Description:

 INV-17018

Background

In semiconductor memory devices, data signals transmitted along a transmission line are reflected at the end of the transmission line. These reflected data signals may degrade the quality of the transmitted data signals. In order to reduce the reflection of the data signals, a termination resistor is usually coupled to the end of the transmission line. The termination resistor reduces the reflection of the data signals by matching internal impedance with the external impedance of a memory system. Such a termination resistor may be used in a DRAM (Dynamic Random Access Memory) having a fast operation speed.

Recently, as the operation speeds of memory device have been increasing, impedance matching has become very important. Accordingly, in high speed data transmission, new impedance calibration methods providing high signal quality and stability are extremely valuable. Adding to that, the possibility to actively control the characteristics of an output driver of a semiconductor device in real time while minimizing power consumption is highly desirable.

Technology Overview

In this invention, the impedance calibration device developed by Northeastern University inventors is capable of actively controlling the characteristics of an output driver of a semiconductor device in real time.

This device includes a process sensor that detects a process condition for the semiconductor device and outputs a process signal, a temperature monitoring sensor that detects a temperature of the semiconductor device and outputs a temperature signal, a converter that converts the process signal and the temperature signal into a digital signal, and a code generation circuit that generates and outputs a driving code for controlling a level of a voltage at an output node according to the digital signal of the converter and a data signal. This device further includes an output driver that pulls up or pulls down the voltage at the output node according to the driving code in order to compensate for any change in process conditions or variations in temperature. 

Benefits

  • Real time adaptive and active control over output driver characteristics
  • Stable and high signal quality
  • Minimized power consumption

Applications

  • Semiconductors
  • High speed data transmission
  • Process control

 

Opportunity

  • License
  • Partnering
  • Research collaboration

Patents

Seeking

  • Commercial partner
  • Development partner
  • Licensing

IP Status

  • Patented

 

Patent Information:
For Information, Contact:
Dormant Physical
Northeastern University
 
Inventors:
Yong-Bin Kim
Hae Kang Jung
Keywords: