Data sensing apparatus of a read only memory device

摘要

A data sensing apparatus particularly useful for sensing a ROM device. The apparatus can be used with various voltage level devices because it has an adjustable load. A first load element is connected to the voltage source applied to the ROM device. A second load element is connected in parallel with the first load element. A switching element is connected to the first load element and provides a path for a sensing current of the ROM device. An inverter, responsive to the sensing current, controls the switching element. An amplifier, connected to the switching element, provides a useful output indicative of the sensing current of the ROM device. A voltage level detector detects the voltage level of the voltage source. It disables the second load element so as to increase the load when the voltage level of the voltage source is higher than a predetermined value.