SI5351 High Frequency square wave Signal Generator Module

SI5351 High Frequency Square Wave Signal Generator Module is a versatile clock generator that uses the innovative Silicon Labs Si5351A IC to produce up to three independent, non-integer related clock frequencies from a single crystal reference. This module effectively replaces multiple crystals and oscillators, consequently simplifying circuit design and reducing overall component count in frequency synthesis applications. It generates highly accurate square wave signals ranging from 8 kHz up to 160 MHz, making it an ideal choice for radio, embedded, and test equipment designs. Furthermore, you can easily configure the Si5351 via the I²C interface, allowing microcontrollers to dynamically change output frequencies on the fly for phase-locked loop (PLL) and clock distribution tasks. Therefore, engineers use this module to achieve flexible and precise timing solutions in complex digital systems.

Key Features:

• Wide Frequency Range: Generates square wave output signals from 8 kHz up to 160 MHz across three independent channels.
• High Precision: Utilizes an internal PLL (Phase-Locked Loop) and VCO (Voltage Controlled Oscillator) combined with a crystal reference for high-accuracy and low-jitter frequency synthesis.
• Three Independent Outputs: Provides three separate clock outputs (CLK0, CLK1, CLK2), each capable of generating a unique, customizable frequency.
• I²C Control: Features a simple two-wire I²C interface, enabling effortless integration and runtime frequency programming by a host microcontroller.
• Single Crystal Reference: Requires only one external crystal oscillator (typically 25 MHz or 27 MHz) to generate all three output frequencies, saving space and cost.

Technical Specifications:

• Clock Generator IC: Silicon Labs Si5351A
• Output Channels: 3 (CLK0, CLK1, CLK2)
• Output Frequency Range: 8 kHz to 160 MHz (Square Wave)
• Reference Crystal: Typically 25 MHz or 27 MHz (Onboard)
• Control Interface: I²C (Up to 400 kHz)
• Supply Voltage (V_CC): 3.3 V to 5 V DC
• Output Jitter: Typically ≤ 100 ps RMS

Mechanical Specifications:

• Package Type: Small PCB module with header pins.
• Mounting: Pin headers suitable for breadboard or through-hole PCB integration.
• Output Impedance: 50 Ω nominal on clock outputs.

Dimensions:

• Module Length: ≈ 20 mm
• Module Width: ≈ 15 mm
• Pin Pitch: 2.54 mm (0.1 inch)
• Weight: ≈ 2 g (Ultra-lightweight)

Pinout and Wiring:

• VCC: Connect to 3.3 V or 5 V power supply.
• GND: Connect to the common ground reference.
• SCL: I²C Clock line. Connect to the microcontroller’s I²C SCL pin.
• SDA: I²C Data line. Connect to the microcontroller’s I²C SDA pin.
• CLK0, CLK1, CLK2: Digital clock output pins (Square wave signals).
• Wiring Note: The SCL and SDA lines typically require external pull-up resistors (e.g., 4.7 kΩ) to VCC for proper I²C communication.

Datasheet Reference:

• Download Silicon Labs Si5351A/B/C Clock Generator Datasheet

Commonly Used in:

• Software Defined Radios (SDR): Provides the necessary local oscillator (LO) and clocking signals for receivers and transmitters.
• Test and Measurement Equipment: Used in frequency counters, signal sources, and laboratory calibration tools.
• Amateur Radio (Ham Radio): Core component in VFOs (Variable Frequency Oscillators) and BFOs (Beat Frequency Oscillators).

Applications:

• Frequency Synthesizers: Creating multiple, highly stable clock signals from a single reference for communication equipment.
• Clock Distribution: Providing reliable timing for high-speed ADCs/DACs and digital logic across a circuit board.
• High-Speed Data Acquisition: Serving as the sampling clock for complex digital signal processing (DSP) systems.

Equivalent Models:

• AD9850/AD9851 (Analog Devices): These are DDS (Direct Digital Synthesis) chips that offer high-resolution sine wave generation, however, the Si5351 typically offers a wider frequency range for square wave clocking.
• MAX038 (Maxim Integrated): A function generator IC, but ultimately, the Si5351 provides a much simpler digital interface and multi-output capability.

Package Includes:

• 1 x SI5351 High Frequency Square Wave Signal Generator Module