Substrate noise passive cancellation method for buck converter

US8179187B2 · kind B2 · utility

Assignee

• Freeescale Semiconductor, Inc. · US

Inventors

• Hongwei Zhao · Qinhuangdao City, CN
• Jian Yang · State College, US
• Iven Zheng · Beijing, CN
• Tommy Mao · Beijing, CN
• Waley Li · Beijing, CN

Key dates

• Filing date: Oct 13, 2009
• Grant date: May 15, 2012
• Expiry date: Oct 9, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D84/401

Abstract

A method for passive cancellation of substrate noise for a buck converter uses an on-chip capacitor to reduce the substrate noise. The capacitor achieves a close-magnitude noise with opposite phase for better noise cancellation effect in the substrate. The capacitor can be realized as a MOS capacitor, NMOS isolation ring n-well capacitor, n-well junction capacitor, isolated p-well junction capacitor, etc. The capacitor is easy to implement. Further, bond wire parasitic inductance in the buck converter is used to reduce substrate noise.