Transconductor Filter Circuit Low Output Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing transconductor circuits with high output impedance lack low pass filtering capabilities without increasing power consumption, which is a limitation in communications applications.
Innovation Solution
A transconductor and filter circuit design that converts differential input voltage into differential output current and further filters it to achieve low output impedance, incorporating a front end module and a filter module with resistor and capacitor configurations to implement low pass filtering without significant complexity or power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If emitter followers are used to buffer the output, then output impedance is lowered, but low pass filtering capabilities are not achieved without increasing power consumption
Solution Approach 1:
The patent combines the output buffering function and low-pass filtering function into a single integrated circuit stage. The emitter followers provide output impedance lowering while capacitors connected to their outputs provide the low-pass filtering action, eliminating the need for separate filtering stages and reducing overall power consumption compared to using emitter followers alone or adding separate filtering circuits.
2Adaptability or versatility
If filtering components are added to achieve low pass filtering, then filtering capability is improved, but circuit complexity increases
Solution Approach 1:
The filtering function is merged into the existing output buffer stage by adding capacitors in parallel with the emitter follower outputs. This integration approach provides low-pass filtering capability without requiring separate filtering circuits, thereby minimizing the increase in circuit complexity while achieving the desired filtering performance.
Solution Approach 2:
The output stage is designed to perform multiple functions simultaneously: the emitter followers provide impedance transformation and buffering, while the associated capacitors provide low-pass filtering. This multi-functionality reduces the need for additional dedicated filtering components and simplifies the overall circuit architecture.
Data Source
AI summary
A transconductor and filter circuit is described. In one embodiment, a front end module within the transconductor and filter circuit converts a differential input voltage signal into a differential output current and supplies the output current at a differential output. A filter module coupled to the differential output of the front end module receives the differential output current, converts the output current into an intermediary differential voltage, and filters the differential voltage to obtain a filtered differential output voltage signal having low output impedance.