Disclosed are methods and apparatus for determining whether to perform burn-in on a semiconductor product, such as a product wafer or product wafer lot. In general terms, test structures on the semiconductor product are inspected to extract yield information, such as defect densities. Since this yield information is related to the early or extrinsic instantaneous failure rate, one may then determine the instantaneous extrinsic failure rate for one or more failure mechanisms, such as electromigration, gate oxide breakdown, or hot carrier injection, based on this yield information. It is then determined whether to perform burn-in on the semiconductor product based on the determined instantaneous failure rate.

Apparatus and methods for managing reliability of semiconductor devices

A wireless communication system, which is provided with a PLL circuit having a plurality of oscillators and is capable of processing two or more transmit and receive signal different in frequency band from one another according to the switching between the oscillators, has a reset means which resets a voltage applied to each of filter capacitors lying within the PLL circuit to a predetermined voltage when the switching between the oscillators is performed.

Wireless communication system

An enhanced concern indicator failure prediction system is provided to predict possible product failures with automatic notification of people as well as systems. The system integrates data mining, spatial analysis, linear programming, narrowcasting, data warehousing, visualization, and text mining. As a result, failure conditions, attributes, complaints, locations, consequences, and sequence of events are analyzed using data mining technologies. This data is fed into an optimization module that assesses the efficiency of the failure process such that failures can be assessed as to their priority. These priorities are then used to feed a triggering engine that triggers notification of systems and individuals using narrowcasting technology. This system is one that allows early warning of potential problems to occur and integrates data from call centers, legacy systems, retailers, manufacturers, vendor supplied parts, and transportation of parts.

Enhanced concern indicator failure prediction system

A phase locked loop (PLL) frequency synthesizer to produce a local oscillator signal for a superheterodyne transmitter for operation at a first and a second RF frequency band that are disparate. The transmitter has a fixed intermediate frequency that is a sizable fraction of the bandwidth of one or more of the RF bands. The superheterodyne transmitter includes a first and a second RF upconverter, each having a local oscillator input coupled to the frequency synthesizer. The synthesizer includes a voltage controlled oscillator (VCO) to provide a VCO frequency signal and a non-integer frequency multiplier to produce a frequency multiplied signal having a frequency wither at the VCO frequency or at a non-integer multiple of the VCO signal depending on a control input. The synthesizer further includes a programmable divider accepting the frequency multiplied signal and dividing the frequency of the by a settable amount, a phase detector to compare the phase of the output of the programmable divider to that of a reference oscillator and produce a phase difference signal; and a loop filter to filter a function of the phase difference to produce a control input to the VCO. The non-integer multiple is selected such that the frequency synthesizer can supply the local oscillator signal for both the first and second RF bands, such that the tuning range of the VCO is a relatively low fraction of the VCO frequency, and such that spurious mixer products do not fall in the frequency bands of operation.

Frequency synthesizer and synthesis method for generating a multiband local oscillator signal

A system and method creating a highly efficient digital amplifier which can take either analog or digital inputs, and produce a high power accurate representation of the input to drive speakers or other low impedance load is described. The system employs a transition detector and delay unit which allows the comparator of the signal modulator to ignore its inputs for a pre-determined number of subsequent clock cycles once an output transition has been detected. Through the use of faster clocks and variable clock cycle skips upon the comparator's output transition, finer resolution of the feedback's clock period for noise-shaping purposes is achieved. Finer resolution of the clock period allows the present invention to employ a more aggressive noise-shaping than previously possible. In another aspect of the invention, additional delta-sigma modulator noise suppression is obtained by using the common bridge implementation of the power output stage with the improvement of configuring the bridge to create a 3-state condition instead of the conventional 2 states. By controlling the two halves of the bridge independently of one another, an output with 3 states makes for improved noise shaping performance.

Method and apparatus for efficient mixed signal processing in a digital amplifier

A method and apparatus for generating two disparate frequency reference signals using a single phase locked loop. The circuit includes a local oscillator for generating a reference signal and a phase comparator for comparing the reference signal with a feedback signal. The output of the phase comparator is converted to a first one of the desired output frequencies by a voltage controlled oscillator. That signal is also fed to a variable frequency divider circuit under control of a Σ/Δ converter which generates a lower frequency signal without creating a secondary frequency tone. The lower frequency signal is the second of the output frequencies. This signal also is fed back to the second input of the phase comparator through a fixed frequency divider.

Phase locked loop for generating two disparate, variable frequency signals

A transmit portion of a WB-CDMA transceiver generates one or more spread data streams having values represented by a single bit, allowing for filtering of spread and combined data streams with a root raised cosine (RRC) filter employing single-bit multipliers. The RRC filter is a digital filter that i) employs multiplication of two values in which the length of at least one value is one bit; ii) is preferably implemented with muxs or a simple logic operator; and iii) may employ upsampling and modulation encoding of filter coefficients to reduce the coefficient length to, for example, one bit. The RRC filter may be an FIR filter having either one-bit or multi-bit coefficients, and apply RRC filtering to a spread user stream either before or after the spread user streams are combined. For some implementations, RRC filters are employed to filter each spread user stream prior to combining several processed user steams. For other implementations, the multi-bit valued data stream representing the combined user streams is upsampled to form an upsampled data stream of single-bit values, and RRC filtering is then applied to the upsampled data stream. Alternatively, implementations may use upsampled RRC filter coefficients that allow RRC filtering on the combined spread user streams represented as a sequence of multi-bit values.

Upsampling filter having one-bit multipliers for multiple spread-data streams

A mixed signal integrated circuit board having decreased sensitivity of analog circuitry to digital circuitry noise is disclosed. In the mixed-signal integrated board of the present invention, a new (second) analog ground is created. This new analog ground is not limited by the manufacturing specification of connectivity to the substrate of the circuit board and is thereby free of transient noise generated by digital components on the board. In a mixed-signal integrated circuit board of the present invention, the new analog ground becomes the preferred ground and is utilized in many sensitive analog applications including voltage and current measurements. The new analog ground is easy to create as it does not involved complicated circuitry. The new analog ground may be created even after the initial circuit schematics has been created.

Digital noise reduction in integrated circuits and circuit assemblies

A digital filter receives signals from each stage of a MASH delta-sigma modulator and filters noise components from the signals prior to combination as a single sequence of values decimation. Each stage of the MASH delta-sigma modulator provides an output sequence of one-bit, binary values, which are then filtered to remove high-order, out of band quantization noise. After filtering, the output sequences are then combined through a cascade-combiner, which may be similar to the pre-processing stage of a MASH delta-sigma modulator architecture. The digital filter processes signals of each stage separately. Consequently, the digital filter does not perform multiplication of two, multi-bit values. Multiplication of two values, the first of which is a one-bit, binary value, may be implemented with a multiplexer selecting either the second value or a zero value based on the first one-bit, binary value (i.e., logic 1 or 0, respectively). Duplicate FIR filters, or a single FIR filter with bit-interleaving by a multiplexer, master-slave delay chain and demultiplexer controlled by system clock transitions, may be used to process the sequences on a single bit basis, replacing multi-bit multipliers of the digital filter with multiplexers. Alternatively, the FIR filter may be implemented with a multiplexer, master-slave delay chain, ROM look-up table and demultiplexer if bit interleaving is employed.

Digital filter and method for a MASH delta-sigma modulator

A circuit and method for detecting mobile ion contamination in a semiconductor device. The circuit uses two transistor structures on the same silicon chip as the circuit being tested to detect the presence (or absence) of mobile ions. The test includes imposing conditions on the silicon chip that may cause any mobile ions present therein to move within the structure. By measuring electrical parameters, such as a band gap voltage, across the transistors before and after the imposition of such conditions, a reliable indication of the presence or absence of mobile ions can be obtained.

Ramin Khoini-Poorfard

Papers

Phase locked loop for generating two disparate, variable frequency signals

Upsampling filter having one-bit multipliers for multiple spread-data streams

Digital noise reduction in integrated circuits and circuit assemblies

Digital filter and method for a MASH delta-sigma modulator

Circuit and method for predicting failure rates in a semiconductor device