Ricoh launches new RP509 0.5A / 1A PWM/VFM Step-down DC/DC Converter with Synchronous Rectifier
Amstelveen, the Netherlands, 31 July 2015– Ricoh Europe (Netherlands) B.V. Semiconductor Support Centre has launched a new PWM/VFM Step-down DC/DC Converter RP509 with Synchronous Rectifier and an optional output current limit of 0.5A or 1A. The new product offers a small footprint on the circuit board and requires small external components due to its high operating frequency of 6MHz.
The RP509 is one of the world’s most compact Step-down DC/DC Converter solutions with a package occupying only 1.12mm2 of circuit board space. This contributes to the product efficiency when used on high density and small circuit boards in portable gadget applications, such as smartphones, smart/fitness watches, tablets, wearable devices and communication modules. Other factors contributing to circuit board space reduction are the high operating frequency of 6.0MHz (resulting in the use of a small sized inductor of 0.47µH), an embedded driver transistor and synchronous rectification, which eliminates the need of an external diode.
The RP509 has two operating modes, selected by a mode pin:
- Forced PWM operating mode; the DC/DC converter switches at a fixed frequency rate, which has a lower output noise versus VFM operating mode.
- PWM/VFM auto switching mode; the DC/DC Converter switches between PWM and VFM mode automatically, resulting in the best efficiency level at either low or high output current demand.
Step-down DC/DC Converters need to function in a similar way to LDOs, providing power to advanced processors resulting in a load with fast transients. Portable gadget applications are able to operate in versatile modes, each with specific load characteristics.
In terms of circuit protection, various circuits are embedded to ensure a safe operation of the power supply. An under voltage lockout function (UVLO) disables the RP509 if the input voltage is below the threshold of the minimum operating voltage. An over-current limit circuit restricts the Lx peak current at each clock cycle; if the current exceeds the current limit it turns off the P-channel transistor. The over-current limit protects the DC/DC Converter and other electronic parts of the application from damage. One can select between versions with 0.5A or 1.0A current limit. The internal thermal shutdown circuit disables the RP509 as soon the junction temperature reaches 140°C and releases the protection circuit at 100°C.
The embedded soft-start function boots the internal circuits in 150µs. The output voltage version is fixed internally, which can be set in a range from 0.6V to 3.3V; the adjustable output voltage can be set from 0.6V to 5.5V with an external voltage divider. An optional auto-discharge function discharges the output capacitor quickly when the RP509 is disabled by the CE pin; an embedded transistor connected at the Vout pin is turned on and shorts the capacitor to ground.
Ricoh is a global technology company specializing in office imaging equipment, production print solutions, document management systems and IT services. Headquartered in Tokyo, Ricoh Group operates in about 200 countries and regions. In the financial year ending March 2014, Ricoh Group had worldwide sales of 2,236 billion yen (approx. 21.7 billion USD).
The majority of the company's revenue comes from products, solutions and services that improve the interaction between people and information. Ricoh also produces award-winning digital cameras and specialized industrial products. It is known for the quality of its technology, the exceptional standard of its customer service and sustainability initiatives.
Under its corporate tagline, imagine, change, Ricoh helps companies transform the way they work and harness the collective imagination of their employees.
In March 2001 Ricoh Europe (Netherlands) B.V. established the Semiconductor Support Centre to represent the services of Ricoh Electronics Devices Company Japan in Europe. The Semiconductor Support Centre supports European distributors and electronics designers and manufacturers with their applications or other enquiries for Power Management and Real Time Clock ICs.
In July 2013 Ricoh Electronics Devices Company became ISO / TS16949:2009 certified; it is an important additional improvement of our quality management system for the design, development and manufacturing of semiconductor products for the automotive market.
For further information, please visit our Semiconductor product website www.ricoh.com/LSI