Disclosed is a method that uses a built-in ATE power supply to relay current measurements from a standalone circuit or external power supply back to the tester. This extends the current measurement capabilities of an existing ATE device under test (DUT), while maintaining compatibility with existing test application interfaces.

Background

Currently, ATE tester power supplies may not provide the required level of current measurement accuracy. ATE tester power supplies may also run out of output power, and must be supplemented with an external power supply which would have its own current measure circuit. A New Current Measurement Unit (NCMU) may be developed to overcome these problems. If used, the data from the NCMU must be communicated back to the tester, however most communication links to the tester are slow, negatively impact test time, and complicate programming of the NCMU (see Figure 1). These communication links require new code to be developed and integrated for the NCMU.

General Description

The New Current Measurement Unit (see Figure 2) is either a part of the external power supply which provides actual power to the DUT, or it is an independent unit. Current measure data which is collected from this unit  is converted via the microprocessor and fed back to the precision load. The ATE Tester Power Supply connected to the load uses its internal current measure circuit to monitor...