Apparatus and method of testing CML circuits

DETAILED DESCRIPTION A test apparatus for CML integrated circuits is shown herein.
The apparatus has a test unit which is capable of determining differences in the pulses and various waveforms that it receives.
The differences analyzed by the test unit include time delays.
That is the differences in the arrival of the input pulse or waveform and the occurrence of the output pulse or waveform from the CML circuit.
As utilized herein the inputs to the CML circuit under test will be referred to as pulses and the output referred to as a waveform.
The test unit is capable of actuating two pulse generators.
Each pulse generator is capable of producing a pulse of a predetermined shape.
The shaped pulses are applied to their respective power splitters.
Each power splitter is capable of providing the shaped pulse applied thereto at two of its outputs.
One output of the power splitters is connected to the test unit, and the other output is connected through a matrix of relays to an appropriate fixture having the CML integrated circuit under test attached thereto.
The relays are electrically actuated and each relay has a connector movable between two electrical contacts.
A controller unit provides the necessary switching signals to control the switching of the relays.
The relays are interconnected to form a number of submatrices and a pin connection matrix.
The pin connection matrix is adapted to connect many of the submatrices to a particular pin of the CML circuit.
Each pin of the CML integrated circuit is connected to the pin connection matrix through the fixture.
Two of the submatrices obtain their inputs from the other output of the power splitters.
Another submatrix is connected to a noncritical pulse generator which is also actuated by the test unit.
Another of the submatrices is utilized to transfer the output waveform to a waveform output of the matrix.
This output is connected through a probe Tee to the test unit.
The controller which provides the switching signals to the relays is ultimately under the control of the test unit