Configurable Buck DC/DCs Deliver a Total of 8A from 2 to 4 Independent Outputs for Power System Flexibility

Linear Technology LTC3371

Linear Technology Corporation announces the LTC3371, a highly integrated general-purpose power management solution for systems requiring multiple low voltage power supplies. The device features four synchronous buck converters, each powered from independent 2.25 V to 5.5 V inputs, and each configurable to share up to four of eight available 1 A power stages. With eight unique output current configurations, the LTC3371 provides substantial flexibility and ease of reuse across many different applications. The device is ideal for a wide variety of multichannel industrial, automotive, communications and distributed power systems.

Linear Technology - LTC3371

The LTC3371's buck power stages can be connected in parallel by simply combining their respective VIN and SW pins and programming the desired configuration on the C1-C3 pins. Up to four adjacent power stages can be combined on a single channel, resulting in eight unique output configurations ranging from a quad 2 A buck to a dual 4 A buck. A single inductor may be used for each buck regulator, and any unused power stages may be added to one of the high power channels for improved overall efficiency.

The LTC3371's precision enable pin thresholds, independent power-on reset outputs, watchdog timer and die temperature monitor, provide flexible and reliable power-up sequencing and system monitoring. All of the switching regulators are internally compensated and need only external feedback resistors to set the output voltages. The common buck switching frequency can be programmed with an external resistor, synchronized to an external oscillator or set to a default internal 2 MHz clock. The switching regulators may be programmed to operate either in Burst Mode® operation for high efficiency at light loads or in forced continuous PWM mode for lowest noise at light loads. The bucks are phased in 90° steps to reduce noise and input ripple, have forward and reverse current limiting, soft-start to limit inrush current during start-up, and short-circuit protection.

The LTC3371 is available from stock in thermally enhanced 38 pin packages: a low profile 5 mm × 7 mm QFN and TSSOP. E- and I-grades are specified over an operating junction temperature range of –40 °C to 125 °C, and the H-grade features operation from –40 °C to 150 °C. 1000-piece pricing starts at $4.15 each for the E-grade.

Summary of Features: LTC3371

  • 8 × 1 A Buck Power Stages Configurable as 2, 3 or 4 Output Channels
  • 8 Unique Output Configurations (1 A to 4 A Per Channel)
  • Independent VIN Supplies for Each DC/DC (2.25 V to 5.5 V)
  • Low No Load Supply Current:
    • 15 μA in Shutdown (All Channels Off)
    • 68 μA One Channel Active in Burst Mode® Operation
    • 18 μA Per Additional Channel
  • Precision Enable Pin Thresholds for Autonomous Sequencing
  • 1 MHz to 3 MHz RT Programmable Frequency (2 MHz Default) or PLL Synchronization
  • Temp Monitor Indicates Die Junction Temperature
  • CT Programmed Watchdog Timer
  • Independent /RST {надчеркивание} Pins Indicate When Each Buck Is in Regulation
  • 38 Lead 5 mm × 7 mm QFN & TSSOP Packages
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