US Patent 10224088 Memory with a global reference circuit

A memory includes a global reference circuit for generating a signal that controls the resistance of a plurality of reference devices used to read data in memory cells by sense amplifiers of the memory. The signal is generated by an output of an operational amplifier of the global reference circuit. The operational amplifier includes a first input whose voltage is set by flowing current through a reference circuit and a second input whose voltage is set by flowing current through a master reference device. The signal controls the resistance of the master reference device such that the voltages of the inputs of the operational amplifier match.