Analogue controlled power supplies are commonly used in industrial robotics and semiconductor manufacturing equipment that operate in the medium power range.
In recent years, however, these power supplies are also required to provide a higher level of reliability and more precise control that’s made it increasingly difficult to meet market demands with analogue-only configurations. While fully digitally controlled power supplies enable fine control and settings, they have not been widely adopted in the small to medium power range due to both the high-power consumption and cost of the digital controller.
To address this, ROHM has developed the LogiCoA power solution that leverages the strengths of both analogue and digital technologies to control a variety of power supply topologies.
LogiCoA solutions combine digital elements to maximise the performance of analogue circuits and are the industry’s first “analogue-digital fusion control” power supply that combines a digital control block centred around the LogiCoA MCU with analogue circuitry comprised of silicon MOSFETs and other power devices.
In a fully digital control power supply, the functions handled by digital controllers such as high-speed CPUs or DSPs can be processed by low-bit MCUs, making it possible to achieve increased functionality that is difficult to realise with an analogue control power supply at low power consumption and cost. This solution allows for the correction of performance variations in peripheral components according to the power supply circuit by storing various settings such as current and voltage values in the LogiCoA MCU.
As a result, there is no need to consider design margins unlike with analogue control power supplies, contributing to smaller power supplies that can provide improved levels of reliability. On top, as operation log data can be recorded in the MCU's nonvolatile memory, it is suitable for power supplies used in industrial equipment that require logging as a backup in case of malfunction.
The evaluation reference design REF66009 allows users to experience the LogiCoA power supply solution in a non-isolated buck converter circuit. Various tools necessary for evaluation are also offered, including circuit diagrams, PCB layouts, parts lists, sample software, and support documents, while actual device evaluation is possible using the optional LogiCoA001-EVK-001 evaluation board.
Going forward, ROHM said that it will continue to develop LogiCoA MCUs to support various power supply topologies.
