Output buffer

An output buffer (200) having a protection circuit (228, 230, 232) which adjusts control of an output drive circuit (224,226) in response to external voltages on the output pin (202). When the output pin is in a tri-state condition and receives an external voltage which is outside a predetermined vo...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: CODDINGTON JOHN DEANE, PELLEY, III PERRY H
Format: Patent
Sprache:eng
Schlagworte:
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:An output buffer (200) having a protection circuit (228, 230, 232) which adjusts control of an output drive circuit (224,226) in response to external voltages on the output pin (202). When the output pin is in a tri-state condition and receives an external voltage which is outside a predetermined voltage range, the protection circuit adjusts the voltage on the control gate of a transistor (224) in the output drive circuit. The protection circuit maintains the voltage across the transistor within the tolerance of the transistor. In one embodiment, the output drive circuit has pullup (204) and pulldown (206) portions. The output buffer provides a high voltage output driver having low voltage devices.