These days, as electronic products become smaller, it becomes more difficult to mount electronic components on a limited mounting area, which makes designers pay attention to designing and wiring a DC/DC converter board, especially when they cannot construct a recommended pattern due to limited mounting area. In addition, they need to consider the countermeasures against radiation noise generated from a DC/DC switching regulator for electronic systems using electromagnetic waves.

The RM590 series is a module which contains a synchronous buck DC/DC switching regulator with oscillator frequency of 6 MHz and an inductor. It adopts small QFN2220-8 package the size of which is 2.2 x 2.0 x 1.5 mm. The RM590 requires only two external capacitors, which removes the necessity of complex wiring and enables designing a compact board with ease. In addition, it also makes radiation noise countermeasures easier, because the RM590 helps reduce radiation noise.

The RM590 series is manufactured at our Yashiro Plant (Kato City, Hyogo), and its inductor is manufactured by one of our group companies. The RM590 is scheduled to be applicable for our Product Longevity Program, maintaining state of supply for 10 years, which leads to relieve customer’s concern on the end of life of products including the inductor.

The input voltage range is from 2.3 V to 5.5 V with a maximum rating of 6.5 V. The RM590 series has two output voltage types: one is the fixed type, an internally fixed output voltage, and the other is the adjustable type, an output voltage variable with external resistors.

The output current is maximum 400 mA. To achieve high conversion efficiency even at light load, the RM590 can automatically switch its operation mode between VFM (Variable Frequency Modulation) and PWM (Pulse Width Modulation) depending on the load current. This function enables the IC to operate with high efficiency at both heavy and light load.

Key Features of RM590 Series

1. DC/DC Switching Regulator IC and Inductor Organized in One Module

The RM590 series is a product which included a synchronous buck DC/DC switching regulator with oscillator frequency of 6 MHz and an inductor in a module. It adopts small QFN2220-8 package the size of which is 2.2 x 2.0 x 1.5 mm. Furthermore, it requires only two external capacitors, which removes the necessity of complex wiring and enables designing a compact board with ease.

2. Automatic PWM/VFM Switching for High Efficiency at Both Heavy and Light Load

The RM590 series can automatically switch its operation mode between VFM (Variable Frequency Modulation) and PWM (Pulse Width Modulation) according to load current to convert efficiently even at light load. This function enables the IC to operate with high efficiency at both heavy and light load. In addition to its small package, the RM590 series can achieve low quiescent current of as low as 15 µA and high conversion efficiency at the same time.

3. Reducing Radiation Noise by Including Inductor

When using DC/DC switching regulators to electronic systems using electromagnetic waves, you need to take countermeasures on radiation noise generated from the DC/DC switching regulator. The noise from the DC/DC converter is radiated outside through wires. Therefore, the shorter the wires are, the less the noise becomes. As the RM590 series has a DC/DC switching regulator IC and an inductor inside, it can reduce noise thanks to the short length of wiring. In addition, the noise generator is covered with a package which works as a shield, so it can reduce noise substantially compared to a conventional product using an external inductor.

Comparation of Radiation Noise

Conventional products with external inductor (RP509)               RM590

4. Reducing Output Ripple Noise with High Oscillator Frequency of 6 MHz

The RM590 series has an oscillator frequency of 6 MHz to minimize ripples which are output noise. This makes the module even usable as a power source for devices with high noise sensitivity.

More info about the RM590 series: https://www.n-redc.co.jp/en/products/dc-dc-switching-regulator/spec/?product=rm590

Pricing and Availability

Pricing and availability info please visit email: sales.europe@macnica.com.

About Ricoh Electronic Devices Co., Ltd

Ricoh Electronic Devices Co., Ltd is a leading global provider of semiconductor products, offering a comprehensive portfolio of CMOS Power Management and Real Time Clock ICs that enable engineers to design advanced applications for the consumer, industrial and automotive markets. The companies headquarter is based in Japan, as well as development, sales and manufacturing facilities. Regional sales and support offices are located in North America, Europe, and Asia.

Ricoh has an extensive expertise in small package technology and has a focus on developing products providing features such as low-supply current, high-accuracy, high efficiency and high-reliability. https://www.n-redc.co.jp/en/