Attention to Internet Explorer users: ROHM website does not recommend browsing in IE 11. Please use latest browser to ensure the best performance on ROHM website.
ROHM's innovative 'Nano' power supply technologies achieve
breakthrough energy savings and miniaturization
Ultra-high-speed pulse control technology Nano Pulse Control™
Ultra-low-current technology Nano Energy™
Extremely stable control technology Nano Cap™
What is ‘Nano’ Power Supply Technology?
Revolutionary Nano power supply technologies that leverage ROHM's analog expertise cultivated over many years to achieve greater miniaturization and energy savings. The Nano power supply technologies, developed using our integrated production system in which all processes, from development to products, are performed in-house, consists of three power supply technologies designed to meet current and future market needs.
Nano Cap™ power supply technology that ensures stable control of power supply circuits in the automotive and industrial fields – even with ultra-small capacitances in the magnitude of nF.
Convert high voltages to low voltages using a single IC. Achieve simpler, more compact systems.
Development Background
The proliferation of hybrid and electric vehicles in response to the growing need to curb CO2 emissions on a global scale has brought attention to mild hybrid vehicles that provide better cost performance than full hybrids. Mild hybrid systems utilize a 48V lithium ion battery to deliver greater efficiency over conventional 12V power supplies. However, the many ECUs used in many vehicle systems demand lower drive voltages, typically 3.3V but as low as 2.5V.
To convert 48V to 3.3V at 2MHz (to prevent interference with the AM radio band) conventional solutions employ 2 stages (two ICs), the first to step-down to an intermediate voltage such as 12V. In 48V systems it is also necessary support step-down operation from a maximum voltage of 60V to 2.5V, requiring an extremely high step-down ratio of 24:1 when using a single chip.
Technology Development and Commercialization
At ROHM, we challenged ourselves with the extremely high goal of developing ultra-high-speed pulse control technology (Nano Pulse Control™) for monolithic (single-chip) DC-DC converters. As a result, we were able to reduce the switching ON time to an unprecedented 9ns, the smallest in the world (ROHM Jul. 2017 study) and a breakthrough accomplishment considering that the previous ON time is around 120ns. Another major benefit of this technology is stable control at extremely narrow pulse widths.
Development involved breaking from convention by leveraging proprietary analog design technology and power supply process expertise along with our vertically integrated production system. As a result, step-down operation from 60V to 2.5V is achieved through the BD9V100MUF monolithic buck DC-DC converter IC with integrated MOSFET. In 2023, we evolved Nano Pulse Control™ and successfully improve the control pulse width from 9ns to 2ns.
A world of possibilities
Developing a DC-DC converter IC capable of stepping down from 60V to 2.5V on a single chip significantly reduces the number of parts compared to conventional 2-chip systems. In particular, at higher frequencies it becomes possible to greatly reduce the size of the coil.
This will allow users to simplify system design, reduce application size, and at the same time decrease costs. For example, minimizing the size and costs of 48V power supply systems used for mild hybrid cars, industrial robots, and base station sub-power supplies is expected to contribute to the advancement of society.
In addition to the BD9V100MUF, ROHM will continue to develop products incorporating Nano Pulse Control™ to meet customer demands.
Topic
ROHM Establishes Ultra-High-Speed Drive Control IC Technology that Maximizes GaN Device Performance
While the adoption of GaN devices has expanded due to their superior high-speed switching characteristics, the speed of control ICs, which are responsible for directing the driving of these devices, has become an issue. In response, ROHM has further evolved Nano Pulse Control™, succeeding in significantly improving the control pulse width from the conventional 9ns to an industry-best* 2ns. This has led to the establishment of ultra-high speed drive control IC technology that maximizes the performance of GaN devices. ROHM is currently developing 100V input voltage 1ch DC-DC controller ICs using this technology.
Enables long-term drive in battery-equipped devices.
Development Background
In the electronic equipment field, in addition to the increasing functionality of smartphones and widespread use of wearables, the introduction of IoT devices that can operate and communicate wirelessly between devices without human intervention is attracting attention. In many cases these devices are driven by batteries, making it necessary to reduce power consumption. And although improving design and securing space for integrating new functions are progressing, miniaturization is also an important factor, leading to smaller drive batteries, but there is a large number of devices where maintenance (i.e. changing batteries) cannot be carried out regularly, especially in the IoT field, driving the demand to enable long-term operation (10 years) on a single coin battery.
In response to these market trends and themes, ROHM began developing technologies to significantly reduce IC power consumption (at 2015). At the start, the lowest current consumption in the industry for power supply ICs was 360nA. This provided a baseline for our efforts.
Technology Development and Commercialization
When simply considering reducing current consumption, the first option is to raise the resistance value of the circuit, but this can lead to problems such as element current leakage, increased sensitivity to noise, and reduced response speed. In response, ROHM developed Nano Energy™, a breakthrough technology that decreases current consumption during ultra-light loads while minimizing the ensuing trade-off.
This technology was used to develop the BD70522GUL DC-DC converter with quiescent current consumption of 180nA, which delivers twice the battery drive time of conventional products. In addition, high 90% power efficiency is enabled in the widest current range in the industry: 10uA to 500mA. ROHM was able to achieve these characteristics by leveraging proprietary circuit design, layout, and process technologies with its original vertically integrated production system.
A world of possibilities
Dramatic reductions in the power consumption of power supply ICs in the IoT field has brought about a demand to achieve 10-year drive on a single coin battery. This allows for a reduction in the amount of labor and costs required for device maintenance by enabling long-term drive with small batteries even in wearables that are becoming increasingly compact and multifunctional.
In addition, it will be possible to continue operation even in extremely low-power environments, such as energy harvesting systems that generate small amounts of electricity from light, heat, and vibration (which is expected to see increased adoption in a variety of fields).
At ROHM, Nano Energy™ will be used as a core technology to expand its lineup of power supply ICs to meet a range of customer requirements.
Topic
Battery Management Reference Design for Advanced Rechargeable Batteries
Nano Energy™ technology is ideally suited for energy harvesting using solar cells and state-of-the-art rechargeable batteries. ROHM is working with battery manufacturers to strengthen the development and supply of reference designs for battery management systems (BMS) in IoT devices. One example is the REFLVBMS00x reference design that consists of a power supply IC equipped with Nano Energy™ along with the most advanced batteries from various battery manufacturers, resulting in an ultra-low power supply solution that also includes a charge control IC for managing the charging, monitoring, and discharging of the batteries to achieve an ultra-high efficiency energy storage unit. A voltage detector (reset IC) is mounted as well to detect anomaly voltages utilizing Nano Energy™ for ultra-low quiescent current, providing efficient power supply functions for user applications.
Ensures stable control of power supply circuits in the automotive and industrial fields – even with ultra-small capacitances in the magnitude of nF.
Development Background
The growing awareness for sustainable energy consumption has led to greater electrification in a variety of applications. Especially in the automotive field, the number of electrical components continues to increase due to technological innovations spurred by advances in EVs and autonomous driving. Each of these electrical applications requires a variety of voltage sources, all of them stabilized by capacitors. This results in an increasing demand of external components, increasing PCB sizes and adding cost to the Bill of Material.
To address this issue, power supply circuits are requiring power supply ICs (LDO regulators) that can operate even with small output capacitors, but reducing capacitance increases the risk that the output voltage of the IC will become unstable and oscillate in response to input or load variations. As such, achieving stable operation required by applications (e.g. limiting output voltage fluctuations to within ±5% during load fluctuations) is possible down to 1µF, but to ensure stable operation in the nF range and below an unprecedented technological breakthrough was necessary.
Technology Development and Commercialization
Nano Cap™ provides stable control of linear regulator output by improving response in analog circuits while minimizing parasitic factors related to wiring and amplifiers, making it possible to reduce the output capacitance to less than 1/10th over conventional solutions. As a result, circuits composed of a linear regulator and MCU which usually require a 1µF capacitor at the output of the linear regulator and a 100nF at the input of the MCU as mentioned above, ROHM’s Nano Cap™ linear regulator technology achieve stable operation using just one 100nF capacitor at the MCU side. What’s more, even when high circuit reliability is required, such as in automotive applications, stable operation is possible by reducing the output capacitor of the LDO to around 100nF (much less than 1µF). This not only decreases the size of components and substrates, but also reduces the number of design resources by supporting a wider range of capacitances.
A world of possibilities
Incorporating Nano Cap™ ultra-stable control technology in the BD9xxN1 of LDOs enables support for output capacitances as low as 100nF, which is less than 1/10th that of general products, ensuring stable operation required by applications (output voltage variation within 100mV: 1mA ⇔ 50mA/1µs load current fluctuation) even when the input voltage or load current fluctuates. This provides compatibility with a wide range of output capacitors, including not only common µF-order compact MLCCs (Multi-Layer Ceramic Capacitors) and large capacitance electrolytic capacitors, but also ultra-compact MLCCs down to 1µF or less in the 0603 size which were previously not stable enough and couldn’t withstand actual use.
ROHM is further accelerating product deployment of Nano Cap™ technology established in 2020 to solve stability issues related to capacitors in various analog circuits by deploying in the internal circuitry of LDO regulators, Op Amps, and other products.
Nano Pulse Control™, Nano Energy™, Nano Cap™ are trademarks or a registered trademarks of ROHM Co., Ltd.
EcoGaN™ is a trademark or a registered trademark of ROHM Co., Ltd.
