P2010A ALSC [Alliance Semiconductor Corporation], P2010A Datasheet - Page 3

• Manufacturer Part Number: P2010A
• Description: Low Frequency EMI Reduction IC
• Manufacturer: ALSC [Alliance Semiconductor Corporation]

P2010A
November 2003
rev F
Spread Spectrum Selection
Table 1 illustrates the possible spread spectrum options. The optimal setting should minimize system EMI to the
fullest without affecting system performance. The spreading is described as a percentage deviation of the
center frequency (Note: the center frequency is the frequency of the external reference input on CLKIN, Pin 1).
Example of a typical printer or scanner application that operates on a clock frequency of 16 MHz:
A spreading selection of FS0=1 and SR0=1 provides a percentage deviation of +/-2.50%* (see Table 1) of F
.
cen
This results in the frequency on ModOUT being swept from 16.40 MHz to 15.60 MHz at a modulation rate of
33.33 KHz (see Table 1). This particular example (see Figure below) given here is a common EMI reduction
method for scanner, printer, or embedded applications and has already been adopted by most of the leading
manufacturers.
NOTE: Spreading range selection varies from different system manufacturers and their designs.
P2010 Application Schematic for Flat-Bed Scanner
Low Frequency EMI Reduction IC
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Notice: The information in this document is subject to change without notice.