Single-Ended Input Buffer With Symmetric Differential Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Differential input buffers in integrated circuits often operate non-symmetrically when receiving single-ended input signals, leading to inconsistent responses to signal transitions and limited frequency capabilities compared to differential inputs.
Innovation Solution
A differential input buffer design that includes capacitive coupling between the gates of transistors in each amplifier, mimicking the operation of receiving complementary signals, ensuring symmetrical response to single-ended input signals by replicating the transition behavior of differential inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a differential input buffer uses a symmetrical differential amplifier structure, then it operates symmetrically when receiving complementary signals, but it responds slower to single-ended input signals compared to differential inputs
Solution Approach 1:
The patent applies asymmetry by introducing a capacitive coupling element between the gates of the differential pair transistors. This asymmetric modification to the otherwise symmetric differential amplifier structure enables the buffer to respond faster to single-ended input signals while maintaining symmetrical operation characteristics when receiving complementary signals.
2Adaptability or versatility
If a differential input buffer receives single-ended input signals, then it can interface with single-ended signal sources, but it operates non-symmetrically leading to inconsistent responses to signal transitions
Solution Approach 1:
The patent introduces a capacitive coupling element as an intermediary between the single-ended input signal and the differential amplifier inputs. This capacitor couples the single-ended input to both gates of the differential pair, creating a virtual differential signal that enables symmetrical operation while maintaining compatibility with single-ended signal sources.
3Productivity
If a differential input buffer is designed for high frequency operation, then it can handle higher frequency signals, but it requires differential inputs to maintain symmetrical operation and fast response
Solution Approach 1:
The patent achieves universality by designing a buffer that can accept both single-ended and differential input signals while maintaining high frequency handling capability. The capacitive coupling structure allows the buffer to operate symmetrically with differential inputs for maximum speed while also being adaptable to single-ended inputs without significant performance degradation.
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 buffer achieves faster response times and symmetric operation for single-ended inputs, enabling higher frequency handling and consistent signal processing, as demonstrated by the comparison with conventional buffers in FIG. 2.
Implementation Method 1
The capacitor couples an input signal to a gate of the transistor
Data Source
AI summary
Embodiments are described including those pertaining to an input buffer having first and second complementary input terminals. One example buffer has a symmetrical response to a single input signal applied to the first input terminal by mimicking the transition of a signal applied to the second input terminal in the opposite direction. The buffer includes two amplifier circuits structured to be complementary with respect to each other. Each of the amplifier circuits includes a first transistor having a first input node that receives an input signal transitioning across a range of high and low voltage levels, and a second transistor having a second input node that receives a reference signal. The first input node is coupled to the second transistor through a capacitor to mimic the second input node transitioning in the direction opposite to the transition of the input signal.