New Industry Products

Renesas Debuts a Series of 700V Non-Isolated Buck Converters

July 08, 2021 by Gary Elinoff

The units operate from 85 to 265VAC inputs with outputs at either 2.5, 5 or 8 watts and offer user-selectable output voltages

The RAA2230XX series of three buck regulators all feature an internal 700 volt MOSFET. They can provide outputs as low as 3.3 volts, eliminating the need for a second-stage LDO. Idling current is less than 10mW. Additionally, these devices can also support secondary-side-feedback isolated flyback topology. 

The RAA2230XX Series. Image courtesy of Renesas

When operating close to their rated power, the units operate under constant off-time control, which serves to keep the switching speed above the range of human hearing. During light loads, converters employ the pulse frequency modulation (PFM) mode for better efficiency. The three buck regulators employ frequency dithering to reduce EMI.


The Three Converters

The table below shows the maximum current outputs available at various line input voltages when each of the three units are adjusted for 3.3, 5, 12, or 24 volts. 


The RAA223011 and the RAA223012

The RAA223011 and the RAA223012 offer 5 and 2.5-watt outputs, respectively. Both units feature quiescent currents of less than 100μA, and standby power less than 10mW. These devices both feature typical RDS(ON)s of 14.5Ω.


Timing for the RAA223011 (typical values)

  • Minimum Off-Time: 32μs
  • Maximum On-Time: 17μs
  • Minimum Off-Time in Short-Circuit: 200μs
  • Hiccup Restart Delay: 100ms


Timing for the RAA223012 (typical values)

  • Minimum Off-Time: 19μs
  • Maximum On-Time: 15μs
  • Minimum Off-Time in Short-Circuit: 200 μs
  • Hiccup Restart Delay: 100ms

Typical application circuit. Image courtesy of RAA22302 datasheet

For the higher power RAA223021, Renesas suggests a bridge rectifier input.



The RAA223021 features a standby power of less than 20mW, with a quiescent current spec'd at less than 80µA. The typical RDS(ON) of the internal MOSFET is as low as 4Ω

Timing (typical values):

  • Minimum Off-Time: 23μs
  • Maximum On-Time: 14 μs
  • Minimum Off-Time in Short-Circuit: 150 μs
  • Hiccup Restart Delay: 90ms


Protection Features Include: 

  • Short-Circuit Protection (SCP)
  • Overload Protection (OLP)
  • Over-Temperature Protection (OTP)
  • Open Feedback



  • Industrial controls
  • White goods
  • Small appliances
  • Bias power
  • Metering
  • Smart home
  • Alarms
  • IoT


Physical Considerations

  • Recommended ambient temperature operating range is from  -40 +85°C
  • The RAA223012 is available in 5-lead TSOT23 and 8-lead SOIC packages.
  • The RAA223011 is available in 5-lead TSOT23, 7-lead SOIC, and 8-lead SOIC packages
  • The RAA223021 is available in 7-lead SOIC packages


Getting to Market Faster

Renesas offers evaluation boards for this series of buck converters, including: