Features and Benefits
- Wide Input Range: 3V to 25V
- Short-Circuit Protected Over Full Input Range
- 2A Output Current Capability
- Adjustable/Synchronizable Fixed Frequency Operation from 250kHz to 2.2MHz
- Soft-Start/Tracking Capability
- Output Adjustable Down to 0.8V
- Adjustable Linear Regulator/Driver with 13mA Output Capability
- Power Good Comparator with Complementary Outputs
- Low Shutdown Current: 12μA
- Thermally Enhanced 3mm × 3mm DFN Package
The LT1939 is a current mode PWM step-down DC/DC converter with an internal 2.3A switch. The wide input range of 3V to 25V makes the LT1939 suitable for regulating power from a wide variety of sources, including automotive batteries, industrial supplies and unregulated wall adapters.
Resistor-programmable 250kHz to 2.2MHz frequency range and synchronization capability enable optimization between efficiency and external component size. Cycle-by-cycle current limit, frequency foldback and thermal shutdown provide protection against a shorted output. The soft-start feature controls the ramp rate of the output voltage, eliminating input current surge during start-up, and also provides output tracking.
The LT1939 contains an internal NPN transistor with feedback control which can be conﬁgured as a linear regulator or as a linear regulator controller.
The LT1939’s low current shutdown mode (<12μA) enables easy power management in battery-powered systems.
- Automotive Battery Regulation
- Industrial Control
- Wall Transformer Regulation
- Distributed Power Regulation
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)
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:
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Step 2: Click on the link in the section below to download a demonstration circuit.
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Models for the following parts are available in LTspice:
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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.