Implementing compact current mode logic (CML) inductor capacitor (LC) voltage controlled oscillator (VCO) for high-speed data communications

Patent metadata

Field	Value
Publication number	US-8994460-B2
Application number	US-201213675650-A
Country	US
Kind code	B2
Filing date	Nov 13, 2012
Priority date	Nov 13, 2012
Publication date	Mar 31, 2015
Grant date	Mar 31, 2015

Abstract

A method and a phase locked loop (PLL) circuit for implementing compact current mode logic inductor capacitor voltage controlled oscillator for high speed communications, and a design structure on which the subject circuit resides are provided. The PLL circuit includes a current mode logic (CML) inductor capacitor (LC) Voltage Controlled Oscillator (VCO). The PLL circuit includes a reference circuit generates a virtual ground node for biasing noise sensitive components, providing level shifted VCO increment and decrement tuning values from a phase detector coupled by a respective resistor to tune a varactor of the LC VCO, and providing a loop filter function. The virtual ground node tracks a logic power supply noise, incurring no jitter penalty, and eliminating the need for a separate power supply for the PLL circuit.

First claim

What is claimed is:

1. A method for implementing a compact current mode logic inductor capacitor voltage controlled oscillator for high speed communications comprising:
providing a PLL circuit including a current mode logic (CML) inductor capacitor (LC) Voltage Controlled Oscillator (VCO);
providing a reference circuit generating a virtual ground node for biasing noise sensitive components using a logic power supply, said virtual ground node tracking logic power supply noise, in…

Assignees

• IBM

Inventors

• Kesselring Grant P
• Strom James D
• Van Goor Kenneth A
• Cheruiyot Kennedy K

Classifications

• H03L7/0992 Primary

  Electricity · mapped topic

• H03L7/085

  Electricity · mapped topic

• H03L7/099 Primary

  Electricity · mapped topic