Patent ID: 8664993
Filing Date: 2014-03-04
Classification: H03K

Abstract:
1. A phase interpolator, comprising: a differential to single-ended converter, having two input-ends to receive a differential signal comprising a first signal and a second signal, respectively, and converting the differential signal into an output clock signal in single-ended form; a load circuit, coupled to the input-ends of the differential to single-ended converter; a first differential pair, coupled to the input-ends of the differential to single-ended converter, wherein a control-end of the first differential pair receives a first input clock; a second differential pair, coupled to the input-ends of the differential to single-ended converter, wherein a control-end of the second differential pair receives a second input clock; a current source, generating a reference current, wherein the reference current is proportional to the frequency of the first input clock; and a switch pair, coupled between the first and the second differential pairs and the current source, wherein a control-end of the switch pair receives a control signal in differential form.