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I have a 4-pin crystal oscillator/resonator - pins 2 & 4 are ground - do I simply apply 5V at pin 1 in order to generate a square 16MHz wave at the output pin (4)? I have searched and searched the net for a satisfactory answer but everything seems to be answering more advanced aspects of the circuit.

The actual chip is the X322516MLB4SI, but hopefully - pinouts aside - all 4-pin oscillator chips will work in roughly the same way.

Thanks to the answers below, I now know that the above device is simply a crystal in essence, so now I'll rephrase my question:

I wish to apply a 5V current to some sort of oscillator chip in order to generate a 16MHz clock signal. Any pointers as to what I would need - crystal oscillator chip? resonator chip? etc. This is the ultra-basic first step I cannot find the answer to.

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    \$\begingroup\$ datasheet.lcsc.com/lcsc/… \$\endgroup\$
    – Bruce Abbott
    Commented Jul 31, 2022 at 22:05
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    \$\begingroup\$ Search on crystal oscillator circuit. Find one that uses a CMOS inverter. \$\endgroup\$
    – Mattman944
    Commented Jul 31, 2022 at 22:35
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    \$\begingroup\$ You want a "crystal oscillator module". Unfortunately, web searches for "crystal oscillator" or "crystal oscillator module" bring up lots of references to bare crystals. A search at a distributor like Digikey will allow you to find actual oscillator modules. They will generally have four pins: Power, Ground, Output and (maybe) control/enable. \$\endgroup\$
    – Peter Bennett
    Commented Jul 31, 2022 at 22:45
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    \$\begingroup\$ I have answered the question myself below for the enlightenment of future users. Yes, search engine results are shockingly poor when searching "crystal oscillator module" and such like. And the chip I've found indeed has Power, Ground, Output and optional Control! \$\endgroup\$
    – Hektor
    Commented Jul 31, 2022 at 23:05

3 Answers 3

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It's not a crystal oscillator, it's just a crystal.

So no, it won't oscillate by itself after applying power. You need an oscillator to make a crystal oscillator.

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    \$\begingroup\$ OK so I wish to apply a 5V current to some sort of oscillator chip in order to generate a 16MHz clock signal. Any pointers as to what I would need - crystal oscillator chip? resonator chip? etc. This is the ultra-basic first step I cannot find the answer to. \$\endgroup\$
    – Hektor
    Commented Jul 31, 2022 at 22:18
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Procure a crystal oscillator with CMOS output. They come in similar packages. You will need to apply supply voltage in the specified range and you'll typically want to put a bypass capacitor near the oscillator power pins.

Here is a search at a US-based distributor which should lead to some datasheets.

Note that many of them are not happy with a 5V supply; these days they're expecting more like 1.8 to 3.3V. Also the power consumption of these oscillators tends to be a bit high compared to on-chip MCU oscillators eg. CTS MXO45 can draw as much as 40mA which is enough to run an oscillator and an entire 32-bit ARM chip with FPU and tons of peripherals/memory with mA to spare.

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First, ideally I wanted a 14MHz clock, but thought it would be easier to locate a 16MHz output.

Thanks for all the help so far, I just thought that in terms of identifying an actual chip that will allow the application of 5V to generate a 14MHz clock on the output pin, it is worth posting my own answer:

https://jlcpcb.com/partdetail/361069-S7D14318180A20F30T/C386981

This oscillator chip appears to tick the necessary boxes.

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    \$\begingroup\$ Yup; that is an oscillator. It's at 14.3(18) MHz. If you can live with that, just apply 5V to pin 4, ground to pin 2. Your output will be between pin 3 (and ground, pin 2). Also apply a 100nF capacitor between power (pin 4) and ground (pin 2). \$\endgroup\$
    – M1GEO
    Commented Aug 1, 2022 at 22:31
  • \$\begingroup\$ For some reason I have placed a 10nf cap between power and ground, I think that was advised in the datasheet. Also can I wire the 5V input to the main power rail or should I decouple it with a 100nf and a 10nf parallel decoupler, as with every other chip on the board? \$\endgroup\$
    – Hektor
    Commented Aug 11, 2022 at 14:22
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    \$\begingroup\$ My typical answer would be to do what the datasheet tells you to do. 10nF may be fine. A modern 10nF and 100nF in parallel is probably a bit pointless as you're trying to overcome resonances in the parts but 10nF and 100nF are a bit close together. For more info on decoupling, Dave Jones at EEVBlog has some references: youtube.com/watch?v=BcJ6UdDx1vg \$\endgroup\$
    – M1GEO
    Commented Aug 11, 2022 at 23:09
  • \$\begingroup\$ Thanks for the tips. Epic link, feels great to rediscover Dave Jones now I have a better grasp on the basics. Just as a heads up, what's your suggestion as a better pairing for bypasses on TTL logic - my guess might be 3nf and 100nf? Also, on a related note, how useful are bypasses on ground pins for 5V systems? Overkill, or just ultra-careful? \$\endgroup\$
    – Hektor
    Commented Aug 14, 2022 at 6:27
  • \$\begingroup\$ Depending on frequencies, etc., I'd be tempted with something like 10nF and 1uF or similar. But as Dave explains, it'll depend on package size, etc., so every case is different. Unless you're doing something super fancy, you could just use a single ~100nF and leave it at that. A single ~220nF is also a popular choice. I'm not sure what you mean by bypassing on ground pins? Surely both sides would just be ground? \$\endgroup\$
    – M1GEO
    Commented Aug 15, 2022 at 12:16

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