Patent ID: 7148724
Filing Date: 2006-12-12
Classification: H03K

Abstract:
1. A signal output circuit comprising: a first transistor of a first conduction type with a base connected to an input signal terminal; a first constant current source including a second transistor of said first conduction type with a collector connected to an emitter of said first transistor, thus constituting a first emitter follower circuit with said first transistor; a third transistor of said first conduction type with a base connected to said input signal terminal; a second constant current source including a fourth transistor of said first conduction type with a collector connected to an emitter of said third transistor, thus constituting a second emitter follower circuit with said third transistor; and a comparator that receives an output signal from said first and said second emitter follower circuit; wherein said comparator includes a fifth transistor of a second conduction type with a collector connected to a base of said fourth transistor, and driven by an output signal from said first emitter follower circuit, a sixth transistor of said second conduction type constituting a differential pair with said fifth transistor, and driven by an output signal of said second emitter follower circuit, a resistance element connecting respective emitters of said fifth and said sixth transistor, and a current mirror circuit connected to respective collectors of said fifth and said sixth transistor.