NMOS Line Driver Circuit With Reduced Swing for Lower Transmission Power
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Solution Overview
Problem
Existing line driving circuits in semiconductor devices consume high power due to signals swinging fully between VDD and ground voltage, leading to increased power consumption in transmission lines.
Innovation Solution
A line driving circuit comprising NMOS transistors and a differential amplification unit generates output signals with reduced swing width, reducing power consumption by using NMOS transistors as pull-up and pull-down drivers, and a receiver converts reduced swing signals to full swing signals for interior circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a typical CMOS-type inverter driver is used as a line driving circuit, then the signal can be transmitted through the transmission line, but the power consumption required in the transmission line increases due to the signal swinging fully between VDD and ground voltage
Solution Approach 1:
The patent changes the voltage swing parameter of the transmission signal from full swing (VDD to ground) to reduced swing (VDD/2 to ground or similar). This is achieved by using a differential amplifier to generate complementary output signals with controlled voltage levels, thereby reducing the power consumption in the transmission line while maintaining signal transmission capability.
Solution Approach 2:
The patent introduces a differential amplification unit as an intermediary between the data signal source and the transmission line. This unit generates complementary output signals (first and second output signals) that drive the NMOS transistors, enabling reduced swing transmission while preserving the ability to transmit data through the transmission line.
2Use of energy by moving object
If the signal swing width is reduced to lower power consumption, then power consumption decreases, but the signal level corresponding to logic states may become less distinct
Solution Approach 1:
The differential amplification unit acts as an intermediary that receives data signals and generates complementary output signals with controlled voltage levels. This mediator ensures that even with reduced swing width, the signal levels remain distinct and properly differentiated for logic states, maintaining measurement precision while reducing power consumption.
Solution Approach 2:
The patent carefully controls the voltage level parameters of the output signals from the differential amplifier. By setting the voltage levels to correspond to VDD or ground voltage for the complementary signals, the patent maintains sufficient distinction between logic states while achieving reduced power consumption through smaller swing width in the actual transmission line signal.
Data Source
AI summary
Disclosed is a line driving circuit which includes two NMOS transistors in series between a supply voltage and a ground voltage. The output of the line driving circuit is applied to an interior circuit through a transmission line, and a repeater is used when the transmission line is long.