New Content (1)
Features and Benefits
- Wide Input Voltage Range: 3.0V to 40V
- Low Quiescent Current in Burst Mode® Operation
- <6μA IQ
- <20mVP-P Output Ripple
- Synchronous Operation for High Efficiency
- Monolithic 40V, 240mΩ Power Switches
- 100% Duty Cycle PassThru™ Mode for Boost Preregulation Applications
- Adjustable and Synchronizable: 300kHz to 3MHz
- Spread Spectrum for Reduced EMI/EMC Emissions
- Accurate EN/UVLO
- Internal Compensation
- 20MΩ Internal Feedback Divider
- Output Voltage Up to 40V
- Available in 10-Lead MSOP Package
- AEC-Q100 Automotive Qualification in Progress
The LT8338 is a synchronous monolithic step-up regulator that provides high efficiency for input and output up to 40V. It consumes only 6μA quiescent current at Burst Mode operation to maintain high efficiency at very low output current, while keeping the output ripple below 20mVP-P. The LT8338 switching frequency can be set with an external resistor over the range of 300kHz to 3MHz. A SYNC/MODE pin allows synchronization to an external clock. It can also be used to select between Burst Mode operation and pulse-skipping mode, or to enable spread spectrum modulation to reduce EMI. The EN/UVLO pin has an accurate 1V threshold and can be used to program VIN UVLO or to shut down the part. The LT8338 enters 100% duty cycle PassThru mode when VIN is higher than the regulated VOUT. The LT8338 also features frequency foldback and internal soft-start for inductor current control during start-up.
- Industrial and Automotive Power Supplies
- Battery-Powered Systems
- General Purpose Step-Up
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit DC2907A features the LT8338, a low IQ, Synchronous Boost Converter in a thermally enhanced 10-lead plastic MSOP package. DC2907A is designed to convert a 4V to 16V source to 24V output, with up to 460mA of load current, depending on the input voltage. It was designed with a switching frequency of 2.2MHz.
DC2907A contains a selectable jumper, JP1, to aid in the selection of any of the five modes of operation. The default setting is Burst mode.
This converter features Spread Spectrum Frequency Modulation, SSFM. The input and output filters installed on the PCB help suppress EMI noise, but the use of SSFM makes it easier to pass CISPR25 class 5 conducted and radiated emissions testing for automotive vehicles. To perform an EMI evaluation for this converter include the input filter by connecting the input source to the VEMI terminal and select the Burst+SSFM JP1 setting.
EMI filters may not be necessary for all applications. For a lower parts count and BOM cost EMI filters can be removed. To do so, replace FB1 and FB2 with a zero ohm jumpers and remove all input and output filter components located inside the dashed-line rectangles on the schematic, plus C1 and C13.
Proper board layout is essential for maximum thermal performance. See the datasheet section “Thermal Considerations”.
The Performance Summary section details the ratings of the DC2907A at room temperature. The LT8338 datasheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this quick start guide for DC2907A.
The LT8338 is available in a thermally-enhanced 10 lead plastic MSOP package.
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.
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.
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.