Features and Benefits
- 4-Switch Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT
- Up to 98% Efficiency
- Proprietary Peak-Buck Peak-Boost Current Mode
- Wide VIN Range: 3V (Need EXTVCC ≥ 4.5V) to 60V
- ±1.5% Output Voltage Accuracy: 1V ≤ VOUT ≤ 60V
- ±4% Input or Output Current Accuracy with Monitor
- Spread Spectrum Frequency Modulation for Low EMI
- Integrated Bootstrap Diodes
- Adjustable and Synchronizable: 150kHz to 650kHz
- VOUT Disconnected from VIN During Shutdown
- Available in 28-Lead TSSOP with Exposed Pad and 28-Lead QFN (4mm × 5mm)
The LT8392 is a synchronous 4-switch buck-boost DC/ DC controller that regulates output voltage, input or output current from input voltage above, below, or equal to the output voltage. The proprietary peak-buck peak-boost current mode control scheme allows adjustable and synchronizable 150kHz to 650kHz fixed frequency operation, or internal ±15% triangle spread spectrum operation for low EMI. With 3V to 60V input voltage range, 1V to 60V output voltage capability, and seamless low noise transitions between operation regions, the LT8392 is ideal for voltage regulator, battery and super-capacitor charger applications in automotive, industrial, telecom, and even battery-powered systems.
The LT8392 provides input or output current monitor and power good flag. Fault protection function detects output short-circuit condition, during which the LT8392 retries, latches off, or keeps running.
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 DC2626A is a 4-switch synchronous buck-boost regulator that demonstrates the high power capability of the LT8392. The output is 12V and the maximum output current is 12A for up to 144W power delivery. The switching frequency is 200kHz and efficiency can exceed 97%.
The steady-state operating input voltage range of DC2626A in which the temperature of the components is less than 90°C is from 9V to 18V. The transient operating input voltage range of DC2626A is from 3V to 36V. The output voltage and EN/UVLO are all programmed by resistor dividers. EN/UVLO is set so the circuit will turn off when the input voltage falls below 3V and will turn on when the input voltage rises above 4V. The PCB has large copper planes and extensive vias for excellent high power thermal performance.
DC2626A features MOSFETs that complement the 5V gate drive of the LT8392 to achieve high efficiency. 40V AEC-Q101 MOSFETs are used on the input and output side of the four-switch topology. Ceramic capacitors are used at both the circuit input and output because of their small size and high ripple current capability. In addition to ceramic capacitors, there are bulk aluminum polymer capacitors on the input and output to make input and output stable during transient period.
The CTRL input is pulled up to the VREF pin through a 0Ω resistor to set the output current limit to its maximum, and an external voltage on CTRL can be used to lower the current limit if the resistor is removed. A capacitor at the SS pin programs soft-start.
To improve the EMI performance, the LT8392 has spread spectrum frequency modulation. With the SYNC/SPRD pin tied to INTVCC, LT8392 spreads its switching frequency ±15% around the programmed oscillator frequency.
The PGOOD status flag indicates when output voltage is within ±10% of the final regulation voltage.
The LT8392’s proprietary peak current mode buck-boost architecture ensures DC2626A runs either in discontinuous conduction mode (DCM) or pulse-skipping mode (PSM) without reverse inductor current. Both modes enhance the light load efficiency.
The demo circuit is designed to be easily reconfigured to suit other applications, including the example schematics in the data sheet. Consult the factory for assistance
High power operation, 3V input voltage operation, 4-switch buck-boost topology, proprietary peak current mode architecture, fault protection and output current monitoring make the LT8392 attractive for high power voltage regulator circuits and also circuits whose input voltage drops to 3V such as cold crank of car battery. It is also suitable for output current regulation such as battery chargers. The LT8392JFE is available in a thermally enhanced 28 lead TSSOP package. The LT8392 data sheet must be read in conjunction with the demo manual to properly use or modify demo circuit DC2626A.
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.
LTpowerCAD Project Files
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
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.