In recent years, the ongoing digitization of all types of equipment has increased the number of electronic components, which in turn has driven the demand to reduce the number of capacitors used for circuit stabilization in order to reduce both size and bill of materials (BOM). This requires integrated power supply circuits that can achieve stable operation with small capacitors. However, until now, achieving stable operation in applications with output capacitances of 1 µF or less has been challenging.
To meet these needs, ROHM developed the Nano Cap™ ultrastable control technology for power integrated circuits in 2020. Leveraging this technology allows designers to develop LDO regulators that ensure stable operation even with ultra-small output capacitances at the nanoscale.
This allows for an output capacitance of 100 nF — less than 1/10 of the value of standard products — ensuring the stable operation required by applications (output voltage variation within a range of 100 mV: the condition is a load current variation of 1 mA ⇔ 50 mA/1 µs), even when the input voltage and load current fluctuate.
On the other hand, in addition to common µF-order MLCCs (multilayer ceramic capacitors) and large capacitance electrolytic capacitors, ROHM's new regulators can handle an ultrawide range of output capacitances down to 1 µF or lower in the ultracompact 0603/0402 size (which in the past had not been stable enough to be used), contributing not only to the miniaturization of components and boards, but also to a reduction in the design resources required by supporting a wider range of capacitor conditions.
In the future, ROHM will expand its LDO regulator series with integrated Nano Cap™ technology to 22 models in various output voltages and packages by the end of fiscal year 2022. In 2023, an additional 24 models will be added to support an output current of 500 mA, bringing the total to 46 products by the end of fiscal year 2023 and providing even greater applicability.
What is Nano Cap™ technology?
Nano Cap™ refers to ultra-stable control technology achieved by combining expertise in advanced analog design, encompassing circuit design, processes, and layout, using ROHM's vertically integrated production system. Stable control eliminates the problem of unstable operation related to capacitors in analog circuits, helping to reduce design resources for a wide range of applications in automotive, industrial equipment, consumer electronics, and other sectors. https://www.rohm.com/support/nano 
New Product Details:
The new BD9xxN1 series of automotive primary LDOs meets the essential requirements of automotive products, such as operation at temperatures exceeding 125°C, qualification according to the AEC-Q100 automotive reliability standard, and input voltages above 40 V for the primary power supply. The incorporation of ROHM's Nano Cap™ ultra-stable control technology supports an output capacitance of 100 nF, which is less than 1/10th the value of standard products, ensuring the stable operation required by applications (output voltage variation within a range of 100 mV: load current variation of 1 mA to 50 mA/1 µs) even when the input voltage and load current fluctuate. This delivers high performance with a well-balanced output capacitance range and response characteristics.
Application examples
Powertrain (i.e., fuel injection) and tire pressure monitoring systems (TPMS)
Body systems (e.g., body control modules)
ADAS (e.g., domain controllers, ECU, zonal processing)
Infotainment, including instrument clusters and head-up displays (HUDs)
Suitable for a wide range of applications in addition to automotive primary power systems.
Availability: immediate (samples), August 2022 (in mass production)
