A trim bipolar charge storage memory

A bipolar stored-charge memory cell will be described that consists of a single transistor with an MOS capacitor between emitter and ground. The transistor serves as a bidirectional switch allowing charge to selectively flow into or out of the storage capacitor. The cell requires periodic refreshing of the stored charge since electron-hole generation in the depletion region of the emitter tends to discharge it. However, because most of the charge is stored on the MOS capacitor, storage times of several seconds at room temperature should be expected.