Differential Reference Voltage Circuit for Precise Peak Detection
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Solution Overview
Problem
Conventional peak detecting circuits suffer from large detection errors for small signal amplitudes, resulting in inadequate accuracy and linearity, failing to meet high accuracy requirements in communication systems.
Innovation Solution
A circuit for generating differential reference voltages, comprising a common-mode extraction circuit, operational amplifiers, voltage dividing resistors, and a direct current power source, which extracts a common-mode level and generates differential reference voltages to improve signal amplitude detection precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional peak detecting mechanism is used, then the circuit structure is simple, but the detection accuracy and linearity are insufficient for small signal amplitudes
Solution Approach 1:
The peak detecting circuit is divided into multiple functional modules: common-mode extraction circuit, differential signal processing circuit, and peak detecting circuit. Each module performs a specific function, allowing the system to achieve high detection accuracy through coordinated operation of specialized sub-circuits while maintaining manageable overall complexity.
Solution Approach 2:
A differential signal processing circuit is introduced as an intermediary between the common-mode extraction circuit and the peak detecting circuit. This intermediary circuit converts the single-ended common-mode signal into a differential signal, enabling the peak detecting circuit to operate with higher precision by utilizing the differential signaling approach which provides better noise immunity and accuracy.
2Manufacturing precision
If a conventional peak detecting mechanism is used, then the circuit is easy to manufacture, but the linearity and accuracy do not meet high accuracy requirements
Solution Approach 1:
The circuit transforms the detection approach by changing the signal parameters - converting from direct single-ended peak detection to differential peak detection. By changing the signal representation to differential mode and using matched resistor pairs, the circuit achieves superior linearity and accuracy characteristics that meet high-precision requirements.
Solution Approach 2:
The common-mode extraction circuit uses asymmetric resistor configurations (R1, R2, R3, R4 with specific relationships) to extract the common-mode signal while the differential signal processing circuit uses symmetric differential pairs. This controlled asymmetry in the common-mode path combined with symmetry in the differential path enables precise signal separation and accurate peak detection.
Data Source
AI summary
A circuit for generating differential reference voltages, a circuit for detecting a signal peak, and an electronic device. In the circuit for generating reference voltages, a common-mode extraction circuit receives a first differential signal and a second differential signal, extracts a common-mode level from the first differential signal and the second differential signal, and applies the common-mode level to a non-inverting input terminal of a first operational amplifier. The first operational amplifier, a main control switch, a first voltage dividing resistor, a second voltage dividing resistor, and a first direct current power source constitute a feedback loop, to generate differential reference voltages matching with the common-mode level. Adjusting a current provided by the first direct current power source can change the differential reference voltages, obtaining a reference for to-be-detected amplitude of the signals. Signal amplitude is detected with high precision, and detection reliability of a peak detecting circuit is improved.