Physical Circuits.

• I will build some physical circuits for you.
  • If you wish, there is some equipment in Ross 129, you may use this.
  • Please see me first.
• We will be building on a "bread board"
  • 
  • The line down the middle divides this into two parts.
    • And is generally just right for a chip to span.
  • On the sides are two wires connected the length of the board.
    • They are intended for power.
    • Plug a wire from the positive into the red row.
    • Plug a wire from the ground into the blue row.
    • Then jump from these to wires on the board to power a chip.
  • In the middle, the five holes in a row are connected to a common wire.
    • 
    • This is just a little different from the above.
    • But the brown wire at the top is the positive voltage supply
    • The yellow wire brings this down to the column
    • And the chip's top left pin is plugged into the positive.
  • Chips generally have
    • A Vcc or voltage input pin.
    • A GND or ground pin.
    • A number of input/output pins based on the circuit
  • For a given chip, you can get the Data Sheet
    • This usually shows
      • The physical layout.
      • The logic diagram.
      • The actual schematics
      • Operating Characteristics.
• Let's look at the 74LS04N, a HEX Inverter
  • The datasheet
  • There is a chip view
    • 
    • Note the indentation at the top, so you can identify the pins
    • Note the labels on the pins
  • There is a logical view
    • 
  • And a bunch of other information.
• Look at the operation of the 7404 on the digital trainer.