Intelligent test head for automatic test system

Abstract

An intelligent test head which can be plugged into an existing computer-controlled automatic test system that is adapted to carry out certain tests on integrated circuits and discrete devices, the test head making it possible for the system to execute special tests which the system is otherwise incapable of performing. The existing system includes a main frame computer associated with a programmer. A device under test is linked by a pin electronics board to the computer through a relay interface board which acts to selectively couple a forcing supply, a function generator or other testing sources to the device, which sources are appropriate to the normal test capabilities of the system. When plugged into the system, the intelligent test head is interposed between the pin electronics board and the device then under test. The head includes a microprocessor and firmware associated therewith which stores the various test functions and the necessary timing and sequencing for the special tests, the head also being provided with a function generator and other testing sources. The microprocessor is intercoupled with the main frame computer through a translation module so that data acquired by the special function test head can be translated into the same machine language format that the main frame computer uses to communicate within itself.