Patent ID: 6600690
Filing Date: 2003-07-29
Classification: G11C

Abstract:
A sense amplifier for sensing a state of a memory cell that is programmable to either a high state or a low state, comprising:a first high reference memory cell that is programmed to the high state; a first low reference memory cell that is programmed to the low state; a first transistor, of a first conductivity type, having a first current electrode coupled to the memory cell, a control electrode for receiving a bias voltage, and a second current electrode for providing an output signal; a second transistor, of a second conductivity type, having a first current electrode coupled to the second current electrode of the first transistor, a second current electrode coupled to a first voltage terminal, and a control electrode; a third transistor, of the first conductivity type, having a first current electrode coupled to the first high reference memory cell, a control electrode coupled to the control electrode of the first transistor, and a second current electrode; a fourth transistor, of the second conductivity type, having a first current electrode coupled to the second current electrode of the third transistor, a control electrode coupled to the first current electrode of the fourth transistor and to the control electrode of the second transistor, and a second current electrode coupled to the first voltage terminal; a fifth transistor, of the first conductivity type, having a first current electrode coupled to the first low reference memory cell, a control electrode coupled to the control electrode of the first transistor, and a second current electrode for providing a reference out signal; and a sixth transistor, of the second conductivity type, having a first current electrode coupled to the second current electrode of the fifth transistor, a control electrode directly connected to the first current electrode of the sixth transistor and to the control electrode of the fourth transistor, and a second current electrode coupled to the first voltage terminal.