Adafruit Si5351A Clock Generator Breakout

The Adafruit Si5351A clock generator module removes the need to hunt for new crystals — it includes a precise 25 MHz reference crystal, internal PLLs and dividers that can generate virtually any frequency from 8 kHz to 160 MHz.

The Si5351A is an I2C-controlled clock generator. The internal reference crystal drives multiple PLLs and dividers to form accurate and freely selectable frequencies. The outputs provide three independent channels, each able to have a different frequency. The output is 3 Vpp, available either from a solder-friendly header or an RF-suitable SMA connector (output #1).

The module is implemented in the STEMMA QT form factor, making it easy to attach to various development platforms. STEMMA QT connectors are compatible with SparkFun Qwiic connectors, enabling solderless connections and chaining of other I2C devices. The onboard 3.3 V LDO regulator and level shifters make the module compatible with both 3 V and 5 V logic.

Adafruit also provides a comprehensive library and guides for Arduino and CircuitPython/Python environments to speed up development. Find these and much more under the Links heading.

Specifications:

• Generates up to 3 independent frequencies from 8 kHz to 160 MHz
• I2C-controlled, user-configurable setup
• Accurate frequency synthesis (0 ppm error)
• Very linear VCXO
• Low output jitter: 100 ps pp
• Programmable rise/fall time
• Glitchless frequency switching
• Low power consumption
• PCIe Gen1 compatible, HCSL swing support
• Uses an inexpensive, fixed-frequency 25 MHz crystal oscillator

Product dimensions:

• Size: 25.3 mm x 17.7 mm x 4.7 mm
• Weight: 1.7 g

Package includes:

• Adafruit Si5351A clock generator
• pin header

Links:

Product information page