Angle and length measurement circuit has detectors with test signal and external connections through multiplexer to second chip

摘要

An angle and length measurement circuit has photo diode or Hall effect detectors (310, 320, 330, 340) connected through a multiplexer (140) on a chip (100) with test connection pads (160) to a contact pad (260) and probe surface (261) on a second chip (200) on a separate substrate with analogue to digital converters (250) and a test signal source (150) connected to the amplifier (130, 135) inputs.