Overview

Product Details

Demonstration circuit 2938A is a dual output nonisolated synchronous step-down converter that drives all N-channel gallium nitride (GaN) FET power stages. DC2938A features the LTC®7890, a low quiescent current high frequency (programmable fixed frequency from 100kHz up to 3MHz) dual step-down DC/DC synchronous controller, with dedicated driver feature for GaN FET housed in a small 6mm × 6mm QFN package.

The DC2938A operates over an input voltage range from 30V to 72V, while the LTC7890 can operate up to 100V. The DC2938A demo board produces two outputs: 5V and 12V with up to 20A output, respectively. DC2938A is configured with a sense resistor for current sensing. A mode selector allows the DC2938A to operate in forced continuous operation, pulse-skipping or Burst Mode® operation during light loads. DTCA and DTCB selector provides easy adjustment of the dead time to improve efficiency or to tailor the application. DRVSET and DRVUV selector offers option to choose drive voltage from 4V to 5.5V to optimize performance.

The EXTVCC pin permits the LTC7890 to be powered from the output of the switching regulator or other available source, reducing power dissipation, and improving efficiency. Please refer to the LTC7890 data sheet for a complete description of the part operation and application information.

Applicable Parts

Documentation & Resources