Timing is everything

Not all frequency control products are created equal. Selecting the right vendor is the first step to specifying the right part for your BOM Buyers faced with a bill of materials featuring frequency control components without a specific manufacturer’s part number need a ‘check list’ to ensure they are making appropriate purchasing decisions.

Firstly and most importantly, their vendor should offer insight into the global frequency control industry. Do they have the technical knowledge required to guide customers through the parameters that can affect the performance and longer term viability of end products? Full technical support should be available, both to engineers in the initial stages of design and later, to resolve any production engineering issues.

A global logistics network is also a necessity, because while design and prototyping may be carried out in the UK, full production could be located in Eastern Europe or Asia. Buffer stock facilities, foreign currency pricing and door to door global shipping methods are also ‘must-haves.’

In essence, it is important to pick a vendor that can offer a total supply chain management solution on all frequency control products required, with consistent quality, reliable service and a globally competitive pricing structure.

Next, buyers need to find as much detail on the parts specification and/or application as they can, since without this, it is difficult to offer a meaningful quote. Being able to understand and offer the basics of a specification can significantly reduce failures in initial designs and early production units.

In order to manufacture a crystal, vendors require some basic minimum data. Nominal frequency is that at which the crystal/resonator should operate in the circuit. It is also important to know the package style required as this defines the physical dimensions of the crystal.

The initial manufacturing tolerance of the crystal frequency is normally measured at ambient temperature and specified at 25degC. Initial tolerance is stated in parts per million. Buyers should also know the expected tolerance of the crystal frequency over the specified temperature range of the device and the operating temperature range over which the device should operate. Finally, load capacitance specifications are required for accurate frequency operation.

For oscillator products, the basic requirements are similar, but also include overall tolerance, input voltage and output waveform. There are many options for output waveforms including standard CMOS/TTL square wave types, sine wave outputs and high frequency waveforms such as LVPECL, LVDS. Oscillators are available in many different configurations including clock oscillators, VCXO, VCTCXO, TCXO and OCXO to name some of the common parts.

The correct selection of vendor is vital to ensure correct part specification. AEL Crystals aims to dispel some of the myths surrounding frequency control products with knowledgeable applications engineers to guide and advise customers on product selection and global logistics support throughout production.