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72V Fixed-Ratio DC/DC Controller Eliminates Power Inductor & Delivers 500W in Non-Isolated Intermediate Bus Converter Applications

MILPITAS, CA & NORWOOD, MA – June 20, 2017 – Analog Devices, Inc., which recently acquired Linear Technology Corporation, announces the LTC7820, a high power fixed ratio charge pump DC/DC controller that eliminates the power inductor in a non-isolated intermediate bus converter, allowing up to a 50% reduction in circuit size and up to 4000W/in³ power density. The LTC7820 drives external MOSFETs in voltage divider, doubler or inverter configurations with an efficiency of up to 99%. Its open loop fixed duty is ideal for non-isolated intermediate bus applications in power distribution, datacom, telecom, high-end computing and industrial systems.

The LTC7820 operates over a 6V to 72V (80V abs max) input voltage range and can produce output currents in multiple 10s of amps, depending on the topology and choice of external components. It can be configured for a 2:1 step-down ratio from an input voltage up to 72V. Two of the LTC7820 IC’s can be cascaded for a 4:1 step-down ratio. For even higher step-down ratios, such as a 6:1, the Dickson converter topology is recommended and is ideal for 54V input to a 9V outputs, requiring only a single LTC7820. The LTC7820 can also be configured for a 1:2 step-up ratio or a 1:1 inverter ratio from an input voltage as high as 36V. External MOSFETs switch at a fixed frequency, programmable from 100kHz to 1MHz. The LTC7820’s powerful 1.1Ω N-channel MOSFET gate drivers maximize efficiency and can drive multiple MOSFETs in parallel for higher power applications.

The LTC7820 monitors system voltage, current and temperature for faults, and uses a sense resistor for overcurrent protection. It stops switching and pulls the /FAULT pin low when a fault condition occurs. An onboard timer can be set for appropriate restart/retry times. The EXTVCC pin permits the LTC7820 to be powered from the lower voltage output of the converter or other available sources up to 40V, reducing power dissipation and improving efficiency. Additional features include soft switching for low EMI, a power good output signal, undervoltage lockout and internal charge balance circuitry.

The LTC7820 is available in a 4mm x 5mm QFN-28 package. Extended and industrial temperature versions are available from –40 to 125°C. The 1,000-piece price starts at $4.70 each. For more information, visit www.linear.com/product/LTC7820.

Summary of Features: LTC7820

Wide VIN Range: 6V to 72V, 80V abs max
Up to 4000W/in³ Power Density
Up to 99% Efficiency
Step-Down: 2:1 Ratio from VIN Up to 72V
Dickson Converter Topology for 6:1 Step-Down Ratio
Step-Up: 1:2 Ratio from VIN Up to 36V
Inverter: 1:1 Ratio from VIN Up to 36V
Delivers Up to 500W
Operating Frequency from 100kHz to 1MHz
Soft Switching Topology for Low EMI
Quad Powerful N-Channel MOSFET Gate Drivers
Input Current Sensing & Overcurrent Protection
Short-Circuit Protection with Programmable Timer & Retry
Power Good Output Signal
Available in a 4mm x 5mm 28-Pin QFN Package

Analog Devices just got more Powerful. On March 10, Analog Devices acquired Linear Technology, creating the premier high performance analog company. More info at http://lt.linear.com/07c

About Analog Devices

Analog Devices (NASDAQ: ADI) is the leading global high-performance analog technology company dedicated to solving the toughest engineering challenges. We enable our customers to interpret the world around us by intelligently bridging the physical and digital with unmatched technologies that sense, measure, power, connect and interpret. Visit http://www.analog.com.

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