EVL6563S-400W STMicroelectronics, EVL6563S-400W Datasheet - Page 28

• Manufacturer Part Number: EVL6563S-400W
• Description: EVAL BOARD FOR L6563(400W)
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of EVL6563S-400W

• Main Purpose: Power Management, Power Factor Correction
• Embedded: No
• Utilized Ic / Part: L6563
• Primary Attributes: 400W Power Factor Correction and Preregulator Combination
• Secondary Attributes: Transition Mode & Active Tracking Boost Function.
• Maximum Operating Temperature: + 60 C
• Product: Power Management Development Tools
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: L6563S
• Other names: 497-10488

Audible noise
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Audible noise
Differential mode currents in a circuit with high- and low-frequency components (like in a
PFC) may produce audible noise due to inter-modulation between the operating frequency
and the mains line frequency.
This phenomenon occurs because of the mechanical vibration of reactive components like
capacitors and inductors. Current flowing in the winding can cause the vibration of wires or
ferrite, and as such produce buzzing noise. To avoid this, the boost and filter inductors have
to be wound with a correct wire tension and the component has to be varnished or dipped.
Frequently, X-capacitors and filter capacitors after the bridge generate acoustic noise
because of AC current that causes the electrodes to vibrate, producing buzzing noise. Thus,
minimizing the AC current by inserting a differential-mode, Pi filter between the bridge and
the boost inductor helps to reduce the acoustic noise. The EMI filter will also benefit from
this. In fact, such a filter significantly decreases the ripple current that otherwise has to be
filtered by the EMI filter. The capacitors to be selected are of a polypropylene (preferably
dipped) type because boxed ones are generally more at risk of generating acoustic noise.
Doc ID 15796 Rev 2
AN2994