Trends for microcontroller device testing

The cost of test, quality of test, and the push for increased device capability create a unique set of challenges for ATE device power suppliers. A key component to the cost of test of microcontrollers is equipment utilization. Low pin-count microcontrollers may be tested from 32 to 128 sites in parallel and the device requires two or three separate power supplies. The ability to isolate faults in the device can provide valuable feedback to design and product engineers early in the device's life cycle. For legacy purposes, power supplies for I/O domains and embedded converters require operation in the 3.3-V to 6-V range with only 10% to 20% of the current required by the core. The occurrence of voltage excursions is most commonly associated with a sequence of instrument transitions and connections. One common cause of voltage excursion in a change to the power supply's meter range. An ideal serial shunt configuration ensures that nothing is switched out of the shunt path when the current meter range changes are made.