DC/DC Step-Down Converter has PLL and output tracking.

Press Release Summary:




Utilizing dual, 180º output of phase controllers, LTC3828 step-down synchronous switching controller features integrated tracking for sequencing multiple voltage rails and PolyPhase® operation. It converts 4.5-28 V input voltage to 2 regulated output voltages, adjustable from 0.8 V up to 99% of input voltage. Operating at 3, 4, or 6 phases, IC has constant 550 kHz frequency current mode architecture and can also be locked to 260-550 kHz clock to reduce EMI.



Original Press Release:



Dual PolyPhase DC/DC Step-Down Controller with PLL & Output Tracking



MILPITAS, CA - May 23, 2005 - Linear Technology Corporation introduces the LTC3828, a dual step-down synchronous switching controller with integrated tracking for sequencing multiple voltage rails, phase-locked loop (PLL) for precision synchronization and PolyPhase® operation for reducing input capacitance. The LTC3828 has a unique capability to daisy chain to multiple LTC3828s or other DC/DC converters to provide tracking for more than two voltages while operating at 3, 4 or 6 phases. The IC has a constant 550kHz frequency current mode architecture and can also be locked to a 260kHz to 550kHz clock to reduce EMI at sensitive frequencies.

The LTC3828 is used to convert 4.5V to 28V (30VMAX) input voltage to two regulated output voltages, adjustable from 0.8V to as high as 99% of the value of the input voltage. The LTC3828's wide operating voltage and unique integrated functions enable the design of compact multiple output power supplies in applications such as single-board computers, industrial equipment, automotive electronics and FPGA-based systems.

The LTC3828 uses a constant frequency, current mode all N-channel MOSFET synchronous architecture with the two control channels operating 180º out of phase. A clock output pin enables synchronization of multiple controllers. The IC allows the user to program how the channel outputs ramp up and down. Both coincident and ratiometric tracking are supported. Moreover, high current gate drivers allow high power density solutions. Powering difficult loads such as starting with pre-biased outputs, common when power ASICS, is supported by preventing reverse inductor currents and disabling current fold back during start-up.

The LTC3828 is rated for operation from -40ºC to 85ºC and is offered in 28-lead SSOP and 5mm x 5mm QFN packages. 1,000-piece pricing starts at $4.65 each.

Summary of Features: LTC3828

o Dual, 180º Output of Phase Controllers Reduce Noise & Input Capacitance

o Tracking & Synchronization of Two or More Supplies

o Constant frequency Current Mode Operation for Low Noise & Excellent Line & Load Regulation

o Clock Output for 3-, 4-, or 6-phase Operation

o Output Overvoltage Protection

o No Reverse Current at Start-Up Safely Powers ASICS

o Strong Gate Drivers

COMPANY BACKGROUND: Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. 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, 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.

For more information, contact:
Doug Dickinson, Media Relations Manager
Linear Technology Corporation
1630 McCarthy Boulevard
Milpitas, CA 95035-7417
ddickinson@linear.com
408-432-1900

Note: LT, LTC and are registered trademarks and VLDO is a trademark of Linear Technology Corp.

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