New Industry Products

Analog Devices DC-DC Switching Controller Features Current-mode and Voltage-mode Options for High-current Applications

June 11, 2012 by Jeff Shepard

Analog Devices, Inc. (ADI) introduced the ADP1853 wide-input-range, synchronous, step-down dc-dc controller with voltage tracking and advanced clock synchronization capability. The versatile ADP1853 can be configured as a voltage-mode controller with input feed-forward or as a current-mode controller, depending on the application and customer preference. The ADP1853 has clock-out and synchronization input to ensure 180-degree phase-shifted synchronization, eliminating troublesome "beat" frequencies and reducing system input capacitance when multiple devices are used.

The new controller’s tracking capability enables controlled start-up. Simple, robust sequencing can be implemented using the precision enable and power-good functions. The ADP1853 can be connected in parallel to achieve higher current delivery—up to 50 A depending on the external FETs. The ADP1853 is designed for high-efficiency, high-current, fast-transient, point-of-load applications in a broad range of communications networking, industrial, medical, and consumer applications.

In current-mode control, the ADP1853 architecture detects the current during the off period to improve noise immunity using the on-resistance of the low-side FET -- or a series sense resistor for higher accuracy. Externally adjustable slope compensation is added to optimize performance in current mode. With minor adjustments to external resistor settings, the ADP1853 can be configured for voltage-mode control, using input-line feed-forward for excellent line rejection. The ADP1853 has a selectable pulse-skip mode to increase efficiency during light load operation. The device also has an accurate current limit, which allows optimal sizing selection of external components to optimize valuable PCB space. The ADP1853 is accompanied by ADI’s online ADIsimPower™ tools for ease of use and reduced design time.

ADP1853 Key Features and Benefits include:

-- Configurable as voltage-mode or current-mode controller depending on the application and customer preference

-- Clock-out function allows the device to operate as a system synchronization master to other ADP1853 devices eliminating potential "beat" frequencies and reducing input current ripple using phase-shift synchronization.

-- Power-good and precision-enable facilitate simple, robust sequencing and health detection

-- Reference accuracy ±1% over the temperature range from –40 to +125°C and ±0.5% from –40 to +85°C.

-- Selectable pulse-skip mode for energy saving at light load

-- Parallel connection to reach higher load-current capability in dual-phase mode

-- Easy to Use ADIsimPower™ tool reduces design time

The ADP1853ACPZ-R7 is priced (per 1,000) at $1.20.

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