Features and Benefits
- Low Operating IQ: 12µA (14V VIN to 3.3V VOUT)
- Wide Input Voltage Range: 4.5V to 40V
- Output Voltage Up to 40V
- Spread Spectrum Operation
- RSENSE or DCR Current Sensing
- PassThru™/100% Duty Cycle Capable
- Programmable Fixed Frequency (100kHz to 3MHz)
- Phase-Lockable Frequency (100kHz to 3MHz)
- Selectable Continuous, Pulse-Skipping, or Low Ripple Burst Mode® Operation at Light Loads
- Low Shutdown IQ: 1.2μA
- Thermally Enhanced 16-Pin 3mm × 3mm QFN and MSOP Packages
- AEC-Q100 Qualified for Automotive Applications
The LTC7803 is a high performance, 100% Duty Cycle Capable, synchronous step-down DC/DC switching regulator controller that drives an all N-channel power MOSFET stage. Synchronous rectification increases efficiency, reduces power losses and eases thermal requirements. A constant frequency current mode architecture allows a phase-lockable switching frequency of up to 3MHz. The LTC7803 operates from a wide 4.5V to 40V input supply range.
The very low no-load quiescent current extends operating runtime in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.
The LTC7803 additionally features spread spectrum operation which significantly reduces the peak radiated and conducted noise on both the input and output supplies, making it easier to comply with electromagnetic interference (EMI) standards.
- Automotive and Transportation
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 DC2834A is a DC/DC synchronous step-down converter featuring the LTC7803 (MSE package), a spread spectrum or constant frequency current mode synchronous step-down controller. The DC2834A generates a 3.3V of output voltage.
The 500kHz constant switching frequency operation results in a small and efficient circuit.
The converter provides high output voltage accuracy (typically ±2%) over wide load range with no minimum load requirement.
The DC2834A supports two ways of biasing the controller: directly from the input voltage or output rail through EXTVCC. The third possibility is connecting an external voltage source to EXTVCC terminal.
The DC2834A supports extremely wide switching frequency range from 100kHz to 3MHz. The spread spectrum operation reduces the peak radiated and conducted noise to simplify compliance with electromagnetic interference (EMI) standards.
The DC2834A has a small circuit footprint, is a high performance and high density solution for telecom, automotive and Power over Ethernet applications.
Features & Benefits
- Wide input voltage range: from 5V to 38V
- High load current, up to 20A
- Extremely low quiescent current: 15μA in sleep mode and as low as 1μA at shutdown
- Ability to select spread spectrum or fixed frequency
- Selectable pulse-skipping, forced continuous operation or low ripple Burst Mode® operation at light loads
- Synchronization with external clock
- The DC2834A supports RSENSE or inductor DCR current sensing (optional).
Documentation & Resources
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.
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:
LTC7803 Companion Parts
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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.