DC/DC Controller operates at 97% efficiency without heat sink.
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Press Release Summary:
Replacing boost diode with N-Channel MOSFET, Model LTC3788/-1 eliminates heat sink normally required in medium to high power boost converters. Synchronous step-up switching controller can produce 24 V at 5 A output with up to 97% efficiency. Operating from input voltage of 4.5-38 V during start-up, device maintains operation down to 2.5 V after start-up and can regulate output voltage as high as 60 V. It has phase-lockable frequency from 75-850 kHz or selectable fixed frequency from 50-900 kHz.
Original Press Release:
Dual Output, High Power 60V Synchronous Boost Controller Eliminates Heat Sink with 97% Efficiency
MILPITAS, CA - - Linear Technology Corporation announces the LTC3788/-1, a dual output, high power synchronous step-up switching DC/DC controller that replaces the boost diode with a high efficiency N-Channel MOSFET. This eliminates the heat sink normally required in medium to high power boost converters. The LTC3788/-1 can produce a 24V at 5A output with up to 97% efficiency, making it ideal for high power automotive audio amplifiers, industrial and medical applications where a step-up DC/DC converter must deliver high power with low heat dissipation in a small solution size.
The LTC3788/-1 operates from an input voltage ranging from 4.5V to 38V during start-up, maintains operation down to 2.5V after start-up and can regulate an output voltage as high as 60V. The powerful 1.5Ohm onboard N-channel MOSFET gate drivers are capable of slewing large MOSFET gates quickly, minimizing transition losses and allowing for up to a 10A per channel output current. In addition, the LTC3788/-1 draws only 125µA when one output is active and only 200µA when both outputs are enabled.
The constant frequency current mode architecture allows for paralleled outputs. The LTC3788 includes a clock output, phase modulation (for multiphase applications), two separate power good outputs and an adjustable current limit. The LTC3788/-1 has a phase-lockable frequency from 75kHz to 850kHz or a selectable fixed frequency from 50kHz to 900kHz. It has adjustable cycle-by-cycle current limit protection and uses either a sense resistor or monitors the voltage drop across the inductor (DCR) for current sensing. In applications where the input voltage may sometimes exceed the regulated output voltage, the LTC3788/-1 is able to keep the synchronous MOSFET on continuously so that the output voltage follows the input voltage with minimal power loss. Furthermore, the LTC3788/-1 has adjustable soft-start and maintains ±1% reference voltage accuracy over an operating temperature range of -40ºC to 125ºC.
The LTC3788-1 is available in an SSOP-28 package and the LTC3788 is housed in a 32-lead 5mm x 5mm QFN. The 1,000-piece price starts at $4.12 each. Both versions are available from stock. For more information, visit www.linear.com.
Summary of Features: LTC3788/-1
Up to 97% Efficiency
Eliminates Heat Sink in Medium to High Power Boost Converters
Up to 60V VOUT Operation
Wide VIN Ranging from 4.5V to 38V, Maintains Operation down to 2.5V After Start-Up
Powerful 1.5 Ohm Gate Drivers
100% Duty Cycle Capability for Synchronous MOSFET
Phase Lockable Frequency from 75kHz to 850kHz
Programmable Fixed Frequency from 50kHz to 900kHz
RSENSE or Inductor DCR Current Sensing
Current Mode Control
±1% Reference Voltage Accuracy over -40ºC to +125ºC
Programmable Soft-Start
Phase Modulation
Power Good Outputs
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits, was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major public companies in 2000. Linear Technology products include high performance amplifiers, comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery chargers, data converters, communications interface circuits, RF signal conditioning circuits, µModule® products, and many other analog functions. Applications for Linear Technology's high performance circuits include telecommunications, cellular telephones, networking products such as optical switches, notebook and desktop computers, computer peripherals, video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer products such as digital cameras and MP3 players, complex medical devices, automotive electronics, factory automation, process control, and military and space systems.
LT, LTC, LTM, µModule and are registered trademarks of Linear Technology Corp. All other trademarks are the property of their respective owners.
North America and General Information
John Hamburger
Tel: (408) 432-1900 ext. 2419
jhamburger@linear.com
Doug Dickinson
Tel: (408) 432 1900 ext. 2233
ddickinson@linear.com
