Special purpose voltage regulators are devices for converting an input voltage into an output voltage and maintaining the output voltage at a set value under dynamic load changes and source voltage changes. The ability of the device to maintain a stable load voltage is referred to as regulation. Special purpose regulators are regulators that are dedicated to particular applications, and nay have some different characteristics or functionality specific to the needs of the application.

 

There are special purpose voltage regulators available for automotive applications. Because automotive applications involve safety concerns, in many cases what makes these devices special is their compliance with Automotive Safety Council standards, for example Failure Mechanism Based Stress Qualification for Integrated Circuits (AEC – Q100). Such standards must be complied with to get approval for sale, and testing can be quite expensive. As a result not all integrated circuits are qualified for use and devices can be higher priced. A typical example of this would be multi-voltage LCD voltage regulators, where the devices need to comply with higher vibration, electrostatic discharge (ESD) and thermal characteristics relative to their commercial grade counterparts.

 

Some microprocessor system manufacturers – in particular, those that sell a microprocessor system that targets mobile or portable applications have special purpose multi-voltage regulators that provide a complete solution for the product. They include special functionality like control of the order of power up of each voltage rail, push button ON/OFF interfaces, and can be designed to comply with the needs of a particular power management software system – having a serial interface that can report to the microprocessor supply states and all the processor control.  They may have the battery-charging capability and may also allow for external powering capabilities, for example being powered by or powering devices over USB.

 

Special purpose voltage regulators are available for devices like FPGAs to provide the high number of voltage rails that need to be supported. There are other voltage converters that are not only able to source current as a power supply but also sink current as an active load. These are particularly important acting as termination voltage references in high-speed parallel buses – like those used in DDR2, DDR3 memories. In a similar vane, bidirectional current DC controllers are designed to allow for cell balancing in battery stacks by monitoring the current and voltage of each battery during charging and reacting to ensure that the charging is balanced despite the variation in cell characteristics.