Patent ID: 7233175

Claim:
An amplitude limiting circuit, comprising: a differential circuit which comprises a first transistor having a control electrode, a first electrode connected to a first node and a first output node and a second electrode connected to a second node and a second output node, a second transistor having a control electrode, a first electrode connected to the first output node and a second electrode connected to the second output node, a third transistor having a control electrode connected to a first input node, a first electrode connected to the first electrode of the second transistor and a second electrode, and a fourth transistor having a control electrode connected to a second input node, a first electrode connected to the second electrode of the second transistor and a second electrode connected to the second electrode of the third transistor; a first source follower circuit which is connected to the first node and the control electrode of the second transistor, said first source follower circuit comprising a fifth transistor having a control electrode connected to the first node, first electrode supplied with a power supply voltage and a second electrode connected to the control electrode of the second transistor; and a first current source connected to the second electrode of the fifth transistor and supplied with a ground voltage; and a second source follower circuit which is connected to the second node and the control electrode of the first transistor, said second source follower circuit comprising a sixth transistor having a control electrode connected to the second node, a first electrode supplied with the power supply voltage and a second electrode connected to the control electrode of the first transistor; and a second current source connected to the second electrode of the sixth transistor and supplied with the ground voltage; wherein the differential circuit further comprises: a third current source connected to the second electrodes of the third and fourth transistors and supplied with the ground voltage.