Texas Instruments Corporation

Mark A Burns

Turker Kuyel

Ben D Hodge

David Ta-wei Kao

Craig D Force

A test apparatus () comprising a single handler () is coupled to a first tester () and second tester (), wherein the first () and second () testers are coupled together. A first test procedure is performed on a set of second IC's using the first tester (), simultaneously while a second test procedure is performed on a first set of IC's using the second tester (). Sets of IC's may be tested in parallel by a plurality of testers () within a single handler (). The first () and second () testers may be coupled to a multiplexer () to allow the use of a single test head (), which avoids having to make contact to the integrated circuit more than once, which is particularly advantageous in wafer probe testing.

Parallel integrated circuit test apparatus and test method

A clipping circuit ( ) for clipping an input signal to a level corresponding to a regulated power supply voltage (AVDD). The clipping circuit ( ) includes a current mirror-like arrangement having a reference transistor ( ) and a mirror transistor ( ) The input signal (BDATA) is received at the drain of the mirror transistor ( ), with the source of the mirror transistor ( ) producing the output signal (CLPBDATA). The reference transistor ( ) receives a bias current (I ) that is mirrored by the mirror transistor ( ) to limit the pull-up drive of the mirror transistor ( ) in pulling up the output (CLPBDATA). Disclosed embodiments of the clipping circuit ( &Prime;) include a current source ( ) for producing a DC bias current (I ), and a charge pump ( ) for producing a transient bias current (IPUMP).

Signal clipping circuit

A technique for translating design test bench generated signals into an Automated-Test-Equipment compatible format using existing digital pattern conversion tools. The technique uses sigma-delta modulation technology to allow conversion of analog and mixed signal stimuli into digital representations that can be converted for use in the target tester using existing digital pattern conversion tools.

Capture and conversion of mixed-signal test stimuli

The present invention provides a method ( ) of testing analog-to-digital converters (ADCs) ( ) that shortens the test time required to measure INL and DNL by advantageously converting the ADC ( ) into a digital to analog converter (DAC) ( ). The conversion from ADC to DAC is accomplished using a DfT test mode, which reconfigures the ADC into a DAC using a delta modulation circuit. Since DACs can be tested much more efficiently than ADCs, the ADC test time is substantially reduced by the invention.

Design-for-test circuit for successive approximation analog-to-digital converters

A digital to analog converter includes a network of impedance components having a plurality of nodes having associated voltages. A tap is coupled to one or more associated one of the plurality of nodes to source or sink electrical current relative to the associated node(s). A switching system is operative to couple a selected one of the nodes to an output according to a digital input word and thereby provide an analog voltage corresponding to the digital input.

Piecewise linear digital to analog conversion

A method of measuring non-coherent electrical signals using either windowed or non-windowed digital signal processing. The method includes the steps of providing a digitized version of the non-coherent electrical signal; generating a matrix A of correlations between sine and cosine components of known correlation frequencies and sine and cosine components of signal frequencies; generating an inverse matrix A,of the correlation matrix; generating a second matrix B of correlations between sine and cosine components of the correlation frequencies and the digitized non-coherent electrical signal; and generation of a third matrix C which represents the measured amplitudes of the sine and cosine components of the non-coherent electrical signal.

Method and apparatus to measure non-coherent signals

A system and method for measuring jitter. One class of embodiments is particularly useful for testing the aperture jitter of a high speed Analog to Digital (A/D) converter. Aperture jitter in a Sample and Hold circuit (S/H) or in an A/D converter introduces noise into the sampled signal, which is more extreme in areas of the input waveform that have a steep positive or negative slope. The preferred embodiment allows an easy and inexpensive way to measure aperture jitter in S/H and A/D circuits. The technique can also be adapted for measuring edge jitter in digital clock signals or in analog sine wave signals.

Method and apparatus to measure jitter.

A signal generation circuit comprises a memory operable to store a digital signal comprising a stream of one-bit samples that were generated using sigma delta modulation. The signal generation circuit further comprises a signal modification circuit coupled to the memory and operable to receive the digital signal from the memory and to introduce a DC level shift to the digital signal, wherein the output of the signal modification circuit can be filtered to produce an analog signal.

Method and apparatus to generate mixed signal test stimulus

An undersampling digital testability circuit 20 includes a bus 15, a data capture array 22 and a divider circuit 18. Divider circuit 18 provides an enablement signal to data capture array 22 that undersamples data travelling along the bus 15 at high data rates thereby effectively testing the integrity of high data rate transfers without the disadvantages of prior art test methodologies.

Undersampling digital testability circuit

An apparatus measures a repetitive signal in a coherent manner, including a signal generating circuit to output the repetitive signal in accordance with first clock signals which are generated by a first clock circuit. A sampling circuit samples the repetitive signal in accordance with second clock signals to output a sampled signal, the second dock signals are output by a second clock circuit. An output circuit stores the sampled signals and outputs a reconstructed signal based on said sampled signal.

Coherent undersampling digitizer for use with automatic field test

An apparatus measures a repetitive signal, including a signal generating circuit to output the repetitive signal in accordance with first clock signals which are generated by a first clock circuit. A sampling circuit samples the repetitive signal in accordance with strobe signals to output sampled signals, the strobe signals are output by a strobe generator circuit. An output circuit stores the sampled signals and outputs a reconstructed signal based on said sampled repetitive signal.

Undersampling digitizer with a sampling circuit positioned on an

The present invention includes a method of eliminating interference from an undersettled electrical signal, the undersettled electrical signal including a test signal at a known frequency. One embodiment of the present invention includes a method comprising the steps of providing a digitized version of the undersettled electrical signal (at 46); generating a frequency spectrum of the digitized version of the undersettled electrical signal (at 56); spectrally interpolating the frequency spectrum to generate an interference signal frequency spectrum (at 65); and subtracting the interference signal frequency spectrum (at 65) from the undersettled signal frequency spectrum (at 56) generating a settled signal spectrum (at 75). Another embodiment of the present invention includes a system comprising means (40 or 45) responsive to the undersettled electrical signal for producing a digitized version of the undersettled electrical signal (at 46); means (50) responsive to the digitized version of the undersettled signal for transforming the digitized version of the undersettled signal into a transformed signal; and means (60 and 70) including a spectral interpolator (60) responsive to the transformed signal for removing interference from the transformed signal generating a settled signal output (at 75).

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McKinney, TX, United States of America

Mark A Burns