™
Ultra Series Crystal Oscillator
Si547 Data Sheet
Ultra Low Jitter Quad Any-Frequency XO (80 fs), 0.2 to 1500
MHz
KEY FEATURES
• Available with any four selectable
frequencies from 200 kHz to 1500 MHz
The Si547 Ultra Series™ oscillator utilizes Silicon Laboratories’ advanced 4th gener-
ation DSPLL® technology to provide an ultra-low jitter, low phase noise clock at four
selectable frequencies. The device is factory-programmed to provide any four se-
lectable frequencies from 0.2 to 1500 MHz with <1 ppb resolution and maintains ex-
ceptionally low jitter for both integer and fractional frequencies across its operating
range. The Si547 offers excellent reliability and frequency stability as well as guar-
anteed aging performance. On-chip power supply filtering provides industry-leading
power supply noise rejection, simplifying the task of generating low jitter clocks in
noisy systems that use switched-mode power supplies. Offered in industry-standard
3.2x5 mm and 5x7 mm footprints, the Si547 has a dramatically simplified supply
chain that enables Silicon Labs to ship custom frequency samples 1-2 weeks after
receipt of order. Unlike a traditional XO, where a different crystal is required for each
output frequency, the Si547 uses one simple crystal and a DSPLL IC-based ap-
proach to provide the desired output frequencies. This process also guarantees
100% electrical testing of every device. The Si547 is factory-configurable for a wide
variety of user specifications, including frequency, output format, and OE pin loca-
tion/polarity. Specific configurations are factory-programmed at time of shipment,
eliminating the long lead times associated with custom oscillators.
• Ultra low jitter: 80 fs Typ RMS
(12 kHz – 20 MHz)
• Excellent PSRR and supply noise
immunity: –80 dBc Typ
• 7 ppm stability option (-40 to 85C)
• 3.3 V, 2.5 V and 1.8 V V supply
DD
operation from the same part number
• LVPECL, LVDS, CML, HCSL, CMOS, and
Dual CMOS output options
• 3.2×5, 5x7 mm package footprints
• Samples available with 1-2 week lead times
APPLICATIONS
• 100G/200G/400G OTN, coherent optics
• 10G/25G/40G/100G Ethernet
Pin Assignments
• 3G-SDI/12G-SDI/24G-SDI broadcast video
FS1
• Servers, switches, storage, NICs, search
acceleration
7
1
2
3
6
5
4
VDD
CLK-
CLK+
OE/NC
NC/OE
GND
• Test and measurement
• Clock and data recovery
• FPGA/ASIC clocking
8
FS0
(Top View)
Pin #
Descriptions
Selectable via ordering option
Fixed
Frequency
Crystal
Frequency
Flexible
DSPLL
1, 2
Low
Noise
Driver
OE = Output enable; NC = No Connect
DCO
Digital
Phase
Detector
Digital
Loop
Filter
3
4
5
6
7
8
GND = Ground
OSC
Phase Error
Cancellation
Flexible
Formats,
1.8V – 3.3V
Operation
CLK+ = Clock output
Phase Error
Fractional
Divider
CLK- = Complementary clock output. Not used for CMOS.
VDD = Power supply
NVM
Control
Power Supply Regulation
FS1 = Frequency Select 1
OE, Frequency Select
(Pin Control)
Built-in Power Supply
Noise Rejection
FS0 = Frequency Select 0
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