Features and Benefits
- Constant 500kHz Switching Frequency
- Easily Synchronizable
- Uses All Surface Mount Components
- Inductor Size Reduced to 5µH
- Saturating Switch Design: 0.4Ω
- Effective Supply Current: 2.5mA
- Shutdown Current: 20µA
- Cycle-by-Cycle Current Limiting
The LT1375/LT1376 are 500kHz monolithic buck mode switching regulators. A 1.5A switch is included on the die along with all the necessary oscillator, control and logic circuitry. High switching frequency allows a considerable reduction in the size of external components. The topology is current mode for fast transient response and good loop stability. Both fixed output voltage and adjustable parts are available.
A special high speed bipolar process and new design techniques achieve high efficiency at high switching frequency. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch. A shutdown signal will reduce supply current to 20µA on both parts. The LT1375 can be externally synchronized from 580kHz to 900kHz with logic level inputs.
The LT1375/LT1376 fit into standard 8-pin PDIP and SO packages, as well as a fused lead 16-pin SO with much lower thermal resistance. Full cycle-by-cycle short-circuit protection and thermal shutdown are provided. Standard surface mount external parts are used, including the inductor and capacitors.
For low input voltage applications with 3.3V output, see LT1507. This is a functionally identical part that can operate with input voltages between 4.5V and 12V.
- Portable Computers
- Battery-Powered Systems
- Battery Charger
- Distributed Power
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.
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.