Linear Technology introduces the LTC2925, a power supply tracking controller that provides a variety of power-up and power-down profiles for systems with up to four supplies. By configuring a few resistors, the IC ramps the supplies up and down together with voltage offsets, time delays or different ramp rates.
The LTC2925 features power-up timeout circuitry that turns off the supplies if an external voltage monitor fails to indicate that all supplies have entered regulation within a specified time-out period. With its versatile yet simple to configure power supply tracking and sequencing capabilities, the LTC2925 is suitable for any application with multiple power supply systems, such as servers, base stations, storage area network and central office applications.
The IC introduces currents into the feedback nodes of independent supplies, causing their outputs to track without inserting any pass element losses. A single LTC2925 controls three of the four supplies without a series MOSFET. For systems that require a fourth supply or when a supply does not allow direct access to its feedback resistors, a series FET controls the fourth. When using a FET, an electronic circuit breaker provides protection from short-circuit conditions. An internal remote feedback switch compensates for the voltage drop across the FET and the current sense resistor.
The LTC2925 is available in narrow 24-pin SSOP and tiny 24-lead DFN packages. It is offered in both the commercial and industrial temperature ranges and pricing starts at $3.75 each for 1,000 pc quantities.
For more information, visit www.linear.com.