Linearized transconductance cell
Granted: December 11, 2001
Patent Number:
6329865
A transconductance cell has first and second transistors, each transistor having a control terminal and first and second terminals. A signal is output from the second transistor in response to a voltage input applied to the control terminal of the first transistor. The transconductance cell includes a linear element coupled between the first terminal of the first transistor and the first terminal of the second transistor. A tank circuit is coupled between a reference potential and a node…
Circuit for compensating curvature and temperature function of a bipolar transistor
Granted: December 11, 2001
Patent Number:
6329868
Curvature in the temperature response of junction voltage of a diode or transistor is compensated by circuitry which offsets the curvature at temperatures below a reference temperature and at temperatures above a reference temperature. Two current sources are provided including a first current source of current proportional to absolute temperature (PTAT) less a current complimentary to absolute temperature (CTAT) and a second current source of PTAT plus beta times CTAT…
Method and apparatus for improving power supply rejection in amplifier rail to rail output stages
Granted: December 11, 2001
Patent Number:
6329878
Apparatus and methods to provide high supply rejection and rail-to-rail output swing at the output of an amplifier circuit. A power source supplies power to a low noise regulator and to a differential amplifier output stage. The low noise regulator supplies power to an input stage that is coupled to the output stage, and also provides a reference to the output stage for power supply noise reduction purposes. This configuration of first and second circuits give the output both full…
Sample and hold circuits and methods
Granted: December 11, 2001
Patent Number:
6329848
Sample and hold circuits and methods to reduce distortion. A signal to be sampled is connected across a capacitor through a field effect device, which field effect device is turned off when the sample voltage across the capacitor is to be held. When the field effect device coupling the sample voltage to the capacitor is turned on, the body and gate voltages of the field effect device are made to have a fixed voltage relative to the voltage being sampled, so that the characteristics of…
Enhanced LC filter with tunable Q
Granted: October 23, 2001
Patent Number:
6307442
A tunable electronic filter circuit is provided including an input terminal and an output terminal connected to the input terminal with a node therebetween. An inductor, a variable capacitor, and a variable resistor are connected between the node and ground. Coupled to the variable capacitor and the variable resistor is a feedback control circuit. The feedback control circuit is operable to tune the variable capacitor in order to set a predetermined frequency, or center frequency, of the…
Method of forming a shallow and deep trench isolation (SDTI) suitable for silicon on insulator (SOI) substrates
Granted: October 16, 2001
Patent Number:
6303413
A method of forming a shallow-deep trench isolation (SDTI) is provided that includes the steps of forming a pair of deep trenches through a silicon on insulator (SOI) layer without substantially disturbing an underlying buried oxide (BOX) layer. Once the deep trenches are formed, the trenches are filed with suitable electrical isolating materials, such as undoped poly-silicon or dielectric material, and etched back to obtain a substantially planarized top surface. Subsequently, an active…
Method and apparatus for deglitching digital to analog converters
Granted: October 16, 2001
Patent Number:
6304199
Asynchronous and synchronous deglitch controllers controlling switches of sample and hold circuits for deglitching digital to analog converters. Asynchronous and synchronous deglitch controllers detect transitions in the state of the digital input code to trigger or allow a one shot pulse to cause sample and hold circuits to go into hold mode for the period of the one shot pulse. Secondary glitch cancellation circuitry models the environment of the sample and hold circuit to emulate…
Method and apparatus for cascaded ground return amplifier
Granted: October 9, 2001
Patent Number:
6300827
A cascaded amplifier is integrated within an integrated circuit with a cascaded ground bus. The cascaded ground bus provides two ground points at opposite ends. Each amplifier ground of each amplifier stage couples to the ground wire there between. The cascaded ground bus substantially reduces the parasitic inductance in the emitter leg of each IC transistor within each amplifier. The lay out of the cascaded ground bus wire is tightly coupled to the lay out of the input wires so that…
Single wire bus interface for multidrop applications
Granted: October 2, 2001
Patent Number:
6298066
The present invention enables data communications between multiple devices over a single wire bus. This single-wire interface can be used for sensors, amplifiers, analog-to-digital converters (ADCs), or any other circuit which would normally have an electrical output. Advantages of the present invention include a reduction in device pin count, conservation of the limited number of I/O pins on the control device, and reduced board layout complexity. Speaking generally, each slave device…
Boosting circuit with supply-dependent gain
Granted: August 7, 2001
Patent Number:
6271715
The present invention comprises a method and apparatus for boosting an input signal to an output signal with a variable gain according to a supply voltage. The circuit comprises a detector and a voltage booster. The detector detects the supply voltage and generates a control signal having a value dependent on a difference between the detected supply voltage and a critical supply voltage. The critical supply voltage is temperature insensitive. The voltage booster is coupled to the…
Semiconductor devices with improved lead frame structures
Granted: July 24, 2001
Patent Number:
6265761
A lead frame to support a semiconductor die within an encapsulating package. The lead frame includes a first rail and a second rail in a first plane, with the second rail parallel to and spaced apart from the first rail by more than the length of the package. A first bar and a second bar are connected perpendicularly to the first and second rails, with the second bar spaced apart from the first bar by more than the width of the package. A lead is connected perpendicularly to the first…
Method and apparatus for switching low voltage CMOS switches in high voltage digital to analog converters
Granted: July 24, 2001
Patent Number:
6266001
A varying power supply range, that can exceed the breakdown voltage of switches within a DAC, is used to generate positive and negative generated OFF voltages substantially fixed and less than the breakdown voltage to accommodate a wide range of analog reference voltages and power supply voltages. The digital input signal having digital input levels is received by a TTL/CMOS input receiver and level shifted to logic levels having the positive and negative generate voltage levels. A…
Rigid encapsulation package for semiconductor devices
Granted: July 3, 2001
Patent Number:
6255728
A rigid encapsulation package for semiconductor sensors, actuators, and devices is described. In one embodiment, a semiconductor pressure sensor includes a sensor element having a deformable diaphragm for measurement of pressure, and a cap that includes a recess. The cap is attached to the sensor element to form a cavity therebetween. The pressure sensor further includes a leadframe, interconnecting bond wires, a pressure port that is coupled to the sensor element, and a nominally rigid…
Communication circuit having network connection detection capability
Granted: May 15, 2001
Patent Number:
6233689
Methods and apparatus for providing network communications capability to a computer system in accordance with standard communication line protocols are described, including interface circuits which sense various characteristics of the communication lines to control or provide signals to control power to line drivers and/or other substantial power consuming circuitry to conserve power when communication line conditions indicate powering such circuits is not useful. Various embodiments are…
Compensated semiconductor pressure sensor
Granted: May 8, 2001
Patent Number:
6229190
A semiconductor pressure sensor compatible with fluid and gaseous media applications is described. The semiconductor pressure sensor includes a sensor capsule having a semiconductor die and a silicon cap that is bonded to the semiconductor die. The semiconductor die includes a diaphragm that incorporates piezoresistive sensors thereon, and a stress isolation mechanism for isolating the diaphragm from packaging and mounting stresses. The silicon cap includes a cavity for allowing the…
Method and apparatus for digital to analog converters with improved switched R-2R ladders
Granted: April 24, 2001
Patent Number:
6222473
Operating range of R-2R ladders for digital to analog converters (DACs) is improved by increasing resistance in series with a termination switch in a termination leg to avoid transistor saturation for increasing DAC resolution, increasing reference voltage range, or other application. The switched R-2R ladder circuit is modified to compensate for increasing resistance to maintain proper resistor matching for generation of the appropriate range of analog output voltages for a digital…
Efficient error correction in pipelined analog-to-digital converters
Granted: April 3, 2001
Patent Number:
6211806
The present invention discloses a method and apparatus for correcting errors in N digital word generated by N+1 pipelined analog-to-digital converters. The method comprises the steps of: (1) synchronizing the N digital words by N groups of pipeline registers; and (2) correcting the synchronized N digital words by performing either an incrementing operation or a decrementing operation based on an adjustment value.
Merged variable gain mixers
Granted: April 3, 2001
Patent Number:
6212369
The present invention teaches parallel coupling what are herein termed a “switching stage” and a “steering stage,” thereby arranging the mixer and variable gain amplifier circuitry as a single merged circuit. The merged variable gain mixers of the present invention provide mixing and gain functionality utilizing only that power needed for a basic mixer function and only the transconductance of the basic mixer function (thereby eliminating non-linearities…
Methods and apparatus to predictably change the output voltage of regulators
Granted: March 27, 2001
Patent Number:
6208127
Programmable voltage regulators that change from a first set-point voltage to a second set-point voltage at a controlled rate. The set-point signal is a multi-bit set-point signal with the rate of change in the regulator output between set-points being predetermined or externally controllable. Various embodiments are disclosed.
Current mode charge pumps
Granted: March 27, 2001
Patent Number:
6208196
Current mode charge pumps having improved power consumption characteristics and reduced peak current requirements. The current mode charge pumps utilize a differential transistor pair with a current source providing the tail current for the differential pair. The differential pair alternately steers the current of the current source through first and second fly capacitors, with additional circuitry coupling the opposite fly capacitor, previously charged, to the output of the charge pump.…
