Thomas Gerard Weldon

US Patent:

44954620, Jan 22, 1985

Filed:

Mar 3, 1983

Appl. No.:

6/471945

Inventors:

Thomas G. Weldon - Milpitas CA

Assignee:

Raytheon Company - Lexington MA

International Classification:

G01R 1918

US Classification:

324120

Abstract:

A test circuit for determining the current produced by a current source device with a predetermined, non-zero voltage at the output of the device. The circuit includes a current to voltage converter circuit for converting the current produced by the current source device, typically a digital-to-analog converter (DAC), into a corresponding voltage. A control voltage source is coupled to the output of the current source device and to the current to voltage converter circuit through a coupling circuit. The coupling circuit couples a predetermined portion of the control voltage to the output of the current source device and to the current to voltage converter circuit with the voltage produced by the current to voltage converter being proportional to the current produced by the current source device and independent of the control voltage. With such an arrangement, the compliance voltage range of a DAC may be accurately measured. Further, the test circuit enables the non-linearity and relative accuracy of a DAC to be determined with the output of the DAC having a non-zero voltage at its output.