I'm stuck trying to find an oscillator chip which can be used to provide a clock to a W65C02S at, say, 12MHz.

This is the S7D12.000000A20F30T - with 12MHz output, 5V input.

enter image description here

So now my only question is, what is that tri-state buffer pin doing? The only documentation I can find is here: https://jlcpcb.com/partdetail/361053-S7D12000000A20F30T/C386965 Can I leave it unconnected - what would the default circuit be? Is that pin for debugging/disabling the chip?

Right now the only thing I can't do is supply the clock signal to my circuit. All help greatly appreciated.

UPDATE: Stumbled on this excellent and highly relevant question on the tri-state pin - What is the purpose of a tri-state pin in a Oscillator - which states that a tri-state pin on an oscillator chip is generally used for enabling/disabling the clock and therefore presumably could easily be held high for an astable clock signal, such as that supplied to a CPU chip.

Possibly answered my Q with this revelation, but any tips on additional load capacitors/ any feed resistor would be most welcome, though I realize they are possibly unnecessary here.


1 Answer 1


Follow the link to the actual datasheet from the URL you posted and you'll see the statement:

Notes: PIN 1 connected to Vdd or floating, the product is working properly;connected to GND,stops working

So leave it floating if you like, or pull up to Vdd with a resistor if you prefer.

Note that some enable pins are active high and some are active low, so always check the datasheet for the specific part to see how to use it.

  • \$\begingroup\$ Oh I missed that line, oops. Thanks for the answer. Any tips on whether I would need load capacitors or a feed resistor, or are they components generally only necessary when building a clock circuit from the round up usin only a crystal and discrete components? \$\endgroup\$
    – Hektor
    Aug 18, 2022 at 12:18
  • 1
    \$\begingroup\$ Oscillators like these provide logic-level outputs to drive other devices directly, so no other components are needed other than a decoupling capacitor across the supply pins. \$\endgroup\$
    – Finbarr
    Aug 18, 2022 at 12:22

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