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I have a KXO-V97T 8MHz crystal. It looks like it's an unusual crystal.

The datasheet contains the following pinout:

  • 1 - h or open
  • 2 - GND
  • 3 - OUTPUT
  • 4 - VCC

enter image description here

A crystal with VCC? I am surprised. The resistance between 2 and 4 is about 80МОhm.

I want to connect the crystal with a STM32 3v3, STM32L152.

  • Can you show the connection diagram of a similar crystal and STM32?
  • Can this crystal work with an STM32L152?
  • Can VCC be 3 volts?
  • How can I connect this crystal to an STM2? Crystals have one output, but the chip has two pins for the crystal.
  • How to calculate a capacitor value?
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  • \$\begingroup\$ Which exact part number/code did you purchase? Datasheets are general for a given model series, and the exact part code defines the details. \$\endgroup\$
    – Justme
    Oct 1, 2020 at 11:44
  • \$\begingroup\$ The number is "KXO-V97T 8 MHz", I can not find datasheet for this model. But I pushcased this model as 3.3 v. \$\endgroup\$
    – nick_n_a
    Oct 1, 2020 at 13:10

2 Answers 2

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Please link the datasheet when you ask this kind of specific question on a part. For example, here is a similar part.

As described, it is an oscillator, not a crystal (though probably containing a crystal as well as the active oscillator circuit). As to whether it is guaranteed to work properly with Vcc = 3.0V, how much power it draws and so on, that will be specified in the datasheet.

You can connect it to an MCU like the STM32 as an external oscillator, and only one pin will be required to carry the square-wave clock signal output to the clock input of the MCU. Details on how to set that up will be in the MCU datasheet. Typically the MCU would start up with an internal oscillator and you would enable the external oscillator input via a few lines of code.

You should tie the enable pin high, either directly or through a resistor.

No external parts are required, but a bypass capacitor from Vcc to GND near the package is recommended, and the trace from the oscillator to the MCU should be as short as reasonable. If, for some reason, it has to be extended you might have to add a series resistor (eg. 33 ohms) to control ringing.

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  • \$\begingroup\$ The datasheet is not contains the voltage value( \$\endgroup\$
    – nick_n_a
    Oct 1, 2020 at 9:04
  • 1
    \$\begingroup\$ @nick_n_a: The voltage is in the datasheet. The datasheet you linked to says "input voltage Vcc 5V." So, it won't run on 3V. \$\endgroup\$
    – JRE
    Oct 1, 2020 at 9:15
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    \$\begingroup\$ Okay, somehow the OP's datasheet link got lost in an edit- I can see it if I look at the edit history. 5V +/-10% is the allowable range for Vcc, so is not guaranteed to work on 3V if that is the correct datasheet. It also draws quite a bit of current (60mA typ/80mA max). But I suspect that is not the correct datasheet since it shows the frequency range as 80.1 to 100.0MHz and it is claimed to be 8MHz. That kind of detail actually really matters, as Andy has found a datasheet with nominal 2.6V Vcc specified. \$\endgroup\$ Oct 1, 2020 at 9:38
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    \$\begingroup\$ The manufacturer's data indicates that the V97 series is available with +1.8/2.5/3.0/3.3V nominal Vdd (which does not include the 2.6V on the datasheet... ). What a dog's breakfast. \$\endgroup\$ Oct 1, 2020 at 9:45
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    \$\begingroup\$ You just need a bypass capacitor like 100nF ceramic across Vdd/GND. Any load capacitors required for the crystal are internal. \$\endgroup\$ Oct 1, 2020 at 11:33
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I have quartz KXO-V97T 8MHz. It looks like it's unusual quartz.

It's only unusual if you consider it to be a quartz crystal: -

enter image description here

It's an oscillator module that contains a quartz crystal and an oscillator circuit hence it needs a power supply.

If you look at the picture you will see that it is to be used on a 2.6 volt DC supply +/- 10%.

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  • 2
    \$\begingroup\$ Is 3.3V within the 2.6V +/- 10% spec? You can get 3.3V rated oscillators too, however, this isn't one of those. \$\endgroup\$ Oct 1, 2020 at 9:21
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    \$\begingroup\$ @nick_n_a can you multiply 2.6 volts by 1.1? \$\endgroup\$
    – Andy aka
    Oct 1, 2020 at 9:22
  • \$\begingroup\$ I hope you know what you are doing. \$\endgroup\$
    – Andy aka
    Oct 1, 2020 at 10:15
  • \$\begingroup\$ What does the value of a capacitor have to do with the topic of this question? \$\endgroup\$
    – StarCat
    Oct 1, 2020 at 10:36
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    \$\begingroup\$ @nick_n_a in my experience, if there's no clear-cut data sheet then ditch that part and use something else offered by a recognized supplier to the industry. \$\endgroup\$
    – Andy aka
    Oct 1, 2020 at 12:52

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