High voltage driver circuit with fast current limiting for testing of integrated circuits
AssigneeAltera Corporation
InventorErnest Allen, III
Life of this patent
Estimating the term…
Abstract
A circuit that provides for digitally programmable high voltage drive, as well as fast current limiting capability for testing of integrated circuits. The circuit also provides for digitally programmable slew rate control for controlling the rise and fall times of an output voltage. Integrated circuits requiring low voltage and high voltage tests at different speeds and with different current limiting conditions, or low and high current forcing with different voltage clamp levels, or a mixture of the two can be tested in a single continuous test pattern using the circuit of the present invention.
Claims9
In a test system having a diode bridge wherein an integrated circuit under test couples to a first terminal of the diode bridge, a method for testing the integrated circuit comprising the steps of:
- (a) loading first digital test data into a first register;
- (b) using a digital to analog converter to convert said first digital test data to first analog current signal;
- (c) directly applying said first analog current signal to a current-controlled current mirror circuit;
- (d) coupling an output of said current-controlled current mirror circuit to a second terminal of the diode bridge;
- and
- (e) varying an amount of current flowing through said current-controlled current mirror circuit to change test parameters at substantially the same speed as the speed of execution of the functional test.
A processor-controlled circuit for testing of integrated circuits, comprising:
- a diode bridge having a first terminal coupled to a device under test;
- a digitally programmable current-controlled current source coupled to a second terminal of said diode bridge;
- a digitally programmable reference voltage generator coupled to a third terminal of said diode bridge;
- and
- a digitally programmable current-controlled current sink coupled to a fourth terminal of said diode bridge,
- each one of said digitally programmable current-controlled current source and current sink comprises:
- a register coupled to the processor, for storing programming data;
- a digital to analog converter having a digital input coupled to said register, and an analog current output;
- and
- a current-controlled current mirror circuit having a first terminal coupled to said analog current output of said digital to analog converter and a second terminal coupled to a terminal of said diode bridge,
- wherein, in response to said programming data, said digital to analog converter is capable of varying an amount of current flowing through said current mirror circuit to change test parameters during the execution of a functional test at substantially the same speed as the speed of execution of the functional test.
Dependencies are inferred from the claim text.