Analog multi-channel probe system
First Claim
1. An analog multi-channel probe system comprising:
- n input buffer amplifiers, where n is a positive integer, each input buffer amplifier having an input coupled to a test point of a device under test, an output and a control terminal by which the input buffer amplifier can be selectively enabled, whereby when the input buffer amplifier is enabled it provides a test signal at its output;
a test signal selector means comprising n analog multiplexers, one analog multiplexer for each input buffer amplifier with each analog multiplexer having an input coupled to a separate one of the input buffer amplifier outputs, m outputs, where m is a positive integer, and a control terminal by which the multiplexer input can be selectively coupled to any one of its m outputs, the test signal selector means having m selector outputs and the ith output (i=1 . . . m) of each multiplexer being coupled to the ith selector output; and
m output buffer amplifiers, each output buffer amplifier having an input coupled to a separate one of the m selector outputs, an output coupled to an external measurement point and a control terminal by which the output buffer amplifier can be selectively enabled so that any test point may be coupled to any external measurement point as determined by control commands applied to the control terminals of the input and output buffer amplifiers and the analog multiplexers.
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Accused Products
Abstract
A programmable analog multi-channel probe system is embedded within a device under test for coupling test points to external measurement points of the device under test. Programmable input buffer amplifiers are coupled to the test points to couple the data at those points to their outputs when enabled. The data from the input buffer amplifiers are input to respective routers to provide a plurality of outputs. Each common output from the routers is coupled as an input to an output buffer amplifier that provides the data as an output when enabled. The data at the output of the output buffer amplifiers is converted to a differential signal for transmission to the external measurement point by differential input/output amplifiers that have a reference level, selected from a plurality of reference levels including an internal reference level, as an input for comparison with the data from the output buffer amplifiers. A termination circuit may be provided for each output to provide appropriate impedance interface with the measurement points.
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Citations
14 Claims
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1. An analog multi-channel probe system comprising:
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n input buffer amplifiers, where n is a positive integer, each input buffer amplifier having an input coupled to a test point of a device under test, an output and a control terminal by which the input buffer amplifier can be selectively enabled, whereby when the input buffer amplifier is enabled it provides a test signal at its output; a test signal selector means comprising n analog multiplexers, one analog multiplexer for each input buffer amplifier with each analog multiplexer having an input coupled to a separate one of the input buffer amplifier outputs, m outputs, where m is a positive integer, and a control terminal by which the multiplexer input can be selectively coupled to any one of its m outputs, the test signal selector means having m selector outputs and the ith output (i=1 . . . m) of each multiplexer being coupled to the ith selector output; and m output buffer amplifiers, each output buffer amplifier having an input coupled to a separate one of the m selector outputs, an output coupled to an external measurement point and a control terminal by which the output buffer amplifier can be selectively enabled so that any test point may be coupled to any external measurement point as determined by control commands applied to the control terminals of the input and output buffer amplifiers and the analog multiplexers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An analog multi-channel probe system comprising:
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n input buffer amplifiers, where n is a positive integer, each input buffer amplifier having an input coupled to a test point of a device under test, an output and a control terminal by which the input buffer amplifier can be selectively enabled, whereby when the input buffer amplifier is enabled it provides a test signal at its output; a test signal selector means comprising n analog multiplexers, one analog multiplexer for each input buffer amplifier with each analog multiplexer having an input coupled to a separate one of the input buffer amplifier outputs, m+1 outputs, where m is a positive integer, and a control terminal by which the multiplexer input can be selectively coupled to any one of its m+1 outputs, the test signal selector means having m+1 selector outputs and the ith output (i=1 . . . m+1) of each multiplexer being coupled to the ith selector output; m output buffer amplifiers, each output buffer amplifier having an input coupled to a separate one of the m selector outputs, an output coupled to an external measurement point and a control terminal by which the output buffer amplifier can be selectively enabled so that any test point may be coupled to any external measurement point as determined by control commands applied to the control terminals of the input and output buffer amplifiers and the analog multiplexers; an additional output amplifier coupled to the (m+1)th selector output for providing a reference level; and means for converting an output signal provided by an output buffer amplifier to a differential output signal as a function of the reference level. - View Dependent Claims (14)
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Specification