Twelve 7A PolyPhase Synchronous Step-Down Regulators Deliver 84A

Linear Technology Corp. announces the LTC3415, a high efficiency, monolithic synchronous buck regulator using a phase lockable, constant frequency, current mode architecture. A single LTC3415 can deliver up to 7A of output current at voltages as low as 0.6V. In addition, the LTC3415's PolyPhase® operation enables multiple (up to 12 in total) LTC34515s to be run with interleaved phases while using minimal input and output capacitance.

When twelve LTC3415s are cascaded together, they can drive a single load with up to 84A of output current while current sharing equally between the units. Its input voltage range of 2.5V to 5.5V makes it suited for single cell Li-Ion battery as well as point-of-load applications. Its default switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. Combined with a 5mm x 7mm QFN package, it provides a compact high-current power conversion solution.

The LTC3415 uses internal switches with an RDS(ON) of only 0.025 ohm (N-Channel) and 0.032 ohm (P-Channel) to deliver efficiencies as high as 96%. It also utilizes low dropout 100% duty cycle operation to allow output voltages equal to Vin. Selectable Burst Mode® operation offers no load quiescent current of only 450µA, and less than 1µA in shutdown.

If the application is noise sensitive, the LTC3415 can be configured to skip pulses, provide forced continuous operation or utilize spread spectrum frequency switching to reduce noise and potential RF interference. Additionally, the LTC3415 can be externally synchronized from 750kHz to 2.25MHz to further reduce noise. Other features include a Power Good voltage monitor, output tracking and margining capability plus thermal protection.

The LTC3415 is available from stock in a 38-pin, 5mm x 7mm QFN package. Pricing starts at $6.50 each in lots of 1,000 pieces.