1-A and-120 mA thin-film multijunction thermal converters

We report on the development of thin-film multijunction thermal converters for the measurement of AC currents up to 10 A without relying on parallel current shunts. The materials and designs chosen for these devices have been optimized to provide high accuracy over a wide range of input levels and frequencies. Preliminary measurements on a 10-A chip made with a copper-gold heater indicate that its ac-dc difference is nearly zero from 10 Hz to 100 kHz, and that the AC-DC difference is independent of input current level.