Time-Interleaved ADC Isolation Inductors for Kickback Settling
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Solution Overview
Problem
High-speed, high-resolution analog-to-digital converters (ADCs) face performance degradation due to voltage kickback from track-and-hold circuits, which requires additional power consumption and increased buffer area to settle, especially in time-interleaved configurations.
Innovation Solution
Incorporating isolation inductors electrically coupled to the output of the input buffer and track-and-hold circuits, which reduces voltage kickback by isolating the kickback voltage and allowing for reduced power consumption and smaller semiconductor die area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional power is supplied to the input buffer to increase bandwidth and reduce output impedance, then voltage kickback settling improves, but power consumption and buffer area increase
Solution Approach 1:
An isolation inductor is introduced as an intermediary element between the input buffer and the track-and-hold circuits. This inductor acts as a mediator that blocks the propagation of voltage kickback from the switched capacitor load back to the buffer output, thereby improving voltage settling without requiring additional buffer power or increasing buffer area.
2Reliability
If additional power is supplied to the input buffer to increase bandwidth and reduce output impedance, then voltage kickback settling improves, but buffer area increases
Solution Approach 1:
The isolation inductor serves as a compact intermediary component that provides voltage kickback isolation without requiring an increase in buffer area. By placing this small inductor in series between the buffer and the track-and-hold circuits, the buffer can maintain its original size while achieving improved voltage settling through the inductor's blocking effect.
3Productivity
If multiple T/H circuits are driven in sequence by a single buffer, then ADC conversion speed increases, but voltage kickback effects are exacerbated
Solution Approach 1:
The patent applies segmentation by dividing the connection between the single input buffer and multiple track-and-hold circuits into separate isolated paths. Each T/H circuit is connected through its own isolation inductor, which segments the harmful voltage kickback effects of each circuit, preventing them from accumulating and degrading overall ADC performance while maintaining high conversion speed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of isolation inductors significantly reduces voltage kickback, improves tracking bandwidth, and maintains high ADC performance with reduced power consumption and die area, enhancing the ADC's figure-of-merit.
Implementation Method 1
an isolation inductor electrically coupled to the output of the input buffer and at least one of the track-and-hold circuits
Data Source
AI summary
A time-interleaved circuit includes an input buffer, a plurality of track-and-hold circuits, and a plurality of isolation inductors. The input buffer is configured to receive an input signal having an input voltage and to output an output signal having an output voltage. The track-and-hold circuits are electrically coupled in parallel with each other. Each track-and-hold circuit is electrically coupled in series with the input buffer. Each isolation inductor is electrically coupled to the output of the input buffer and at least one of the track-and-hold circuits.