ADC Amplifier Pre-Biasing for Single-Cycle Initialization
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Solution Overview
Problem
Some analog to digital converters require multiple cycles to initialize for data conversion, leading to inefficiencies and delays in processing analog signals.
Innovation Solution
The use of a redundant sign division architecture with a specific amplifier and initialization circuit that biases the outputs during initialization to a common mode feedback voltage, allowing for immediate conversion by utilizing switch capacitor circuits and a common mode feedback sense circuit to generate residue voltages efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional amplifiers are used in analog to digital converters, then the converter can perform data conversion, but it requires multiple cycles (3-4 cycles) to initialize before conversion can begin
Solution Approach 1:
The patent applies preliminary action by performing initialization of the amplifier outputs to a predetermined voltage level before the conversion process begins. The initialization circuit pre-charges or pre-biases the differential output nodes to a common-mode voltage, ensuring the amplifier is ready for immediate conversion operation. This preliminary preparation eliminates the need for multiple initialization cycles, allowing the converter to start processing signals immediately upon receiving the input signal.
2Loss of time
If initialization circuits are added to reduce initialization cycles, then conversion readiness is improved, but device complexity increases
Solution Approach 1:
The patent merges the initialization function with the existing amplifier structure by integrating an initialization circuit that shares common nodes and power supply connections with the differential amplifier. The initialization circuit uses the same power supply voltage and connects to the same output nodes as the amplifier, consolidating functions rather than adding completely separate initialization hardware. This merging approach reduces overall device complexity while achieving fast initialization.
3Device complexity
If the amplifier outputs are not pre-biased, then the circuit design is simpler, but the converter requires multiple cycles to reach conversion readiness
Solution Approach 1:
The patent ensures continuity of useful action by maintaining the amplifier outputs in a ready state through continuous pre-biasing via the initialization circuit. Rather than allowing the outputs to float or require re-initialization between conversions, the initialization circuit continuously maintains the outputs at the predetermined voltage level, enabling uninterrupted conversion operation. This continuous preparation eliminates idle cycles and maximizes processing efficiency.
Data Source
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AI summary
An analog to digital converter has an input circuit (103), a computation circuit (105), an initialization circuit (333, 335, and 337), and an output circuit (107). The input circuit is for receiving an analog signal and has a pair of outputs. A computation circuit has a pair of inputs coupled to the pair of outputs. The computation circuit has an amplifier having a pair of complementary outputs (Outp, Outn). The initialization circuit is coupled to the complementary outputs and is for biasing the complementary outputs at a time prior to the computation circuit beginning a computation on the analog signal. The output circuit is coupled to the pair of complementary outputs and provides a digital signal.