Fast and precise testing of standard oscillators and VCXOs as well as TCXO/VCTCXOs

09-11-2021 | IQD | Design & Manufacture

The wish to test oscillators quickly and easily is more than obtainable using the IOSC EVBoard from IQD, part of the Würth Elektronik eiSos Group. This evaluation board is ideal for measuring most surface mount standard oscillators, VCXOs or TCXO/VCTCXOs.

The board is provided with six smaller boards that may be snapped off the mainboard and onto which different sized four-pad oscillators can be soldered. The smaller board can then be soldered to the mainboard. The six different package sizes are 1.6mm x 1.2mm, 2mm x 1.6mm, 2.5mm x 2mm, 3.2mm x 2.5mm, 5mm x 3.2mm and 7mm x 5mm.

As noise in the supply voltage can affect the frequency of the oscillator, the board includes a regulated and filtered supply voltage. It can be freely selected between 1.8V and 5V. This enables the performance of the oscillator to be considered under ideal conditions. However, it could also be required to intentionally include noise through testing to observe the consequences. For this purpose, the device also provides the option to directly connect a supply voltage.

The Enable/Disable function can be tested by manual switching to witness the effect on current draw. Also, there is the opportunity to set this input to 'high' or 'low' through a digital source to measure the enable time. For products with voltage control input such as VCXOs and VCTCXOs, the board incorporates a potentiometer to bring the frequency tolerance and the result of soldering back to the nominal frequency by pulling. This process can further be employed to manually alter the control voltage to simulate the effect on frequency. For sensitive products such as VCTCXOs, as well as to pull the frequency, there is the chance to replace the applied potentiometer resistor by a fixed resistor. This leads to better stability and optimised jitter as well as phase noise. Of course, the pull input can also be fed through an external analog source.

For the output signal, the board provides three configurations. Here the user can select between a CMOS output, a clipped sine or a direct output without buffer or load. All outputs are terminated in an SMA connector.

The evaluation board is offered in two options - as an unpopulated PCB supplied with the appropriate BOM and as a populated board for immediate use. The unpopulated version is currently available free of charge from the company with the next 200 oscillator sample orders.

By Natasha Shek