Correction of delay-based metric measurements using delay circuits having differing metric sensitivities

US7548823B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Harmander Singh · Austin, US
• Alan J. Drake · Round Rock, US
• Fadi H. Gebara · Austin, US
• John P. Keane · Marietta, US
• Jeremy D. Schaub · Sleepy Hollow, US
• Robert M. Senger · Tarrytown, US

Key dates

• Filing date: May 18, 2007
• Grant date: Jun 16, 2009
• Expiry date: May 18, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/3016
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Correction of delay-based metric measurements using delay circuits having differing metric sensitivities provides improved accuracy for environmental and other circuit metric measurements that used delay lines. A delay line measurement, which may be a one-shot measurement or a ring oscillator frequency measurement is performed either simultaneously or sequentially using at least two delay lines that have differing sensitivities to a particular metric under measurement. A correction circuit or algorithm uses the measured delays or ring oscillator frequencies and corrects at least one of the metric measurements determined from one of the delays or ring oscillator frequencies in conformity with the other delay or ring oscillator frequency. The delays may be inverter chains, with one chain having a higher sensitivity to supply voltage than the other delay chain, with the other delay chain having a higher sensitivity to temperature. Temperature results can then be corrected for supply voltage variation and vice-versa.