question about pic16f628

Discussion in 'The Projects Forum' started by ht systems, Aug 16, 2011.

  1. ht systems

    Thread Starter Member

    Aug 2, 2011
    71
    1
    hello , how could i choose the value of the crystal and do i need to put an amplifier on the output to lead an AND gate or NOT gate ?
     
  2. upand_at_them

    Active Member

    May 15, 2010
    246
    29
    The crystal is up to you, limited by the datasheet spec. If you're only driving a few gates, you don't need a buffer on the output.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    If you use a PIC16F628A instead, they have an internal 4MHz oscillator, so you would not need a crystal unless you need better than ~1% accuracy.

    The I/O pins can source or sink ±20mA+, but there is also a package limit. See the Electrical Specifications section in the datasheet.
     
  4. ht systems

    Thread Starter Member

    Aug 2, 2011
    71
    1
    thank you , your words help me
     
  5. eblc1388

    Senior Member

    Nov 28, 2008
    1,542
    102
    16F628 also has an internal 4MHz RC oscillator, albeit not factory calibrated to within 1% accuracy.

    [​IMG]
     
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