Si5351A Clock Generator Breakout Board - 8KHz to 160MHz

Breakout for the Si5351A clock generator IC with onboard 25MHz crystal reference; internal PLL and dividers produce frequencies from <8KHz to 150+MHz over I2C. Useful for generating arbitrary clock signals without stocking individual crystals.

VIN
Board power input. Adafruit Learn states the onboard regulator accepts 3-5VDC and converts it down for the 3V Si5351A chip.
Type · powerVoltage · 3-5VDC input, source-backed by Adafruit Learn pinouts
GND
Common ground for power and logic.
Type · groundVoltage · 0V
SCL
I2C clock line. Adafruit states this pin is level shifted and has a 10K pullup.
Type · i2cVoltage · 3-5V logic
SDA
I2C data line. Adafruit states this pin is level shifted and has a 10K pullup.
Type · i2cVoltage · 3-5V logic
0
Independent generated clock output. Adafruit states the clock outputs are square waves from 0-3V and are also brought out to optional SMA edge-launch connectors.
Type · clock outputVoltage · 0-3V square wave output

RTC & timing

26 other options

DS3231/DS3232 temperature-compensated RTCs, the budget PCF8523 and DS1307, the Si5351A clock generator (8kHz–160MHz), and bare 16MHz crystals — matched to drift tolerance and supply voltage.

View all 26

RTC Module - Super Capacitor visual preview

Related groups

4 groups

LED pixels

WS2812/SK6812 NeoPixel strips, rings and Jewels, APA102 DotStar pixels, and plain analog RGB strips — each matched to its protocol and host, not just its connector.

Components · Addressable LEDs · 176 parts

Bare ICs

74HC logic gates, MCP3008/MCP23017 ADCs and expanders, 24LC256 EEPROM, 4N25-series optocouplers and ULN2803A drivers — bare DIP chips with no breakout-board conveniences like pull-ups or level shifting.

Components · Integrated circuits · 68 parts

Converters

ADS1115/MCP3421 ADCs, MCP4725 and GP8413 DACs, CP2102 USB-UART boards, and I2C plumbing like the LTC4316 address shifter — matched to bus, resolution and signal range.

Components · Interface converters · 115 parts

Memory

24LC32/25LC256 EEPROM, I2C FRAM, 64Mbit PSRAM, and microSD breakouts up to 64GB — matched to write frequency and data volume, not just interface.

Components · Memory & storage · 39 parts

Pin	Type	Function	Voltage
VIN	power	Board power input. Adafruit Learn states the onboard regulator accepts 3-5VDC and converts it down for the 3V Si5351A chip.	3-5VDC input, source-backed by Adafruit Learn pinouts
GND	ground	Common ground for power and logic.	0V
SCL	i2c	I2C clock line. Adafruit states this pin is level shifted and has a 10K pullup.	3-5V logic
SDA	i2c	I2C data line. Adafruit states this pin is level shifted and has a 10K pullup.	3-5V logic
0	clock output	Independent generated clock output. Adafruit states the clock outputs are square waves from 0-3V and are also brought out to optional SMA edge-launch connectors.	0-3V square wave output
1	clock output	Independent generated clock output. Adafruit states the clock outputs are square waves from 0-3V and are also brought out to optional SMA edge-launch connectors.	0-3V square wave output
2	clock output	Independent generated clock output. Adafruit states the clock outputs are square waves from 0-3V and are also brought out to optional SMA edge-launch connectors.	0-3V square wave output

Pinout

LED pixels

Bare ICs

Converters

Memory