US 6,552,582 B1 · Source follower for low voltage differential signaling

Abstract

A source follower circuit for low voltage differential signaling (LVDS) has a low power consumption, low noise, and the ability to drive a highly capacitive load at an output port of an integrated circuit (IC). The source follower circuit includes a first p-channel transistor having a drain coupled to a supply voltage and a gate coupled to a first input; a second p-channel transistor having a drain coupled to the supply voltage and a gate coupled to a second input which is complementary to the first input; a third p-channel transistor having a gate coupled to the second input, a source coupled to ground, and a drain coupled to a source of the first p-channel transistor which forms a first output; and a fourth p-channel transistor having a source coupled to the ground and a drain coupled to a source of the second p-channel transistor which forms a second output which is complementary to the first output. Advantageously, the output signals of the circuit are referenced to ground and are less affected by power supply variations.

Claims11

Dependent claims

An integrated circuit (IC) having a source follower comprising:

a first transistor having a drain coupled to a first supply voltage and a gate coupled to a first input;
a second transistor having a drain coupled to the first supply voltage and a gate coupled to a second input which is complementary to the first input;
a third transistor having a gate coupled to the second input, a source coupled to a second supply voltage which is less than the first supply voltage, and a drain coupled to a source of the first transistor and forming a first output;
a fourth transistor having a source coupled to the second supply voltage, a drain coupled to a source of the second transistor and forming a second output which is complementary to the first output;
a first pull-up transistor coupled between the first output and the first supply voltage;
and a second pull-up transistor coupled between the second output and the first supply voltage.

3 more elements

Dependencies are inferred from the claim text.

Source follower for low voltage differential signaling

Life of this patent

Source follower for low voltage differential signaling

Life of this patent

Abstract

Claims11