New Industry Products

ROHM’s New Nano Cap Technology Significantly Reduces Capacitance in Auto Applications

July 16, 2020 by Antonio Anzaldua Jr.

ROHM has added a third Nano power supply technology, Nano Cap, which will reduce the number of external capacitors required for linear regulators in automotive applications.

ROHM Semiconductor is a Japanese electronic parts manufacturer that specializes in automotive and industrial industries. Originally ROHM manufactured resistors for various applications, now, ROHM is a leading manufacturer of power devices for EVs and consumer products. 


Image used courtesy of ROHM Semiconductor.
Image used courtesy of ROHM Semiconductor.


In 2018, ROHM introduced the development of ultra-high-speed pulse control technology Nano Pulse Control and ultra-low current technology Nano Energy. ROHM had deemed it a series of Nano-power supply technology that would target reducing PCB footprint from needing external electrical components. As of late June, ROHM has announced an expansion of its Nano-series by unveiling the development of a Nano Cap power supply technology that ensures stable control of power supply circuits.


ROHM’s Power Supply Technology 

ROHM has established Nano power supply technologies that are centered around power supply ICs. Nano Pulse Control is a fast pulse controller for power supply ICs, it achieves a switching ‘ON’ time in a matter of nanoseconds. This allows for conversions from high to low voltages with only using a single IC. Ideal for 48V power supply applications such as hybrid vehicles and industrial robots. 

Nano energy enables long term drive in battery-equipped devices. It provides ultra-light loads with a current consumption of 180nA, and 90% power efficiency through a current range of 10uA to 500mA. This Nano-series was designed to have power devices to lower the IC’s power consumption.


Nano Cap technology is planned to be used not only to linear regulators, but Op-amps, LED drivers, and other analog ICs as well
Nano Cap technology is planned to be used not only to linear regulators, but Op-amps, LED drivers, and other analog ICs as well. Image used courtesy of ROHM Semiconductor.


Nano Cap is the third addition to the Nano-series which provides stable control of linear regulator output by improving response in analog circuits. Making it possible to reduce the output capacitance to less than 1/10th over standard solutions. Given an automotive industry requirement for output voltage fluctuation of ±5.0% max, with respect to 50mA load current fluctuation with 100nF capacitance. Nano Cap equipped chips to achieve a stable operation of ±3.6% in the evaluations, compared with conventional linear regulators whose output voltage can vary by as much as ±15.6%.


Non-Reliant on Capacitors 

Conventional power supplies are coupled with external components such as capacitors that can be found at the output side of linear regulators. Nano Cap will eliminate the number of capacitors on the output side of the power supply and decrease the overall design load.


How conventional power supply configurations compare to Nano Cap technology
How conventional power supply configurations compare to Nano Cap technology. Image used courtesy of ROHM Semiconductor.


The comparison shown in the Nano Cap Solution is proof of how PCBs will decrease in size; the traditional power supply design method requires an additional capacitor in-line with a linear regulator to provide stable operation. By utilizing Nano Cap technologies, ROHM is able to present the same level of control optimization with fewer external components. 


Avoiding Parasitic Capacitances In Automotive Designs

Sustainable energy consumption is what leads automotive applications to be more efficient and robust for advancing in EVs and autonomous driving. These applications typically require a variety of voltage sources that are stabilized by capacitors. In most cases, there will be a need for external components for each power supply.

Even though capacitors are still used for linear regulators designs, the Nano Cap power supply does shorten the external components list, minimize design load, and decrease the PCB’s footprint. Expect ROHM to continue to evolve its Nano-technology, which may eventually lead to the elimination of capacitors entirely.