A Frequency-Domain Analysis of Latch Comparator Offset due to Load Capacitor Mismatch

Area of Science:

• Electrical Engineering
• Analog Integrated Circuit Design

Background:

• Latch comparators are critical components in high-speed data converters.
• Offset voltage in comparators degrades overall system performance.
• Load capacitor mismatch is a significant contributor to comparator offset.

Purpose of the Study:

• To present a frequency-domain analysis of latch comparator offset.
• To investigate the impact of load capacitor mismatch on comparator offset.
• To develop a method applicable to both static and dynamic latch comparators.

Main Methods:

• Frequency-domain analysis was employed.
• The analysis focused on the offset voltage arising from load capacitor mismatches.
• The methodology was initially applied to a static latch comparator circuit.

Main Results:

• A closed-form expression for offset voltage due to capacitor mismatch was derived.
• The analysis quantifies the sensitivity of offset to capacitor mismatch in the frequency domain.
• The developed method provides insights into offset reduction techniques.

Conclusions:

• Frequency-domain analysis offers a powerful tool for understanding latch comparator offset.
• Load capacitor mismatch is a key factor influencing comparator offset.
• The presented analysis framework is extendable to dynamic latch comparators.