Features and Benefits
- Synchronous Operation for Highest Efficiency and Reduced Heat Dissipation
- Wide VIN Range: 4.5V to 40V and Operates Down to 1V After Start-Up
- Output Voltage Up to 40V
- Low Operating IQ: 14μA
- Spread Spectrum Operation
- PassThru™/100% Duty Cycle Capability for Synchronous MOSFET
- RSENSE or Inductor DCR Current Sensing
- 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 Qualification in Progress
The LTC7804 is a high performance synchronous boost 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 LTC7804 operates from a wide 4.5V to 40V input supply range. When biased from the boost converter output, the LTC7804 can operate from an input supply as low as 1V after startup.
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 LTC7804 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
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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 DC2846A is a DC/DC synchronous boost converter featuring the LTC7804 (MSE package), a spread spectrum or constant frequency current mode synchronous boost controller. The DC2846A generates a 24V output voltage and provides up to 6A of output current.
The 500kHz constant switching frequency operation results in a small and efficient circuit.
The main features of this board include:
- Wide input voltage range: from 6V to 24V
- Relatively high output power, up to 150W
- Extremely low quiescent current, it’s 15µA at sleep mode and as low as 1µA at shutdown
- Onboard low power bias supply
- Ability to select spread spectrum or fixed frequency
- Pulse-skipping mode, forced continuous operation or low ripple Burst Mode® operation at light loads
- Synchronization with external clock
- If VIN > VOUT, the DC2846A eliminates the usual boost topology losses by keeping the top MOSFET on continuously.
The converter provides high output voltage accuracy (typically ±2%) over a wide load range with no minimum load requirement.
The DC2846A supports two ways of biasing step-up controllers: directly from the input voltage or output rail. The third possibility is connecting voltage source to EXTVCC terminal.
The DC2846A extremely wide switching frequency range from 100kHz to 3MHz. It can be synchronized to the external clock anywhere inside this range. The spread spectrum operation is used for reducing the peak radiated and conducted noise to simplify compliance with electromagnetic interference (EMI) standards.
The DC2846A has small circuit footprint. It is a high performance and cost-effective solution for telecom, automotive and Power over Ethernet applications.
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:
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.