cy25561 Cypress Semiconductor Corporation., cy25561 Datasheet - Page 4

• Manufacturer Part Number: cy25561
• Description: Spread Spectrum Clock Generator
• Manufacturer: Cypress Semiconductor Corporation.

Document #: 38-07242 Rev. *B
Modulation Rate
Spectrum Spread Clock Generators utilize frequency
modulation (FM) to distribute energy over a specific band of
frequencies. The maximum frequency of the clock (Fmax) and
minimum frequency of the clock (Fmin) determine this band of
frequencies. The time required to transition from Fmin to Fmax
and back to Fmin is the period of the Modulation Rate, Tmod.
Modulation Rates of SSCG clocks are most commonly
referred to in terms of frequency or Fmod = 1/Tmod.
Analyzer
Device
CY25561
Example:
Then;
Device =
Fin
Range =
Modulation Rate = Fmod = 65 MHz/2332 = 27.9 kHz.
=
Modulation Profile
Figure 2. SSCG Clock, CY25561, Fin = 65 MHz
Cdiv
2332
CY25561
65 MHz
S1 = 1, S0 = 0
(All Ranges)
The input clock frequency, Fin, and the internal divider count,
Cdiv, determine the Modulation Rate. In some SSCG clock
generators, the selected range determines the internal divider
count. In other SSCG clocks, the internal divider count is fixed
over the operating range of the part. The CY25561 has a fixed
divider count, as listed below.
Spectrum
CY25561
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