Introduction of the five elements that affect the quotation of single chip microcomputer crystal oscillator

Crystal oscillator quotation also gradually fell, many electronic components to buy personnel are very question, why the demand to buy crystal frequency is the same, but the price is so different?The following shenzhen juntelli on briefly under the impact of the impact of the MCU crystal oscillator quotation of the five elements.

1. Crystal frequency: is the nominal frequency of crystals, usually can have marked on the surface of the crystal shell, it is marked with the words of the most neutral laser printing, such as: 11.0592 MHZ and 12.000 MHZ and 24.576 MHZ and 18.432 MHZ, sometimes the manufacturer may also be marked on the code directly is not the word, like a cylindrical column crystal 32.768 KHZ sometimes no label word in order to cut costs, needs look at the outer packing have no similar words at this moment, maybe have the condition with crystals a brief test instrument test.Other, quotation also is not to say frequency is higher more expensive, want to generalize look.Of course, some offset frequency point crystal vibration quotation will also be relatively high, scarce for the expensive.

2. Crystal oscillator type: the active crystal oscillator is an intact oscillator, which is composed of quartz crystal, resistor-capacitance element and transistor element.The passive crystal oscillator depends on the clock circuit or the crystal itself can not oscillator up, in a nutshell is the active crystal oscillator with voltage, the passive crystal oscillator without voltage.Active crystal oscillators are more expensive than passive crystal oscillators because of their different internal structures.

3. Load capacitance: load capacitance refers to all the useful capacitors in the direction of the sensational circuit in both pins of the crystal oscillator.Usually, the load capacitors of MHZ frequency points are 12PF, 16PF, 20PF, 33PF, etc., and the load capacitors of 32.768khz frequency points are 6PF, 9PF, 12.5pf, etc. The load capacitors of crystal oscillator with the same frequency are not necessarily the same. The more frequently used load capacitors with the same frequency on the quotation are cheaper.

4. Crystal oscillator packaging: active crystal oscillator packages include dip-14 dip-8 and SMD patch models of 2025, 3225, 4025, 5032 and 7050.The package of passive crystal is directly inserted with hc-49s hc-49u cylinder 3*8 2*6mm, and patch type with hc-49smd 6035, 3225, 2025, 5032, 7050, 7045, etc.

5. Crystal vibration precision: the crystal vibration precision unit is PPM, refers to the crystal work temperature planning within the fault, the more common precision planning has 10ppm, 20ppm, 30ppm, 50ppm, 100ppm, beyond the 100ppm crystal will have some work is not normal, this can be said that the higher the accuracy of the quotation is higher.