Patents Assigned to Vantis Corporation
  • Patent number: 6064595
    Abstract: A method of creating a reverse breakdown condition in an array of memory cells arranged in columns and rows in the array, and an array structure are provided. The method comprises the steps of applying a first voltage on a first column connection coupling a first column of said cells, and a second voltage on a second column connection coupling a second column of said cells; and applying a third voltage on a first row connection coupling a first row of said cells, and applying said second voltage on a second row connection coupling a second row of said cells. In this aspect, the difference between the first voltage and the third voltage creates said reverse breakdown condition in at least one cell occupying said first column and first row. In a further aspect, each cell includes a floating gate and the method of the invention includes the step of programming one of said cells by coupling a control voltage to each floating gate.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: May 16, 2000
    Assignee: Vantis Corporation
    Inventors: Stewart G. Logie, Sunil D. Mehta, Steven J. Fong
  • Patent number: 6064105
    Abstract: A shallow trench isolation structure and a method for forming the same for use with non-volatile memory devices is provided so as to maintain sufficient data retention thereof. An epitaxial layer is formed on a top surface of a semiconductor substrate. A barrier oxide layer is formed on a top surface of the epitaxial layer. A nitride layer is deposited on a top surface of the barrier oxide layer. Trenches are formed through the epitaxial layer and the barrier oxide layer to a depth greater than 4000 .ANG. below the surface of the epitaxial layer so as to create isolation regions in order to electrically isolate active regions in the epitaxial layer. A liner oxide is formed on sidewalls and bottom of the trenches to a thickness between 750 .ANG. to 1500 .ANG.. As a result, leakage current in the sidewalls are prevented due to less thinning of the liner oxide layer by subsequent fabrication process steps.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: May 16, 2000
    Assignee: Vantis Corporation
    Inventors: Xiao-Yu Li, Radu Barsan, Sunil D. Mehta
  • Patent number: 6043969
    Abstract: Electrostatic discharge (ESD) protection is provided for NMOS pull up transistors 700A-H and 702A-H of a 5.0 volt compatible output buffer using 2.5 volt process transistors. The ESD protection includes ballast resistors 701A-H and 703A-H separating individual pairs of NMOS pull up transistors 700A-H and 702A-H from the pad and from a power supply connection NV3. The ballast resistors enable turn on of additional pairs of NMOS pull up transistors after a first pair, such as 700A,702A turns on during an ESD event to prevent secondary breakdown in the first NMOS pair. Pairs of NMOS pull up transistors are used to prevent voltages across individual NMOS transistors from exceeding a 2.7 volt maximum while still enabling the transistors to provide 5.0 volts to the pad.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: March 28, 2000
    Assignee: Vantis Corporation
    Inventor: Bradley A. Sharpe-Geisler
  • Patent number: 6034893
    Abstract: A non-volatile memory cell includes a well region formed in a semiconductor substrate. First and second avalanche injection elements reside in the well region. A bifurcated floating-gate electrode includes a first segment overlying the first avalanche injection element and a second segment overlying the second avalanche injection element. A first contact region resides in the well region adjacent to the first segment of the floating-gate electrode, and a second contact region resides in the well region adjacent to the second segment of the floating-gate electrode. Upon the application of programming or erasing voltage, electrical charge is independently transferred to each of the first and second segments of the floating-gate electrode from the first and second avalanche injection elements, respectively.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: March 7, 2000
    Assignee: Vantis Corporation
    Inventor: Sunil D. Mehta
  • Patent number: 6031365
    Abstract: A band gap reference includes an operational amplifier with an output (n23) driving the gate of three current source transistors (501-503). The first current source (501) drives the (+) opamp input (n20) and a transistor (511) functioning as a diode. The second current source (502) drives the (-) opamp input and a series resistor (R.sub.1) and a transistor (512) functioning as a diode. The third current source (503) drives a series resistor (R.sub.2) and diode connected transistor (513). The opamp includes first series transistors (521) and (524) connected between V.sub.DD and V.sub.SS, and second series transistors (522) and (525) connected between V.sub.DD and V.sub.SS. With only two series transistors between V.sub.DD and V.sub.SS at any point, only two times a CMOS transistor threshold drop (less than 1.8 volts) will occur enabling V.sub.DD to range from 1.8-3.6 volts without altering the band gap reference output voltage (V.sub.DIODE). Further, CMOS transistors in the circuit may operate with a 2.
    Type: Grant
    Filed: March 26, 1999
    Date of Patent: February 29, 2000
    Assignee: Vantis Corporation
    Inventor: Bradley A. Sharpe-Geisler
  • Patent number: 6028789
    Abstract: A zero-power non-volatile memory cell includes a control element, an avalanche injection element, and a CMOS inverter. A floating-gate electrode is capacitively coupled to the control element, the avalanche injection element, and to the CMOS inverter. The avalanche injection element is arranged, so as to transfer electrical charge onto the floating-gate electrode. The presence of stored data within the memory cell is indicated by reading a supply voltage V.sub.DD at an output terminal of the inverter. Accordingly, data can be read from the non-volatile memory cell without applying electrical power to the cell.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: February 22, 2000
    Assignee: Vantis Corporation
    Inventors: Sunil D. Mehta, Brad Sharpe-Geisler, Steven Fong
  • Patent number: 6028758
    Abstract: An electrostatic discharge (ESD) protection circuit is provided for a 5.0 volt compatible I/O buffer with transistors made using a 2.5 volt process. The ESD circuit includes a lateral NPN bipolar junction transistor (BJT) 750 which provides a path to ground during ESD without experiencing gate oxide damage, since BJTs do not have a gate oxide as do CMOS transistors. The lateral NPN BJT is formed in a p- epitaxial layer of a p type substrate. The lateral NPN BJT functions to turn on during ESD due to charge up of the p- epitaxial region. The ESD protection circuitry further includes circuitry 722, 724, and 725-727 to clamp the pad voltage to a maximum value during an ESD event to prevent damage to the gate oxide of the 2.5 volt process CMOS transistors. The ESD protection circuit further includes stacked NMOS transistors 700A-H and 702A-H coupled by ballast resistors 701A-H and 703A-H between a power supply pin voltage and the pad.
    Type: Grant
    Filed: July 13, 1998
    Date of Patent: February 22, 2000
    Assignee: Vantis Corporation
    Inventor: Bradley A. Sharpe-Geisler
  • Patent number: 5999449
    Abstract: A two transistor EEPROM cell is described that is programmed and erased by electron tunneling across a tunneling channel in a P-well. The EEPROM cell has two transistors formed in a semiconductor substrate. The two transistors are a tunneling transistor (NMOS) and a read transistor (NMOS).
    Type: Grant
    Filed: January 27, 1999
    Date of Patent: December 7, 1999
    Assignee: Vantis Corporation
    Inventors: Sunil D. Mehta, Xiao-Yu Li
  • Patent number: 5990702
    Abstract: A Field Programmable Gate Array (FPGA) device includes a plurality of input/output blocks (IOBs) and variable grain blocks (VGBs). An inter-connect network provides routing of signals between the IOBs and VGBs. The VGBs include a plurality of L-organized CBBs (configurable logic blocks) having function-producing resources. The IOBs are arranged along a top, left, bottom and right side of the plurality of VGBs. An IOB includes a 1) delay for timing input signals, 2) a configurable output latch which may be set or reset responsive to control signals, and 3) transistor for controlling a NOR line. The IOB is programmably configured to the inter-connect network which includes vertical and horizontal inter-connect channels comprising adjacent inter-connect lines. The IOB inputs are connected to adjacent inter-connect lines including 1) direct connect input lines from adjacent super-VGBs, 2) MaxL lines, and 3) dendrite lines from adjacent dendrites.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: November 23, 1999
    Assignee: Vantis Corporation
    Inventors: Om P. Agrawal, Bradley A. Sharpe-Geisler, Giap H. Tran
  • Patent number: 5982193
    Abstract: A Field Programmable Gate Array (FPGA) device includes a plurality of input/output blocks (IOBs) and variable grain blocks (VGBs). An inter-connect network provides routing of signals between the IOBs and VGBs. The VGBs include a plurality of L-organized CBBs (configurable logic blocks) having function-producing resources. The IOBs are arranged along a top, left, bottom and right side of the plurality of VGBs. An IOB includes a 1) delay for timing input signals, 2) a configurable output latch which may be set or reset responsive to control signals, and 3) transistor for controlling a NOR line. The IOB is programmably configured to the inter-connect network which includes vertical and horizontal inter-connect channels comprising adjacent inter-connect lines. The IOB inputs are connected to adjacent inter-connect lines including 1) direct connect input lines from adjacent super-VGBs, 2) MaxL lines, and 3) dendrite lines from adjacent dendrites.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: November 9, 1999
    Assignee: Vantis Corporation
    Inventors: Om P. Agrawal, Bradley A. Sharpe-Geisler, John D. Tobey, Giap H. Tran
  • Patent number: 5969992
    Abstract: An EEPROM cell is described that is programmed and erased by electron tunneling across an entire portion of separate transistor channels. The EEPROM cell has three transistors formed in a P-well of a semiconductor substrate. The three transistors are a tunneling transistor (NMOS), a sense transistor (NMOS) and a read transistor (NMOS). Electron tunneling occurs to program the EEPROM cell through a sense tunnel oxide layer upon incurrence of a sufficient voltage potential between a floating gate and the sense channel. Electron tunneling also occurs to erase the EEPROM cell through a tunnel oxide layer upon incurrence of a sufficient voltage potential between the floating gate and the tunneling channel.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: October 19, 1999
    Assignee: Vantis Corporation
    Inventors: Sunil D. Mehta, Xiao-Yu Li
  • Patent number: 5912550
    Abstract: A power converter provides a voltage reference (Vdd) to a plurality of transistors on an integrated circuit with a limited voltage swing when a load is connected and removed. The power converter includes an opamp (100) having an input (+) receiving a voltage reference (V.sub.DIOD), an input (-) connected to a resistor divider (102, 104) and an output driving the gate of a transistor (110). The transistor (110) has a source to drain path providing a 3.3 volt supply (NV3EXT) to an output node (n2) which supplies Vdd. The output node (n2) is connected back to the resistor divider (102,104) and to the source of a cascode transistor (300). The cascode (300) is connected with cascode (302) to form a current mirror which is interconnected with transistor (304) and capacitor (306) to slow the response at node (n7) to transitions at the output node (n2). Cascode (300) drives a current mirror (314, 316).
    Type: Grant
    Filed: November 19, 1998
    Date of Patent: June 15, 1999
    Assignee: Vantis Corporation
    Inventor: Bradley A. Sharpe-Geisler