8V
- Low Dropout: 100% Duty Cycle
- Constant Frequency 550kHz Operation
- Low Ripple Pulse Skipping Operation at Light Load
- Output Voltage as Low as 0.8V
- ±1.5% Voltage Reference Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- Only 8μA Supply Current in Shutdown
- Low Profile 8-Lead SOT-23 (1mm) and (3mm × 2mm) DFN (0.75mm) Packages
The LTC3772B is a constant frequency current mode step-down DC/DC controller in a low profile 8-lead SOT-23 (ThinSOT™) and a 3mm × 2mm DFN package. The No RSENSE™ architecture eliminates the need for a current sense resistor, improving efficiency and saving board space.
The LTC3772B automatically switches into pulse skipping operation at light loads. It consumes only 200μA of quiescent current under a no-load condition.
The LTC3772B incorporates an undervoltage lockout feature that shuts down the device when the input voltage falls below 2V. To maximize the runtime from a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High switching frequency of 550kHz allows the use of a small inductor and capacitors. An internal soft-start smoothly ramps the output voltage from zero to its regulation point.
- 1- or 2-Cell Li-Ion Battery-Powered Applications
- Wireless Devices
- Portable Computers
- Distributed Power Systems
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 924 is a No RSENSE™ constant frequency step-down DC/DC converter featuring the LTC3772B (Burst Mode disabled), nonsynchronous controller in a 3mm x 2mm DFN package. The demo board has an input voltage range of 2.75V to 8V and provides 2A at one of the three jumper-selectable output voltages: 1.8V, 2.5V or 3.3V.
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:
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.