30V, 2A PWM DC/DC Converter with EMI Noise Reduction

30V, 2A PWM DC/DC Converter with EMI Noise Reduction

Ricoh Europe (Netherlands) B.V. Semiconductor Support Centre has launched the R1275, a high-efficiency, 2A synchronous step-down DC/DC converter with a wide input voltage range up to 30V and has two options to minimize electromagnetic interference (EMI). It allows connecting to a variety of input sources, such as battery-powered portable devices, industrial supplies and automotive batteries.

There are many ways to reduce radiated and conducted EMI significantly, but few are as simple as using a Spread Spectrum Clock Generator (SSCG). The idea behind using SSCG is to modulate the clock frequency mildly, which results in spreading the EMI energy amongst many frequencies instead of concentrated at one frequency. This way, the amount of potential interference of the base frequency and its harmonics is reduced considerably.

The switching frequency is internally set to 2MHz, but it is also possible to synchronize with another DC/DC Converter by applying an external clock signal from 1.8MHz to 2.2MHz. Especially in case the power supply consists of multiple DC/DC converters, the individual switching frequencies can result in a significant noise in common ground wiring. By synchronizing all DC/DC converters to one frequency, the resulting noise is easier to filter out and will not interfere with the control of the converters.

More information: Ricoh