Gating-Based DQS Receiver With Adaptive Noise Disable
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Solution Overview
Problem
In DDR5 memory systems, the DQS receiver is susceptible to noise interference during parking periods when data strobe signals are pulled up to power voltage, leading to unknown outputs and abnormality due to the inability to distinguish small swing signals from noise.
Innovation Solution
A gating-based receiver circuit with a gating signal generator that uses an adaptive reference voltage to enable or disable the receiver based on input signal levels, employing a comparator circuit to generate a gating signal that disables the receiver during noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the DQS receiver remains active during parking period, then it can continuously monitor signals, but it becomes susceptible to noise interference and produces unknown outputs
Solution Approach 1:
The gating signal generator proactively generates gating signals before noise interference occurs by detecting when both DQS_t and DQS_c are pulled up to VDD. This preliminary action disables the receiver in advance during parking period, preventing noise from being misinterpreted as valid signals while maintaining the ability to quickly re-enable upon signal arrival
Solution Approach 2:
A gating signal is introduced as an intermediary control signal between the DQS receiver and its input signals. This gating signal acts as a mediator that selectively enables or disables the receiver based on the voltage levels of DQS_t and DQS_c, allowing the receiver to ignore noise during parking period while remaining responsive to valid data strobe signals
2Object-affected harmful factors
If a fixed threshold is used to filter noise, then simple noise filtering is achieved, but small swing data strobe signals cannot be distinguished from noise
Solution Approach 1:
The gating signal generator dynamically adjusts its noise filtering behavior based on the actual voltage levels of DQS_t and DQS_c. Instead of using a fixed threshold, the system adapts its gating decision to the current signal conditions, enabling it to distinguish between small swing valid signals and noise by detecting whether both signals are pulled up to VDD, thus providing both noise filtering and signal adaptability
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 effectively filters noise by disabling the receiver during high input signal levels, ensuring correct operation and preventing noise interference, thereby maintaining the DQS receiver's functionality.
Implementation Method 1
a comparator circuit, receiving the first input signal, the second input signal and the adaptive reference voltage, and generating a gating signal
Data Source
AI summary
A gating-based receiver circuit is provided. The receiver circuit includes a gating signal generator, receiving a first and second input signals and reference voltage to output a gating signal, wherein an adaptive reference voltage is generated by the first and second input signals and the reference voltage; and a receiver, receiving the first and second input signals and the gating signal to provide a receiver output signal. In response to both the first input signal and the second input signal being higher than the adaptive reference voltage, the gating signal disables the receiver, and in response to one of the first input signal and the second input signal being lower than the adaptive reference voltage, the gating signal enables the receiver.