Mos output driver circuit avoiding hot-electron effects

Claim 1

An integrated-circuit output circuit for combining logic output signals from first and second logic input terminals to control the voltage on an output node, comprising: a first output transistor having a first terminal connected to ground, a second terminal connected to said output node and a gate connected to said first logic input terminal; and a second output transistor having a first terminal connected to said output node, a second terminal connected to a power supply node and a gate connected to said second logic input terminal; characterized in that: a third output transistor having a gate, said third output transistor being connected between said second terminal of said second output transistor and said power supply node, and further characterized in that compensating means coupled to said output node and substantially responsive only to negative voltage on said output node for controlling said third output transistor controls said gate of said third output transistor to switch the transconductance of said third output transistor between a first transconductance when said voltage on said output node is greater than or equal to ground and a second transconductance when said voltage on said output node is less than ground.