Switchable Resistor Amplifier Circuit for Wide Dynamic Range
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Solution Overview
Problem
Conventional amplifier circuits for photodiodes require complex and large-scale structures to accommodate a wide dynamic range, leading to the use of expensive components and increased complexity due to the need for numerous high-resistance resistors and analog switches, which are costly and prone to leakage errors.
Innovation Solution
An amplifier circuit with a simple structure that uses a voltage-dividing resistor circuit and feedback resistor circuit, featuring a series connection of resistors and switches, allowing for dynamic resistance switching to achieve a wide range without excessive high-resistance components or parallel switches, thereby reducing costs and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional amplifier circuits use complex and large-scale circuit structures to accommodate wide dynamic range, then the dynamic range is improved, but the device complexity and cost increase
Solution Approach 1:
The feedback resistor circuit is segmented into multiple discrete resistor units (first through fourth resistor units) that can be selectively connected. This segmentation allows the circuit to achieve multiple resistance values without requiring a single complex high-resistance component, thereby reducing circuit complexity while maintaining wide dynamic range capability.
Solution Approach 2:
The circuit employs switching elements to dynamically reconfigure the feedback resistor circuit, allowing transition between different resistance configurations. This dynamic reconfiguration enables the amplifier to adapt its gain and accommodate wide dynamic range without requiring a permanently complex circuit structure.
2Adaptability or versatility
If conventional amplifier circuits use numerous high-resistance resistors and analog switches, then the dynamic range is improved, but the cost and leakage errors increase
Solution Approach 1:
Instead of using a single high-resistance resistor or few high-value components, the feedback path is divided into multiple lower-resistance resistor units connected in series/parallel combinations. This segmentation reduces the resistance value of individual components, thereby minimizing leakage currents and associated errors while still achieving the required overall resistance range through configuration switching.
3Adaptability or versatility
If conventional amplifier circuits use numerous high-resistance resistors and analog switches, then the dynamic range is improved, but the cost increases
Solution Approach 1:
The feedback resistor circuit is divided into multiple standard-value resistor units that can be selectively connected. This approach allows the use of common, low-cost resistor values rather than requiring expensive custom high-resistance components. The segmented architecture enables cost-effective implementation of wide dynamic range through standard component selection and switching.
Solution Approach 2:
The invention replaces expensive high-resistance resistors and analog switches with a combination of standard-value resistors and switching elements. By using multiple lower-cost resistor units in configurable arrangements, the circuit achieves the same functional capability at reduced component cost.
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 enables a wide dynamic range with fewer expensive components and reduced leakage errors, simplifying the circuit and reducing the size of the printed circuit board, while maintaining high accuracy and handling a broad range of input currents effectively.
Implementation Method 1
a photodiode photoelectrically converts this light and outputs an electric signal based on the quantity of light thereof
Implementation Method 2
a voltage-dividing resistor circuit electrically connected to the output terminal, having a voltage-dividing terminal outputting a potential obtained by voltage-dividing a potential of the output terminal
Data Source
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AI summary
An amplifier circuit (100) comprises: an operational amplifier (Ul) including two input terminals and an output terminal; a voltage-dividing resistor circuit (101) electrically connected to the output terminal and comprising a voltage-dividing terminal configured to output a potential obtained by voltage-dividing a potential of the output terminal and a feedback resistor circuit (102) electrically connected to the voltage-dividing terminal and one of the two input terminals. The voltage-dividing resistor circuit (101) comprises a plurality of resistors (R4-R7) each comprising terminals and a plurality of switches (S2-S4). The plurality of resistors (R4-R7) includes a first resistor (R4) and a second resistor (R5-R7; R6; R7). The first resistor (R4) comprises a terminal corresponding to the voltage-dividing terminal. The plurality of switches (S2-S4) are configured to switch between terminals corresponding to the voltage-dividing terminal from among the plurality of terminals of the plurality of resistors (R4-R7).