2. Functional Description
The Si5341/40 uses next generation MultiSynth™ technology to offer the industry’s most frequency-flexible, high performance clock
generator. The PLL locks to either an external crystal (XA/XB) or to an external input on XAXB, IN0, IN1 or IN2. The input frequency
(crystal or external input) is multiplied by the DSPLL and divided by the MultiSynth™ stage (N divider) and R divider to any frequency
in the range of 100 Hz to 712.5 MHz per output. The phase-locked loop is fully contained and does not require external loop
filter components to operate. Its function is to phase lock to the selected input and provide a common reference to all the output
MultiSynth high-performance fractional dividers (N). The high-resolution fractional MultiSynth™ dividers enables true any-frequency
input to any-frequency on any of the outputs. A crosspoint mux connects any of the MultiSynth divided frequencies to any of the
outputs drivers. Additional output integer dividers (R) provide further frequency division if required. The frequency configuration of
the device is programmed by setting the input dividers (P), the DSPLL feedback fractional divider (M_NUM/M_DEN), the MultiSynth
fractional dividers (N_NUM/N_DEN), and the output integer dividers (R). Silicon Labs’ Clockbuilder Pro configuration utility determines
the optimum divider values for any desired input and output frequency plan.
The output drivers offer flexible output formats which are independently configurable on each of the outputs. This clock generator is
fully configurable via its serial interface (I
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C/SPI) and includes in-circuit programmable non-volatile memory. The block diagram for the
Si5341 is shown in
Figure 2.1 Si5341 Detailed Block Diagram on page 10
, and the block diagram for the Si5340 is shown in
2.2 Si5340 Detailed Block Diagram on page 11
Si5341, Si5340 Rev D Family Reference Manual • Functional Description
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
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Rev. 1.3 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • July 26, 2021
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