SAR ADC Capacitor Array With Passive Gain Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional SAR ADCs with active programmable gain amplifiers (PGAs) require high accuracy and power, increasing the total cost of the circuit due to the complexity of these amplifiers.
Innovation Solution
A SAR ADC with an inherent passive PGA function, utilizing a first and second capacitor array, switch modules, a comparator, and a SAR controller to perform both analog-to-digital conversion and amplification, eliminating the need for a dedicated active PGA by adjusting the gain through control signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dedicated active PGA is used for signal amplification, then amplification accuracy is improved, but power consumption and circuit cost increase
Solution Approach 1:
The patent combines the PGA amplification function with the SAR ADC conversion function into a single integrated circuit module. The capacitor arrays and switch modules perform both signal amplification and analog-to-digital conversion operations, eliminating the need for a separate dedicated PGA and reducing overall power consumption while maintaining amplification accuracy
Solution Approach 2:
The SAR ADC circuit is designed with multi-functionality, where the same capacitor arrays and switch modules can operate in different modes to achieve both PGA amplification and ADC conversion. The circuit responds to different control signals to switch between amplification operations and conversion operations, making one circuit serve multiple purposes
2Power
If a dedicated active PGA is used for signal amplification, then amplification function is improved, but device complexity increases
Solution Approach 1:
The patent merges the PGA amplification function with the SAR ADC conversion function into a single integrated circuit module. The capacitor arrays and switch modules perform both signal amplification and analog-to-digital conversion operations, eliminating the need for a separate dedicated PGA and reducing overall power consumption while maintaining amplification accuracy
Solution Approach 2:
The SAR ADC circuit is designed with multi-functionality, where the same capacitor arrays and switch modules can operate in different modes to achieve both PGA amplification and ADC conversion. The circuit responds to different control signals to switch between amplification operations and conversion operations, making one circuit serve multiple purposes
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 solution reduces power consumption and eliminates the need for an additional active PGA, allowing for efficient analog-to-digital conversion and amplification while maintaining control over the gain, thus lowering the overall circuit cost.
Implementation Method 1
a first capacitor array, a first input capacitor, a first switch module, a second capacitor array, a second input capacitor
Data Source
AI summary
A successive approximation register (SAR) analog-to-digital converter (ADC) includes a first capacitor array, a first input capacitor, a first switch module, a second capacitor array, a second input capacitor, a second switch module, a comparator and a SAR controller. The SAR ADC is operated under sampling phases and amplifying phases many times to perform amplifying operations and ADC operations upon input signals to generate digital output data. In addition, because the SAR ADC has both an amplification function and an ADC function, a circuit utilizing the SAR ADC does not require an additional active PGA, and a power consumption of the circuit is decreased.