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Patent Issued for Negative Voltage Regulation Circuit and Voltage Generation Circuit Including the Same

September 3, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Alexandria, Virginia, VerticalNews journalists report that a patent by the inventor Kwon, Jae-Kwan (Gyeonggi-do, KR), filed on March 14, 2013, was published online on August 19, 2014.

The patent's assignee for patent number 8810306 is SK Hynix Inc. (Gyeonggi-do, KR).

News editors obtained the following quote from the background information supplied by the inventors: "Exemplary embodiments of the present invention relate to semiconductor design technology, and more particularly, to a negative voltage regulation circuit and a voltage generation circuit including the same.

"Semiconductor devices operate internal circuits thereof using external voltages supplied from the external source. However, since various levels of voltages are used in a semiconductor device, it may be difficult to supply all of the voltages to be used in the semiconductor device from the external source. In this regard, a semiconductor device includes voltage generation circuits for generating voltages with various levels using the external voltages.

"FIG. 1 is a block diagram illustrating a conventional voltage generation circuit for generating a read voltage supplied to a word line in a read operation in a nonvolatile memory device such as a flash memory.

"Referring to FIG. 1, the voltage generation circuit includes a first correction unit 110, a second correction unit 120, a target value provision unit 130, and an adding unit 140.

"The first correction unit 110 generates a voltage X for regulating the level of the read voltage VREAD which is a final output voltage of the voltage generation circuit, based on a process skew variation. That is, the level of the voltage X is changed based on the process skew variation.

"The second correction unit 120 for correcting a temperature variation generates a voltage Y based on the voltage X and temperature information (not illustrated) outputted from a temperature sensor (not illustrated). That is, the level of the voltage Y is changed based on the level of the voltage X and the temperature information. Thus, the voltage Y includes information on the amount of the read voltage VREAD to be regulated based on the process skew variation and the temperature variation.

"The target value provision unit 130 generates a voltage Z having information on a target voltage of the read voltage VREAD. The target voltage indicates a voltage level of the read voltage VREAD in a state in which the process skew variation and the temperature variation are normal. For example, when the target voltage is 2V, the read voltage VREAD becomes 2.+-..alpha.V based on the process skew variation and the temperature variation (.alpha. is a correction value corresponding to the process skew variation and the temperature variation). When the target voltage is 3V, the read voltage VREAD becomes 3.+-..alpha.V based on the process skew variation and the temperature variation.

"The adding unit 140 linearly adds the voltage Y and the voltage Z to generate the read voltage VREAD. Since the voltage Y includes information on a correction value of the read voltage VREAD based on the temperature variation and the process skew variation and the voltage Z includes information on the target voltage of the read voltage VREAD, the read voltage VREAD generated by linearly adding the voltage Y and the voltage Z has a value of `target voltage.+-..alpha.`.

"In the conventional art, only a positive voltage is used as the read voltage VREAD. Recently, a negative voltage is also used as the read voltage to secure cell Vt distribution. However, it may be difficult to design the adding unit 140 that adds a negative voltage (e.g., the target voltage) and a positive voltage (e.g., the correction value of the target voltage) or adds two negative voltages. Since the adding unit 140 uses the negative voltage as a driving voltage even when implemented, a large amount of current may be consumed. In this regard, a voltage generation circuit that may regulate the level of a negative voltage by positive voltages while providing the negative voltage as a final output voltage is in demand."

As a supplement to the background information on this patent, VerticalNews correspondents also obtained the inventor's summary information for this patent: "Exemplary embodiments of the present invention are directed to a negative voltage regulation circuit that may regulate the level of a negative voltage based on a positive voltage.

"Other embodiments of the present invention are directed to a voltage generation circuit that may generate various types of trimming information, such as process skew variation or temperature variation, as a positive voltage, and may generate a negative voltage having a level varying by the positive voltage including the trimming information.

"In accordance with an embodiment of the present invention, a negative voltage regulation circuit includes an operational amplifier configured to receive a feedback voltage and an input voltage, a pull-up element configured to pull-up drive a first node based on output voltage of the operational amplifier, a load element coupled between the first node and a negative voltage terminal, a pull-down element configured to pull-down drive a final negative voltage output terminal using a voltage of the negative voltage terminal, based on a voltage level of the first node, and a voltage division unit coupled between the output terminal and a pull-up voltage terminal, and configured to generate the feedback voltage by voltage division.

"In accordance with another embodiment of the present invention, a voltage generation circuit includes a negative voltage generation unit configured to generate a negative voltage, a first voltage generation unit configured to generate a first positive voltage having first correction information, a second voltage generation unit configured to generate a second positive voltage having second correction information, an addition unit configured to add the first positive voltage and the second positive voltage to generate a third positive voltage, and a negative voltage regulation unit configured to regulate the negative voltage based on the third positive voltage and regulation target information, and to generate a final negative voltage.

"In accordance with yet another embodiment of the present invention, a negative voltage regulation circuit includes an operational amplifier configured to receive a feedback voltage and an input voltage, a first PMOS transistor having a source coupled to a power supply voltage terminal, a drain coupled to a first node, and a gate receiving an output voltage of the operational amplifier, a first resistor coupled between the first node and a negative voltage terminal, a voltage division unit coupled between the power supply voltage terminal and a final output terminal, and configured to output the feedback voltage by using a voltage division ratio, which is varied based on regulation target information, and a second PMOS transistor having a source coupled to the final output terminal, a drain coupled to the negative voltage terminal, and a gate coupled to the first node.

"The negative voltage regulation circuit in accordance with an embodiment of the present invention may regulate the level of a negative voltage based on a positive voltage with a simple circuit configuration.

"The voltage generation circuit in accordance with another embodiment of the present invention may generate various types of trimming information, such as process skew variation or temperature variation, as a positive voltage, and may generate a negative voltage having a level varying based on the positive voltage including the trimming information."

For additional information on this patent, see: Kwon, Jae-Kwan. Negative Voltage Regulation Circuit and Voltage Generation Circuit Including the Same. U.S. Patent Number 8810306, filed March 14, 2013, and published online on August 19, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8810306.PN.&OS=PN/8810306RS=PN/8810306

Keywords for this news article include: Electronics, SK Hynix Inc., Semiconductor.

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Source: Electronics Newsweekly


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