Tokyo, February 23, 2009 —— Renesas Technology Corp. today announced the R2A20114 Series of power factor correction *1 control ICs (PFC control ICs) employing continuous conduction mode *2 interleaving *3 to enable implementation of compact, highly efficient, low-noise power supply units for high-power products such as computer servers and air conditioners. Sample shipments of the R2A20114 and R2A20104 will begin in April 2009 in Japan.
A PFC control IC is a device in the power supply unit of a product, such as a computer server or digital home appliance, that reduces the generation of unnecessary power and harmonics *4 caused by differences between the input voltage and current waveforms during AC (alternating current) to DC (direct current) conversion. It accomplishes this by shaping the input current waveform to match the input voltage waveform. In recent years, the use of PFC control ICs in power supply units has become widespread in order to improve energy efficiency and ensure compliance with international regulations covering harmonics.
The R2A20114 Series employs the following three functions, including interleaving, to enable implementation of power supply units that are more efficient and generate less noise:
| (1) |
Reduction of ripple current up to one-fourth of former Renesas products through interleaving |
| The R2A20114 Series is the first continuous conduction mode PFC control IC from Renesas employing interleaving for higher efficiency. In interleaved operation a pair of two boost circuits operates alternately to shape the input current waveform. It enables a reduction in the input ripple current up to one-fourth of former Renesas products employing a single boost circuit. |
| (2) |
High conversion efficiency in all load areas is achieved through improvement of efficiency under light loads |
| The R2A20114 Series has a function that stops one of the boost circuits when operating under a light load not requiring high output power. This makes possible the previously difficult task of improving efficiency under a light load, and realizes high conversion efficiency to be achieved in almost all load areas. |
| (3) |
Approx. 6 dB less noise than former Renesas products |
| To reduce switching noise, an issue affecting the continuous conduction mode used to handle high power levels, a new function has been added that optimizes the switching frequency. This results in a reduction in noise generation of about 6 dB compared with earlier Renesas products, contributing to a general reduction in power supply line noise. |
In addition to the above, the R2A20114 Series makes it possible to design thinner and more compact power supply units because its high efficiency and low noise allow use of smaller versions of components such as input filters, boost coils, and input and output capacitors.
The R2A20114 Series also integrates a variety of protection circuits, including a protection function for interleaving operation, which improve the reliability of the power supply system and reduce the number of component parts required for greater simplicity.
The R2A20114 is designed for use with products such as air conditioners and uses a shunt resistor specification for current control. The R2A20104 is for applications such as computer servers and uses a current transformer specification for current control. Both are available in LQFP-40 and SOP-20 surface mount packages.