MLAB
Module
mlab mlab-module clkgen clock clock-generator comm-rf

CLKGEN01

Single output I2C programmable clock generator.

This is an open-source hardware design, one of the modules from the MLAB labolatory system.

CLKGEN01 - Single output I2C programmable low-jitter clock generator

CLKGEN01B

Description

The CLKGEN01B is a low-jitter, single-output, I2C programmable clock generator designed for high-end ADC in SDR applications. It is suitable for generating a stable, low-noise clock signal with a wide tunable frequency range.

Technical Parameters

  • Power Voltage: Max 5V, 160mA
  • Core Power Voltage: +1.8V, 2.7V, 3.3V (depends on chip type)
  • Frequency Range: 10 - 1500 MHz (depends on chip type, usually 10 - 810MHz)
  • Phase Jitter: < 0.3ps for Si570 types

Construction

Circuit

The circuit is optimized for direct connection to a microprocessor with similar or higher output logic levels over the Si5XX chip. A voltage level translator is integrated for applications requiring different voltage levels. The internal lower voltage can be stabilized by the integrated linear voltage stabilizer. The module output is differential, but a single-sided CMOS output chip can be populated.

EMI Suppression

The CLKGEN01B module can be a significant source of noise due to its signal-generator nature. Proper EMI isolation is necessary, which can be achieved using a high conductive base like ALBASE.

Mechanical Construction

The module is mounted on a base using four screws. To ensure proper shielding, it is recommended to secure all screws with a conductive base.

Testing

Setting

On startup, a preset frequency is sent at the output. There is an option to calibrate the clock source via the I2C bus.

Software Tools

In combination with other modules, the generator can be tuned via a computer. One simple solution is using the PIC18F4550v01A module and firmware, allowing the use of any software compatible with the design, such as USBSynth or CFGSR.

Documentation and Downloads

References