Input Receiver Circuit Without Shunt Resistor Leakage
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Solution Overview
Problem
Conventional input receivers in DRAM devices face performance degradation due to power consumption issues caused by leakage current from shunt resistors, which hinder high-speed operations.
Innovation Solution
The input receiver design replaces shunt resistors with an inverter circuit structure connected in parallel to a rail-to-rail amplifier circuit, allowing for high-speed operation while minimizing power consumption by using current source circuits and inverter circuits to manage bias signals and voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shunt resistor is used in the input receiver to enable correct operations in high-speed environment, then the operation correctness is improved, but power consumption increases due to leakage current
Solution Approach 1:
The patent removes the shunt resistor from the circuit and replaces it with an inverter circuit connected in parallel to the rail-to-rail amplifier. This extraction eliminates the leakage current path through the resistor while maintaining the necessary biasing function through the inverter's transistor structure, thereby resolving the contradiction between operational correctness and power consumption.
Solution Approach 2:
The patent substitutes the passive resistive biasing mechanism with an active transistor-based inverter circuit. The inverter uses voltage-controlled switching characteristics to provide biasing without the continuous leakage current inherent in resistive designs, achieving both high-speed operation and reduced power consumption.
2Use of energy by moving object
If an inverter circuit is connected in parallel to the rail-to-rail amplifier to replace the shunt resistor, then power consumption is reduced, but circuit complexity increases
Solution Approach 1:
The inverter circuit performs multiple functions simultaneously: it provides biasing for the rail-to-rail amplifier, enables high-speed operation, and reduces power consumption. By integrating these functions into a single circuit block rather than adding separate components, the patent minimizes the increase in overall circuit complexity while achieving the desired power reduction.
3Speed
If the inverter circuit is configured to operate with voltage swing equal to the amplified signal, then high operating speed is achieved, but the design precision requirements increase
Solution Approach 1:
The patent designs the inverter circuit to operate with voltage swing equal to that of the amplified signal from the rail-to-rail amplifier. This equipotential operation ensures that both circuits experience identical voltage variations, enabling them to operate in synchronization at high speeds. The matching voltage swings simplify the timing and phase relationships, reducing the practical precision requirements despite the theoretical constraints.
Data Source
AI summary
An input receiver includes a first current source circuit, a second current source circuit, a first rail-to-rail amplifier circuit, a first inverter circuit, and a second inverter circuit. The first current source circuit adjusts an operating current flowing through a first node according to a first bias signal. The second current source circuit adjusts a ground current flowing through a second node according to a second bias signal. The first rail-to-rail amplifier circuit and the first inverter circuit are connected in parallel between the first node and the second node. The first rail-to-rail amplifier circuit receives an input signal and compares the input signal with a reference voltage and accordingly outputs an amplified signal. The second inverter circuit is coupled between an operating voltage and a ground voltage. The second inverter circuit generates an output signal according to an inverted signal outputted by the first inverter circuit.