Date: 26/09/2012
Analog’s ADP1851 configurable DC-DC controller for high-current applications
Analog Devices (ADI) has launched the ADP1851 wide-input-range, synchronous, step-down DC-to-DC controller with voltage tracking and synchronization capability. The ADP1851 is configurable to work as a voltage-mode controller with input feed-forward or as a current-mode controller, depending on the application and customer preference. The device can be used in a range of communications networking, industrial, medical, and consumer applications.
The ADP1851 can be connected in parallel to achieve higher current delivery—up to 50 A depending on the external FETs. The ADP1851 features a synchronization input eliminating troublesome “beat” frequencies and reducing system input capacitance when multiple devices with phase-shifted synchronization are used. ADP1851 also has a tracking capability that enables controlled start-up. Simple, robust sequencing can be implemented using the precision enable and power good functions. Input range operation is from 2.75 V to 20 V and the reference accuracy is ±1% (-40 Deg C to +125 Deg C) and ±0.5% (-40 Deg C to +85 Deg C).
The ADP1851 architecture in the current-mode control detects the current during the off period to improve noise immunity utilizing the on-resistance of the low-side FET—or a series sense resistor for higher accuracy. Current mode performance is optimized by adding the externally adjustable slope compensation. With minor adjustments to external resistor settings, the ADP1851 can be configured for voltage-mode control for improved noise performance, using input line feed-forward for line rejection. The device features a selectable pulse-skip mode to improve efficiency during light load operation and an accurate current limit feature to help in sizing the selection of external components.
The ADP1851 is available in a 16-lead LFCSP (4-mm x 4-mm) package and is supported by ADI’s online ADIsimPowerTM tools.
Datasheet link: http://www.analog.com/ADP1851
Source: Analog Devices