source driver, (current-)

A unipolar output whose primary connection within the integrated circuit is through an active device to the most positive (least negative) supply voltage.

NOTE 1 When the active device is in its on state, the output voltage approaches the voltage of the supply to which it is connected by the active device; when the device is in its off state, the output is pulled down to the least positive (most negative) supply voltage through the external circuit to which the output is connected.

NOTE 2 Examples of source drivers are pnp open-collector, npn emitter-follower, npn open-emitter, p‑channel open-drain, n‑channel open-source, and n‑channel source-follower outputs.

Graphic symbol (ref. ANSI/IEEE Std 91 and IEC 617‑12):

NOTE The bar above the diamond indicates that the output is at the high logic level when the device is in its on state.


JESD99B, 5/07