Features and Benefits
- Wide Input Voltage Range: 3V to 60V
- Low IQ Burst Mode® Operation: 8μA
- Up to 95% Efficiency at 2MHz
- ±1.5% Internal 1V Voltage Reference
- 5V Split Gate Drive for Efficiency and EMI Optimization
- 100kHz to 2MHz Fixed Switching Frequency with External Clock Synchronization
- Spread Spectrum Frequency Modulation for Low EMI
- Accurate Enable Threshold with Hysteresis
- Programmable Output Soft-Start and Tracking
- Thermally-Enhanced 12-Lead MSOP Package
The LT8357 is a wide input range, current mode, DC/DC controller which can be configured as a boost, SEPIC or flyback converter. The LT8357 drives a low side N-channel power MOSFET with 5V split gate drive. The current mode architecture allows adjustable and synchronizable 100kHz to 2MHz fixed frequency operation, or internal 19% triangle spread spectrum operation for low EMI. At light load, either pulse-skipping mode or low-ripple Burst Mode operation can be selected. Additional features include output power good and output short circuit protection in SEPIC and flyback configurations.
With a wide 3V to 60V input voltage range and 8μA low quiescent current, the LT8357 provides a simple, compact and efficient solution for automotive, industrial, and battery-powered systems.
- Automotive and Industrial Systems
- Battery-Powered Systems
- Portable Electronic Equipment
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 (2)
Evaluation circuit EVAL-LT8357-AZ features the LT8357 as a 200kHz low EMI and low IQ, boost controller with a 24V output from 4.5V to 20V input. This evaluation circuit features Spread Spectrum Frequency Modulation (SSFM) and EMI filters to provide optimum EMI performance. The board also contains placeholders and an outline to attach clips for an optional EMI Shield attachment. This application circuit can output 2A (see Figure 4 Maximum Output Current vs VIN curve in the user guide). When placed in shutdown, the converter has very low quiescent current, ideal in automotive and other battery-powered applications. PULSE SKIP and BURST modes are selectable with jumper JP1. Each user-selectable option enables low quiescent current at light load and can also be combined with SSFM operation using JP1.
The LT8357 boost controller IC operates over an input range of 3V to 60V, suitable for automotive, telecom and industrial applications. It exhibits a low quiescent current of 8μA, making it ideal for battery-operated systems. It drives a low side N-channel power MOSFET with a 5V split gate drive. The converter provides adjustable and synchronizable operation from 100kHz to 2MHz with SSFM option. At light load, either PULSE SKIP or low-ripple BURST mode can be selected to improve the efficiency. The LT8357 packs popular features such as soft-start, input undervoltage lockout, adjustable switching frequency and clock synchronization. The Power Good (PGOOD) flag indicates when the output voltage is in regulation.
The LT8357 comes in a thermally enhanced 12-lead plastic MSE package. The LT8357 data sheet gives a complete description of the part, pins, features, operation, and application information. The data sheet must be read in conjunction with the user guide for EVAL-LT8357-AZ.
Demonstration circuit 2937A features the LT8357 as a 360kHz low IQ, high power boost converter with a 48V output from 10V to 40V input. This demonstration circuit features spread spectrum frequency modulation (SSFM) and split gate driver pins for the high power, high voltage switch. The converter can output 2A and higher (see Figure 3 in the demo manual). When placed in shutdown, the converter has very low quiescent current, ideal in automotive and other battery-powered applications. Low quiescent current can be achieved with both pulse-skipping and Burst Mode® operation as jumper selections on this demonstration circuit.
The LT8357 boost controller IC operates over an input range of 3V to 60V, suitable for automotive, telecom and industrial applications. It also exhibits a low quiescent current of 8μA, making it ideal for battery-operated systems. It drives a low side N-channel power MOSFET with a 5V split gate drive. The controller provides adjustable and synchronizable operation from 100kHz to 2MHz. At light load, either pulse-skipping or low-ripple Burst Mode operation can be selected to improve the efficiency. It also packs many popular features such as soft-start, input undervoltage lockout, adjustable frequency and clock synchronization. PGOOD indicates when the output voltage is in regulation.
The LT8357 comes in a thermally enhanced 12-lead plastic MSE package. The LT8357 data sheet gives a complete description of the part, pins, features, operation and application information. The data sheet must be read in conjunction with the demo manual for DC2937A.
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:
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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.