Example of Creating a Custom Symbol Using a Standard Symbol

PartQuest Portal Subscription: Essential or Professional

This example steps you through the process of using the Symbol Creator tool to edit a standard symbol to replace the one that comes with the LM741CNNS/NOPB PartQuest Portal part.

Procedure

  1. In the search field at the top of the Search page, enter LM741CNNS/NOPB, and then click the Search button.
  2. Click the More button in the short part description.
  3. Click the Choose Symbol button in the detailed description section.

    The Choose Symbol dialog box displays.

  4. Expand the Amplifier category if it is not already expanded, and then click the "Differential I/ Single Ended O" standard symbol.

    The Symbol Creator displays with a symbol named “Texas_Instruments_LM741CN_NOPB”.

  5. Click the Edit button to the right of the name.
  6. Select the Custom field, edit the name to be “TI_LM741CN_NOPB”, and then click the Ok button.
  7. Click the Datasheet () button to access the PDF of the datasheet.

    The datasheet displays the details about this part, such as the functional pin names and the terminal numbering. As shown in the datasheet section called “Pin Configuration and Functions”, pin 1 on the package has a functional name of Offset Null.

    The default symbol in the Symbol Creator Symbol Preview pane includes optional pins as shown on the left in the following figure:



  8. Hide the optional pins by clicking the Disable All button.

    The Symbol Creator tool hides the optional pins, as shown on the right in the previous figure.

    This part utilizes two of the optional pins we removed, both called Offset Null in the datasheet, pins 1 and 5.

  9. In the Terminal(Pin) List section, scroll until you can see the two Offset pins, and then toggle the Disabled switch to Enabled for each to add them back to the symbol.
  10. Expand the Terminal(Pin) list section by clicking the Expand () button on the bottom right side of the Terminal(Pin) List region to see all the properties.
  11. In the Terminal # column of the Terminal(Pin) List, click to enter the footprint terminal number for each pin as defined in the datasheet (repeated in the following table).

    Datasheet pin #

    Datasheet Name

    JEDEC Name in Terminal(Pin) List

    2

    INVERTING INPUT

    Negative Input

    3

    NONINVERTING INPUT

    Positive Input

    1

    OFFSET NULL

    Offset Node 1

    5

    OFFSET NULL

    Offset Node 2

    6

    OUTPUT

    Output

    7

    V+

    +V

    4

    V-

    -V

    Each functional name now corresponds to the matching footprint terminal number, as shown in the following figure:



    Tip

    Click the Collapse () button to see more of the Symbol Preview window.

    As shown in the datasheet, this part has a No Connect pin on terminal 8. On the bottom of the Terminal(Pin) List, in the Unassigned Footprint Terminals area, the Symbol Creator tracks how many pins are currently unassigned. In this example, there is one unassigned terminal.

  12. Click the Add button to the right of the Unassigned Footprint Terminals text entry box.

    The Symbol Creator adds the NC terminal to the Terminal(Pin) List.

  13. Enter the footprint terminal number (8) for the NC pin.
  14. In the User-defined Name column of the Terminal(Pin) List, double-click the “Vout” entry to select it, and then type “AmplifierOutputPin” to rename it.

    The symbol size adjusts to accommodate the longer name.

    User-defined pin names can be repeated because these are labels only. The real pin names are displayed in the JEDEC Name column.

  15. Click the < Done button below the Terminal(Pin) List section when you are finished creating your symbol.