SI5319C-C-GM Silicon Laboratories Inc, SI5319C-C-GM Datasheet - Page 16

• Manufacturer Part Number: SI5319C-C-GM
• Description: IC CLOCK MULT/ATTENUATOR 36QFN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI5319C-C-GM

• Input: *
• Output: *
• Frequency - Max: *
• Voltage - Supply: *
• Operating Temperature: *
• Mounting Type: Surface Mount
• Package / Case: 36-VFQFN Exposed Pad
• Frequency-max: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Si5319
3. Functional Description
The Si5319 is a jitter-attenuating precision clock multiplier for applications requiring sub 1 ps jitter performance.
The Si5319 accepts one clock input ranging from 2 kHz to 710 MHz and generates one clock output ranging from
2 kHz to 945 MHz and select frequencies to 1.4 GHz. The Si5319 can also use its crystal oscillator as a clock
source for frequency synthesis. The device provides virtually any frequency translation combination across this
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operating range. The Si5319 input clock frequency and clock multiplication ratio are programmable through an I
C
or SPI interface. Silicon Laboratories offers a PC-based software utility, DSPLLsim, that can be used to determine
the optimum PLL divider settings for a given input frequency/clock multiplication ratio combination that minimizes
phase noise and power consumption. This utility can be downloaded from http://www.silabs.com/timing.
®
The Si5319 is based on Silicon Laboratories' third generation DSPLL
technology, which provides any-frequency
synthesis and jitter attenuation in a highly integrated PLL solution that eliminates the need for external VCXO and
loop filter components. The Si5319 PLL loop bandwidth is digitally programmable and supports a range from 60 Hz
to 8.4 kHz. The DSPLLsim software utility can be used to calculate valid loop bandwidth settings for a given input
clock frequency/clock multiplication ratio.
The Si5319 monitors the input clock for loss-of-signal and provides a LOS alarm when it detects missing pulses on
the input clock. The device monitors the lock status of the PLL. The lock detect algorithm works by continuously
monitoring the phase of the input clock in relation to the phase of the feedback clock.
The Si5319 provides a VCO freeze capability that allows the device to continue generation of a stable output clock
when the selected input reference is lost. During VCO freeze, the DSPLL latches its VCO settings and uses its XO
as its frequency reference.
The Si5319 has one differential clock output. The electrical format of the clock output is programmable to support
LVPECL, LVDS, CML, or CMOS loads. For system-level debugging, a bypass mode is available which drives the
output clock directly from the input clock, bypassing the internal DSPLL. The device is powered by a single 1.8, 2.5,
or 3.3 V supply.
3.1. External Reference
A low-cost 114.285 MHz 3rd overtone crystal or an external reference oscillator is used as part of a fixed-frequency
oscillator within the DSPLL. This external reference is required for the device to operate. Silicon Laboratories
recommends using a high quality crystal. Specific recommendations may be found in the Family Reference
Manual. An external oscillator as well as other crystal frequencies can also be used as a reference for the device.
In VCO Freeze, the DSPLL remains locked to this external reference. Any changes in the frequency of this
reference when the DSPLL is in VCO freeze will be tracked by the output of the device. Note that crystals can have
temperature sensitivities.
3.2. Further Documentation
Consult the Silicon Laboratories Any-Frequency Precision Clock Family Reference Manual (FRM) for detailed
information about the Si5319. Additional design support is available from Silicon Laboratories through your
distributor.
Silicon Laboratories has developed a PC-based software utility called DSPLLsim to simplify device configuration,
including frequency planning and loop bandwidth selection. The FRM and this utility can be downloaded from
http://www.silabs.com/timing.
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