Input and Output Noise in Buck Converters Explained

Focus:

The various sources of noise on the input and output of a buck converter are analyzed and equations are given for calculating the peak-to-peak values of noise contributed by each noise source. These equations are intended to help designers pick components such as capacitors and MOSFETs that minimize noise generation, and not a way of calculating precise levels of input and output noise. First, the analysis assumes continuous conduction above 0 A in the inductor, a constant dc load, and 100% converter efficiency. Regarding these three conditions, the constant dc load is acknowledged to be an unlikely condition in real applications. In addition, the equations offer a way of calculating noise due to finite capacitance and a capacitor's ESR. However, because these noise sources are not in phase, they cannot be added together directly.

What you’ll learn:

• How to minimize input noise and output noise in buck converter designs

Notes:

Maxim Integrated Products Application Note 986

View the Source

Author & Publication:

no author specified, Maxim Integrated Products, Vendor website, Jul 17 2002

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