Macnica GmbH

Editorial contact:

Name Stefan Tauschek
Telephone +49 (0)841 88198-0

Ricoh launches two VFM mode Buck DC/DC Converters with 300 nA quiescent current for IoT devices and wearables

Amstelveen, the Netherlands, 29 January 2018 – Ricoh Electronic Devices Co., Ltd. in Japan has launched two VFM mode Buck DC/DC Converters RP511 and RP512, designed to use in wearable devices and applications for Internet of Things (IoT) requiring low current consumption to extend battery life. Additionally, the products also feature a minimum of external components and are available in a small package to reduce circuit board space.PR23_Ricoh_RP511_RP512_2017_18oLogos.png

Today’s wearable and IoT devices mainly operate in a sleep mode and therefore power consumption is significantly defined by the quiescent current which refers to a circuit’s quiet state, not driving any load. In this mode, the system is idle but ready to wake up at any time to perform a task, transmitting some data and resume to sleep mode again.

The RP511 and RP512 have an impressive low quiescent current and consume only 300 nA, prolonging battery life or makes it possible for the designer to select a smaller sized battery for the application. The difference between the two products is their output current capability, they can provide respectively 100 and 300 mA. Both products offer synchronous rectification and have high and low side MOSFET driver transistors embedded, eliminating the need for an external diode in the circuit. As for the available packages, one can select from a SOT-89-5, DFN2527-10 and the smallest solution is provided by the product in a WLCSP-8-P1 package. With three external components it occupies in total only 8.0 or 10.6 mm2 of circuit board area.

The DC/DC Converters operate in a VFM mode which is best to achieve a high efficiency performance at low output current demands, the peak efficiency is around 95%.

A number of protection circuits are integrated, such as an Under Voltage Lock-Out circuit disabling the DC/DC Converter in case the input voltage drops below a minimum threshold. A soft-start circuit controls the output voltage to ramp-up smoothly and prevents any output overshoot and undershoot during the start-up period. The Lx current limit circuit prevents the peak current through the inductor to exceed a specific maximum current threshold.

The RP511 and RP512 have an optional auto-discharge function, this feature rapidly discharges the output capacitor once the chip is disabled by the CE pin.

Features RP511 / RP512

Input Voltage Range 2.0 V to 5.5 V
Output Voltage Range (in 0.1 V step) 1.0 V to 4.0 V
Output Voltage Accuracy (Vset ≥ 1.2 V) ±1.5%, (Vset < 1.2 V) ±18 mV
Output Current 100 mA / 300 mA
Quiescent Current (device not switching) Typ. 300 nA
Standby Current 0.01 µA
PMOS On-Resistance (Vin = 3.6V, RP511Z / RP512Z) 0.15 Ω
NMOS On-Resistance (Vin = 3.6V, RP511Z / RP512Z) 0.15 Ω
Protection Circuits UVLO, Soft-Start, Lx Current Limit
Peak Efficiency (Vin = 2.0 V, Vout = 1.8 V) 95%
Operating Frequency Up to 1 MHz
Auto-Discharge Function Optional
Package WLCSP-8-P1, DFN2527-10, SOT89-5


Pricing and Availability
For information about Pricing and availability info via email:

About Ricoh
Ricoh is empowering digital workplaces using innovative technologies and services enabling individuals to work smarter. For more than 80 years, Ricoh has been driving innovation and is a leading provider of document management solutions, IT services, commercial and industrial printing, digital cameras, and industrial systems.

Headquartered in Tokyo, Ricoh Group operates in approximately 200 countries and regions. In the financial year ended March 2017, Ricoh Group had worldwide sales of 2,028 billion yen (approx. 18.2 billion USD). For further information, please visit

In March 2001 Ricoh Europe (Netherlands) B.V. established the Semiconductor Support Centre to support European distributors and electronics designers and manufacturers with their applications or other enquiries about Power Management and Real Time Clock ICs. For further information, please visit