Features and Benefits
- Wide Input Voltage Range: 5V to 80V
- Single Feedback Pin for Positive or Negative Output Voltage
- Internal 3.3A/84V Power Switch
- Current Mode Control Provides Excellent Transient Response
- Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor
- Synchronizeable to an External Clock
- Low Shutdown Current < 1μA
- Internal 7.2V Low Dropout Voltage Regulator
- Programmable Input Undervoltage Lockout with Hysteresis
- Programmable Soft-Start
- Thermally Enhanced QFN (5mm × 6mm) Package
The LT3958 is a wide input range, current mode, DC/DC converter which is capable of generating either positive or negative output voltages. It can be configured as either a boost, flyback, SEPIC or inverting converter. It features an internal low side N-channel power MOSFET rated for 84V at 3.3A and driven from an internal regulated 7.2V supply. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages.
The operating frequency of LT3958 can be set with an external resistor over a 100kHz to 1MHz range, and can be synchronized to an external clock using the SYNC pin. A minimum operating supply voltage of 5V, and a low shutdown quiescent current of less than 1μA, make the LT3958 ideally suited for battery-powered systems.
The LT3958 features soft-start and frequency foldback functions to limit inductor current during start-up.
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 1569A is a High Voltage Monolithic Boost Converter featuring the LT3958. The LT3958 can be configured as a boost, flyback, SEPIC, and inverting converter, but the demonstration circuit is assembled as a boost. The input voltage range is 11V to 40V and the output voltage is 48V with 500mA over the entire input voltage range. The LT3958 has an internal n-channel 3.3A, 84V power switch for high voltage, power, and efficiency. The dual paddle package provides excellent heat dissipation for the internal power switch. The LT3958 current-mode dc/dc converter features adjustable switching frequency, soft-start, compensation, shutdown and undervoltage lockout with hysteresis, and a feedback pin (FBX) that can be used in both positive and negative applications. A SYNC input can be used to synchronize the switching at a frequency higher than the IC is programmed.
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.
Design tools for the following parts are available in LTpowerCAD:
LT3958 Companion Parts
Recommended Related Parts
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.