Enhanced linearity, low switching perturbation resistor string matrices
Granted: January 14, 2003
Patent Number:
6507272
Enhanced linearity, low switching perturbation resistor string matrices. The resistor strings are arranged in an array of a plurality of rows of resistive elements and electrically arranged with rows equally spaced above and below the physical centerline of the array being coupled together in an opposite sense. Preferably also physically adjacent rows are equally spaced from the center of the electrical order of rows. This connection prevents accumulation of errors due to vertical and…
Universal serial bus powered battery charger
Granted: January 14, 2003
Patent Number:
6507172
Universal serial bus powered battery charger primarily intended for use in battery powered hand-held and other portable devices to charge the battery or batteries within the battery powered device when the same is connected to a host device, powered hub or a bus powered hub through a universal serial bus (USB) port. The battery charger includes one or more current limits to conform to the universal serial bus current supply limit set in the USB specification. Any of the universal serial…
Fully programmable multimodulus prescaler
Granted: December 31, 2002
Patent Number:
6501816
The present invention is a method and system for a fully programmable modulus pre-scaler. In one embodiment, the pre-scaler is a cascade of fully programmable divide-by-⅔ sections. A fully programmable divide-by-⅔ section includes a state machine and a control circuit. The state machine generates a modulus control output synchronously with a clock signal in response to a modulus control input and a programming signal. The state machine has a plurality of states…
Method of forming high density EEPROM cell
Granted: December 24, 2002
Patent Number:
6498084
A memory cell formed on a substrate with a well having drain and source regions and a channel therebetween, a control gate with a first portion overlying a first region of the channel proximate the drain region and a second portion overlying a second region of the channel proximate the source region, and a floating gate with a first portion overlying the first control gate portion, a second portion overlying a third region of the channel between the first and second regions, and a third…
Method of forming an NPN device
Granted: December 10, 2002
Patent Number:
6492237
A method of forming an NPN semiconductor device includes the steps of forming a collector region within a substrate, forming a base region over the collector region, and forming an oxide-nitride-oxide stack over the base region. Once these three structures are formed, an opening is created through the oxide-nitride-oxide stack to expose the top surface of the base region. Then, a doped polysilicon material is used to fill the opening and make electrical contact to the base region. The…
Low voltage CMOS analog switch
Granted: December 10, 2002
Patent Number:
6492860
A low voltage analog switch having low leakage off-current and including a first transmission gate having a first N-channel transistor and a first P-channel transistor, each first and second transistor having respective drain and source terminals coupled together to form switch drain and source terminals, and a second transmission gate having a second N-channel transistor coupled in series to a second P-channel transistor coupled in series to a third N-channel transistor, the second…
Method of forming an integrated circuit on a low loss substrate
Granted: December 3, 2002
Patent Number:
6489217
A method for manufacturing an integrated circuit structure is disclosed. The method includes providing a layer of porous silicon, and epitaxially growing a high resistivity layer on the layer of porous silicon. Devices are then formed on the high resistivity layer to produce the integrated circuit structure. The integrated circuit structure is attached to a silica substrate, such that the silica substrate is coupled to the devices. Further, surface contacts are provided on the structure.…
Linear and multi-sin h transconductance circuits
Granted: December 3, 2002
Patent Number:
6489848
The present invention teaches a variety of transconductance circuits formed having two or more class AB transconductor amplifiers coupled in parallel. The class AB transconductor amplifiers have non-linear voltage to current transfer functions and are each designed with an offset chosen such that the combination of the individual nonlinear transfer functions achieve a more linear transconductance circuit.
Segmented resistor string digital-to-analog converters
Granted: November 26, 2002
Patent Number:
6486818
Segmented resistor string digital-to-analog converters using a resistor string primary converter segment and a current source secondary. The primary converter segment provides conversion of the most significant bits to an analog voltage form and the current source provides conversion of the least significant bits to an analog current form. An output circuit combines the two into a single analog output. Various embodiments are disclosed.
Method of low-selective etching of dissimilar materials having interfaces at non-perpendicular angles to the etch propagation direction
Granted: November 12, 2002
Patent Number:
6479394
A method of etching dissimilar materials having interfaces at non-perpendicular angles to the direction of the etch propagation that results in a low selectivity etch in order to achieve an improved planarized etched surface. The method includes the step of subjecting the dissimilar materials to a process gas mixture that includes a first gas that dominates the etching of a first material and a second gas that dominates the etching of a second material. The flow rates for the first and…
Method of forming laser trimmable thin-film resistors in a fully planarized integrated circuit technology
Granted: November 5, 2002
Patent Number:
6475873
A new and improved method of forming a thin film resistor is provided herein that overcomes many of the drawbacks of prior art methods. More specifically, the new method of forming a thin film provides for a well-controlled dielectric thickness under the thin film resistor which is useful for laser trimming purpose. The preferred thickness of the dielectric layer is an integer of a quarter wavelength of the optical energy used to laser trim the resistor. The new method also provides…
High performance amplifier circuits using separate power supplies
Granted: November 5, 2002
Patent Number:
6476678
The present invention is an apparatus and method to provide a high supply rejection and a full rail-to-rail output swing in an amplifier circuit. A first stage generates a first output. The first stage is powered by a second supply. A second stage is coupled to the first stage to generate an amplifier output. The second stage is powered by a first supply. The first and second supplies are different in regulation mode. By making the second supply a low noise supply, the power supply noise…
Low voltage, fast settling precision current mirrors
Granted: October 29, 2002
Patent Number:
6472858
Low voltage, fast settling precision current mirrors and methods. The precision current mirror have first and second current mirrors, each having an input to be mirrored and a mirror output, the current mirrors being coupled so that the mirror output of each current mirror receives part of the input to be mirrored by the other current mirror, the first current mirror also mirroring current for re-mirroring to the input of the second current mirror, and to a precision current mirror…
Combining networks for switchable path power amplifiers
Granted: October 29, 2002
Patent Number:
6472935
The present invention teaches a power amplifier having two or more output power devices and a combining network for switching the output path between these several power devices. The first output power device is designed for power efficient signal amplification at the power amplifier's highest output power level. The second output power device is designed for power efficient signal amplification at the output power level that the power amplifier is most likely to operate. Either the…
Cold cathode fluorescent lamp controller
Granted: October 22, 2002
Patent Number:
6469454
A closed-loop control of the transformer voltage in a Royer inverter for cold cathode fluorescent lamps to provide a wide dimming range capability, such as by way of example, an approximately 100:1 dimming range. This dimming range is achieved by a combination of current control and pulse control to provide a much wider dimming range than can be achieved by using either form of control alone. Various additional features and capabilities of the invention are also described.
Differential output switching converter with ripple reduction
Granted: October 8, 2002
Patent Number:
6462520
A differential switching converter system is disclosed. The converter system includes a plurality of switching converters having at least first and second converters. The plurality of switching converters is coupled in a differential configuration across an output load. Each converter has at least first and second transistors configured to apply and receive energy to and from an energy storage element. The converter system also includes a controller, which is configured to control the…
Low noise bandgap voltage reference circuit
Granted: October 8, 2002
Patent Number:
6462526
A bandgap reference adds two bipolar transistors to the conventional bandgap voltage reference. One of these added transistors is Darlington configured with one of the two bipolar transistors used in a conventional bandgap reference, and the other added transistor is configured similarly with the other bipolar transistor used in a conventional bandgap voltage reference. The configuration is such that a portion of the currents that flow into the collector terminal of the two bipolar…
Ripple canceling, soft switching isolated DC/DC converters with reduced voltage stress synchronous rectification
Granted: September 3, 2002
Patent Number:
6445599
Ripple canceling, soft switching isolated DC/DC converters with reduced voltage stress synchronous rectification. The converters include interleaved switching converters providing power to a node supplying power to a zero volt switching bi-phase power conversion stage driving synchronous rectifiers feeding an output filter. In one embodiment, the interleaved converters are boost mode converters operating in continuous conduction mode boost converters. Various embodiments are disclosed.
Digital trim capacitor programming
Granted: August 27, 2002
Patent Number:
6441671
A programming method (250) for digitally programming the adjustment of an electronic trim capacitor (212, 314, 414). In an initial step (252), programming is initiated by setting an enable terminal (224). In subsequent steps (254, 256) a pulse signal (226) then applied to a program terminal (222) and the number of pulses (228) provided to the programming terminal (222) while the enable terminal (224) is set determines the total number of capacitance increments for which the electronic…
Phase failure detector for multi-phase switching regulators
Granted: August 13, 2002
Patent Number:
6433527
The present invention offers a low cost, reliable, on chip implementation that takes advantage of the nature of the average current mode topology to detect phase failures within a multi-phase system. The invention further includes sensing average current to the load, generating error voltages and changing duty cycles when the sensed load current is not at the desired level.
