Switched-Capacitor Integrator Amplifier With Current-Reuse Low-Noise Topology
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional amplifiers in sampling circuits face challenges in achieving a balance between current consumption and transconductance while maintaining low noise performance, often requiring high current consumption for sufficient transconductance or limited transconductance with reduced current consumption, and have limited noise performance.
Innovation Solution
The amplifier arrangement employs multiple differential transistor pairs with complementary types, forming a symmetric structure with multiple stages, allowing reuse of supply current and distributing noise contributions to reduce noise at output terminals while maintaining transconductance, using a combination of differential and complementary stages with shared current paths and tail sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional amplifier concepts use high current consumption, then sufficient transconductance is achieved, but noise performance is limited and current efficiency deteriorates
Solution Approach 1:
The amplifier is divided into multiple differential stages (first differential stage, second differential stage, first complementary differential stage, second complementary differential stage), each contributing to the overall transconductance. This segmentation allows the supply current to be reused across multiple transistor pairs, achieving sufficient total transconductance without requiring high current consumption in a single stage.
Solution Approach 2:
The supply current serves multiple functions by being reused in multiple differential transistor input pairs across different stages. A single current source provides biasing for multiple transistor pairs, making the current consumption efficient while maintaining adequate transconductance across all input terminals.
2Use of energy by moving object
If conventional amplifier concepts reduce current consumption, then current efficiency improves, but transconductance becomes limited
Solution Approach 1:
By segmenting the amplifier into multiple differential stages with complementary transistor types, the patent achieves cumulative transconductance from multiple transistor pairs that share a common supply current. This allows low current consumption per stage while maintaining sufficient total transconductance.
Solution Approach 2:
The amplifier uses a composite structure combining differential and complementary differential stages with opposite conductivity types. This composite architecture multiplies the effective transconductance contribution from the shared supply current, achieving high total transconductance with low current consumption.
3Speed
If conventional amplifier concepts increase transconductance, then speed improves, but noise contribution increases
Solution Approach 1:
The amplifier is segmented into multiple stages where noise contributions from individual transistor pairs are distributed and partially canceled due to the differential and complementary structures. This allows achieving high transconductance for speed while the segmented architecture reduces the overall noise contribution compared to a single high-gm stage.
Solution Approach 2:
The patent converts the potentially harmful noise contributions from multiple transistor pairs into a benefit through the differential and complementary stage structures. Noise from individual transistors is differentialized and canceled at the output, transforming what would be harmful noise into a signal processing advantage while maintaining high transconductance.
4Adaptability or versatility
If conventional amplifier concepts use single input terminal pairs, then device complexity is reduced, but adaptability to different common mode voltages deteriorates
Solution Approach 1:
Each differential stage is designed to handle specific common mode voltage ranges, making the amplifier universally applicable to different input signal conditions. The multiple input terminal pairs allow the amplifier to adapt to various common mode voltages while maintaining proper operation, with each stage serving a specific voltage range.
Solution Approach 2:
The amplifier is segmented into multiple differential stages, each with its own input terminal pair optimized for specific common mode voltage ranges. This segmentation provides adaptability to different voltage conditions while keeping each individual stage relatively simple in structure.
Data Source
AI summary
An amplifier arrangement has a first differential stage with a first transistor pair, a second differential stage with a first and a second transistor pair, each pair having a common source connection. The amplifier arrangement further has a first complementary differential stage with a transistor pair having opposite conductivity type, and a second complementary differential stage with a first and a second transistor pair of the complementary conductivity type. The first and the second complementary differential stage are connected symmetrically compared to the first and the second differential stage. The transistors of the second differential stage and the second complementary differential stage are symmetrically connected to form respective first, second, third and fourth current paths. A pair of output terminals is coupled to the first and the fourth current path. Gate terminals of the transistors are coupled to a respective pair of input terminals.