Ultra Series
™
Crystal Oscillator
Si545 Data Sheet
Ultra Low Jitter Any-Frequency XO (80 fs), 0.2 to 1500 MHz
The Si545 Ultra Series
™
oscillator utilizes Skyworks Solutions’ advanced 4
th
genera-
tion DSPLL
®
technology to provide an ultra-low jitter, low phase noise clock at any
output frequency. The device is factory-programmed to any frequency from 0.2 to
1500 MHz with <1 ppb resolution and maintains exceptionally low jitter for both inte-
ger and fractional frequencies across its operating range. The Si545 offers excellent
reliability and frequency stability as well as guaranteed aging performance. On-chip
power supply filtering provides industry-leading power supply noise rejection, simplify-
ing the task of generating low jitter clocks in noisy systems that use switched-mode
power supplies. Offered in industry-standard footprints, the Si545 has a dramatically
simplified supply chain that enables Skyworks 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 Si545 uses one simple crystal and a DSPLL
IC-based approach to provide the desired output frequency. This process also guar-
antees 100% electrical testing of every device. The Si545 is factory-configurable for
a wide variety of user specifications, including frequency, output format, and OE pin
location/polarity. Specific configurations are factory-programmed at time of shipment,
eliminating the long lead times associated with custom oscillators.
KEY FEATURES
• Available with any frequency from 0.2
MHz to 1500 MHz
• Ultra low jitter: 80 fs Typ RMS
(12 kHz – 20 MHz)
• Excellent PSNR and supply noise
immunity: –80 dBc Typ
• 7 ppm stability option (–40 to 85 °C)
• 3.3 V, 2.5 V and 1.8 V V
DD
supply
operation from the same part number
• LVPECL, LVDS, CML, HCSL, CMOS, and
Dual CMOS output options
• 2.5×3.2, 3.2×5, 5×7 mm package options
• Samples available with 1-2 week lead
times
APPLICATIONS
• 100G/200G/400G OTN, coherent optics
• 10G/40G/100G optical ethernet
• 3G-SDI/12G-SDI/24G-SDI broadcast
video
• Datacenter
• Test and measurement
• Clock and data recovery
• FPGA/ASIC clocking
Pin Assignments
1
2
3
6
5
4
GND
NC/OE
VDD
CLK+
CLK-
OE/NC
(Top View)
Pin # Descriptions
1, 2 Selectable via ordering option
OE = Output enable; NC = No connect
3 GND = Ground
4 CLK+ = Clock output
5 CLK- = Complementary clock output. Not used for CMOS.
6 VDD = Power supply
Phase Error
Cancellation
Fixed
Frequency
Crystal
Frequency
Flexible
DSPLL
Low
Noise
Driver
Digital
Loop
Filter
DCO
Digital
Phase
Detector
Fractional
Divider
Phase Error
OSC
Power Supply Regulation
NVM
Built-in Power Supply
Noise Rejection
Control
Output Enable
(Pin Control)
Flexible
Formats,
1.8V – 3.3V
Operation
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
1 Rev. 1.3 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • December 3, 2021 1
