Abstract: A controllably switched arrangement selectively couples multiple circuit functions, such as reverse polarity detection, ring-trip and line voltage measurement, of a telecommunication card to the same external programming component (e.g., capacitor) on an as needed basis, by means of associated coupling circuits and a controlled switching circuit. The coupling circuits are controllably enabled/disabled in association with the particular circuit function required, while the controlled switching circuit selectively connects each coupling circuit with the external component. Through combined control of the coupling circuits and the switching circuit, respectively different circuit functions can be implemented with the same external component.

Abstract: A method for enhancing thermal performance of an integrated circuit package attaches a dummy die to the semiconductor die of the integrated circuit. The dummy die is then thermally coupled through external terminals to the conductive layers of a printed circuit board. In one embodiment, the integrated circuit package includes an insulating substrate on which the dummy die is attached. Conductive vias thermally connect conductive terminals provided on one side of the insulating substrate to conductive terminals provided on the other side of the insulating substrate. In one embodiment, the integrated circuit package is provided as a ball grid array (BGA) package. In addition, multiple layers of conductors can be provided in both the insulating substrate of the integrated circuit and in the external printed circuit board.

Abstract: A phase-locked loop having a programmable loop bandwidth is provided. A PLL comprises an oscillator operable to receive an error-correction signal and to generate an oscillator signal having a frequency that is related to the error-correction signal. The PLL further comprises a phase-frequency detector (PFD) coupled to the oscillator and operable to receive a reference signal and to generate the error-correction signal based upon a phase difference between the reference signal and a feedback signal derived from the oscillator signal. The PLL further comprises an error-correction signal suppression circuit coupled to the PFD and operable to control the loop bandwidth of the PLL by periodically enabling the PFD.

Abstract: A circuit arrangement prevents clipping of pulse metering (teletax) signals in a telephone line card channel that results from the differential impedance between a subscriber line interface circuit (SLIC) and the line at the frequency band of teletax signals. The circuit arrangement is configured to sense pulse metering signals through a delay circuit, which is coupled to a reflected signal cancellation circuit. The reflected signal cancellation circuit contains a transconductance amplifier circuit that generates a pair of complementary polarity output currents representative of the sensed teletax signal. One of these output currents is fed back to a programmed impedance element in the transmission channel path of the SLIC so as to effectively cancel the reflected teletax signal.

Abstract: A subscriber line interface circuit (SLIC) drive arrangement controllably adjusts DC biasing and overhead voltage characteristics for wireline pair that is optimized for each mode of operation of the SLIC. Respective tip and ring DC drive voltages supplied by tip and ring drive amplifiers are controlled so that the differential DC voltage across the wireline pair has a first constant value during on-hook mode, in which DC loop current may vary between zero and a first DC loop current threshold value associated with a transition from on-hook mode toward off-hook mode. During a transition between on-hook mode and off-hook mode, the tip and ring DC drive voltages are controlled so as to vary the differential DC drive voltage in proportion to monitored DC loop current. During off-hook mode, the differential DC voltage is set at a second fixed value. If an upper DC loop current threshold is reached during off-hook mode, the differential DC voltage is sharply reduced from its second constant value.

Abstract: A silicon semiconductor die comprises a heavily doped silicon substrate and an upper layer comprising doped silicon of a first conduction type disposed on the substrate. The upper layer comprises a well region of a second, opposite conduction type adjacent an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon. Both the well region and adjacent edge termination zone are disposed at an upper surface of the upper layer, and an oxide layer overlies the upper layer and the edge termination zone. A process for forming a silicon die having improved edge termination. The process comprises forming an upper layer comprising doped silicon of a first conduction type on a heavily doped silicon substrate, and forming an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon at an upper surface of the upper layer.

Abstract: A low temperature coefficient resistor(TCRL) has some unrepaired ion implant damage. The damaged portion raises the resistance and renders the resistor less sensitive to operating temperature fluctuations. A polysilicon thin film low temperature coefficient resistor and a method for the resistor's fabrication overcomes the coefficient of resistance problem of the prior art, while at the same time eliminating steps from the BiCMOS fabrication process, optimizing bipolar design tradeoffs, and improving passive device isolation. A low temperature coefficient of resistance resistor (TCRL) is formed on a layer of insulation, typically silicon dioxide or silicon nitride, the layer comprising polysilicon having a relatively high concentration of dopants of one or more species. An annealing process is used for the implanted resistor which is shorter than that for typical prior art implanted resistors, leaving some intentional unannealed damage in the resistor.

Abstract: A method for enhancing thermal performance of an integrated circuit package attaches a dummy die to the semiconductor die of the integrated circuit. The dummy die is then thermally coupled through external terminals to the conductive layers of a printed circuit board. In one embodiment, the integrated circuit package includes an insulating substrate on which the dummy die is attached. Conductive vias thermally connect conductive terminals provided on one side of the insulating substrate to conductive terminals provided on the other side of the insulating substrate. In one embodiment, the integrated circuit package is provided as a ball grid array (BGA) package. In addition, multiple layers of conductors can be provided in both the insulating substrate of the integrated circuit and in the external printed circuit board.

Abstract: A switched current steering device includes a switch activation unit coupled to a set of actual switches and an associated set of dummy switches. Based upon current actual switch states, next actual switch states as specified by a data stream, and current dummy switch states, the switch activation unit selectively generates dummy signals that indicate or specify next dummy switch states. The switch activation unit generates the dummy signals such that the total number of actual switches and dummy switches experiencing state transitions remains constant from one switching cycle to another.

Abstract: A full-duplex radio transceiver includes a transmitter and a receiver. A duplexer is connected to an output of the transmitter and an input of the receiver. The receiver includes a low noise amplifier having a nonlinear portion capable of generating undesired cross-modulation signals based upon a portion of the transmit signal coupled thereto from the duplexer and a signal from another adjacent transmitter. A bandpass filter is connected to an output of the low noise amplifier, and at least one downconverter stage is connected to an output of the bandpass filter. A reactive termination circuit is connected between the low noise amplifier and the bandpass filter for changing an impedance presented to the output of the low noise amplifier with respect to signals from the colocated transmitter to thereby reduce undesired cross-modulation signals.

Abstract: If adequate setup time or hold time cannot be provided between a recording clock signal and modulated signal during the use of a laser control integrated circuit for generating a recording strategy from the recording clock signal and modulated signal to drive a laser diode, the disk recording information becomes erroneous. To solve this problem, the present invention provides the laser control integrated circuit input stage for the recording clock signal and modulated signal with variable delay devices that can vary the phases of these signals. The variable delay devices control the delay amounts of the variable delay devices in accordance with disk recording information error and optimize the phase relationship between the recording clock signal and modulated signal.

Abstract: A silicon semiconductor die comprises a heavily doped silicon substrate and an upper layer comprising doped silicon of a first conduction type disposed on the substrate. The upper layer comprises a well region of a second, opposite conduction type adjacent an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon. Both the well region and adjacent edge termination zone are disposed at an upper surface of the upper layer, and an oxide layer overlies the upper layer and the edge termination zone. A process for forming a silicon die having improved edge termination. The process comprises forming an upper layer comprising doped silicon of a first conduction type on a heavily doped silicon substrate, and forming an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon at an upper surface of the upper layer.

Abstract: A DC/DC converter 100 has a DAC 40 that receives a code associated with desired processor operating voltage and sets the reference voltage on its output 41. The reference voltage (VDAC) is boosted by the buffer amplifier 42 to center the droop along the median load. A sensed current signal ICS 22 is proportional to the load current Io 24 and can be either inductor current, or switch current, or diode (or synchronous switch) current. In all cases it is scaled down by the factor of gain Gc. A droop control feedback circuit includes an error amplifier 50. It has two inputs. In one embodiment the gain of the converter is by a signal inversely proportional to the processor clock frequency FCPU max and transformed to the current IDROOP 32 that creates the voltage drop across the resistor R1. The other input is coupled to the buffer amplifier output.

Abstract: A DC/DC converter 100 has a DAC 40 that receives a code associated with desired processor operating voltage and sets the reference voltage on its output 41. The reference voltage (VDAC) is boosted by the buffer amplifier 42 to center the droop along the median load. A sensed current signal ICS 22 is proportional to the load current Io 24 and can be either inductor current, or switch current, or diode (or synchronous switch) current. In all cases it is scaled down by the factor of gain Gc. A droop control feedback circuit includes an error amplifier 50. It has two inputs. In one embodiment the gain of the converter is by a signal inversely proportional to the processor clock frequency FCPU max and transformed to the current IDROOP 32 that creates the voltage drop across the resistor R1. The other input is coupled to the buffer amplifier output.

Abstract: A DC-to-DC converter has a pulse width modulator PWM) and a hysteretic (ripple) modulator. For low current loads, the hysteretic modulator is selected; for high current loads, the PWM is selected. A mode selection switch senses the polarity of the switched output voltage at the end of each switching cycle. If the polarity changes from one cycle to the next, the mode may be instantly changed to the other mode. Counters are used to record the polarity at the end of each cycle and switching from one mode to another can be delayed by the counters to prevent changing modes based on spurious output voltage fluctuations.

Abstract: A low temperature coefficient resistor(TCRL) has some unrepaired ion implant damage. The damaged portion raises the resistance and renders the resistor less sensitive to operating temperature fluctuations. A polysilicon thin film low temperature coefficient resistor and a method for the resistor's fabrication overcomes the coefficient of resistance problem of the prior art, while at the same time eliminating steps from the BiCMOS fabrication process, optimizing bipolar design tradeoffs, and improving passive device isolation. A low temperature coefficient of resistance resistor (TCRL) is formed on a layer of insulation, typically silicon dioxide or silicon nitride, the layer comprising polysilicon having a relatively high concentration of dopants of one or more species. An annealing process is used for the implanted resistor which is shorter than that for typical prior art implanted resistors, leaving some intentional unannealed damage in the resistor.

Abstract: A silicon semiconductor die comprises a heavily doped silicon substrate and an upper layer comprising doped silicon of a first conduction type disposed on the substrate. The upper layer comprises a well region of a second, opposite conduction type adjacent an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon. Both the well region and adjacent edge termination zone are disposed at an upper surface of the upper layer, and an oxide layer overlies the upper layer and the edge termination zone. A process for forming a silicon die having improved edge termination. The process comprises forming an upper layer comprising doped silicon of a first conduction type on a heavily doped silicon substrate, and forming an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon at an upper surface of the upper layer.

Abstract: An integrated circuit having a MOS structure with reduced parasitic bipolar transistor action. In one embodiment, a MOS integrated circuit device comprises a substrate having a working surface, at least one body region and for each body region a source and a layer of narrow band gap material. Each body region is formed in the substrate proximate the working surface of the substrate. Each layer of narrow band gap material is positioned in a portion of its associated body region and proximate the working surface of the substrate. Each layer of narrow band gap material has a band gap that is narrower than the band gap of the substrate in which each of the body regions are formed. Each source region is formed in an associated body region. At least a portion of each source region is also formed in an associated layer of narrow band gap material.

Abstract: A silicon semiconductor die comprises a heavily doped silicon substrate and an upper layer comprising doped silicon of a first conduction type disposed on the substrate. The upper layer comprises a well region of a second, opposite conduction type adjacent an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon. Both the well region and adjacent edge termination zone are disposed at an upper surface of the upper layer, and an oxide layer overlies the upper layer and the edge termination zone. A process for forming a silicon die having improved edge termination. The process comprises forming an upper layer comprising doped silicon of a first conduction type on a heavily doped silicon substrate, and forming an edge termination zone that comprises a layer of a material having a higher critical electric field than silicon at an upper surface of the upper layer.

Abstract: A method and apparatus for internally testing portions of a subscriber loop interface circuit. Testing may be conducted on a semiconductor circuit including the subscriber loop interface circuit. The portion of the subscriber loop interface circuit being tested may be the ring trip detector and/or the off-hook detect circuit. Testing of may be conducted without disabling the capability of the subscriber loop interface circuit to monitor the hook status of a subscriber.