ROHM Offers LogiCoA: The Industry’s First Analog-Digital Fusion Control Power Supply Solution

July 10, 2024

ROHM Semiconductor today announced LogiCoA™, a power supply solution for small to medium power industrial and consumer equipment (30W to 1kW class). It provides the same functionality as fully digital control power supplies at low power consumption and cost equivalent to analog power types.

Analog controlled power supplies are commonly used in industrial robotics and semiconductor manufacturing equipment that operate in the medium power range. However, in recent years these power supplies have also been required to provide a high level of reliability and precise control that make it difficult to meet market demands with analog-only configurations. On the other hand, while fully digitally controlled power supplies enable fine control and settings, they are not widely adopted in the small to medium power range due to the high power consumption and cost of the digital controller. To address this issue, ROHM developed the LogiCoA power solution that leverages the strengths of both analog and digital technologies. High performance, low power LogiCoA MCUs are utilized to facilitate control of a variety of power supply topologies.

The LogiCoA brand embodies a design philosophy of fusing digital elements to maximize the performance of analog circuits. ROHM’s LogiCoA power solution is the industry’s first^[1] “analog-digital fusion control” power supply that combines a digital control block centered around the LogiCoA MCU with analog 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 realize with an analog 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 analog control power supplies, contributing to smaller power supplies that provide greater reliability. In addition, as operation log data can be recorded in the MCU’s nonvolatile memory, it is ideal for power supplies 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 will continue to develop LogiCoA MCUs to support various power supply topologies, contributing to achieving a sustainable society by making the power supply block (which accounts for the majority of power loss in applications) more energy efficient and compact.

LogiCoA Brand

LogiCoA is a brand that embodies a design philosophy of fusing digital elements to maximize the performance of analog circuits. By combining the advantages of analog circuitry with those of digital control, it is possible to maximize the potential of circuit topologies, contributing to more efficient power utilization. As LogiCoA is a design concept that can be applied not only to the power supply field, but also to power solutions as a whole, ROHM is considering its application in future products and solutions.

LogiCoA Power Supply Reference Design

The REF66009 evaluation reference design offered on ROHM’s website allows users to verify the functionality of the LogiCoA MCU, along with the basic operation of the LogiCoA power supply solution, using a non-isolated 12V buck converter circuit. Sample software available on the reference design page makes it possible to confirm the sequence control of execution tasks and the monitoring of various parameters in the actual set using the LogiCoA001-EVK-001 reference board. For more information on the reference board, please contact a sales representative or the contact page on ROHM’s website.

Application Examples

• Industrial robots
• Semiconductor manufacturing equipment
• Gaming applications
• Supports mounting in a wide range of general industrial equipment and consumer devices (30W to 1kW)

About the LogiCoA MCU

ROHM is developing LogiCoA MCUs optimized for integrated analog-digital control, such as LogiCoA power supply solutions. Features include a built-in 3-channel analog comparator that can be linked to a timer and D/A converter that enables digital control of various parameters to support different power supply topologies.