is identical to the memory resistor a good tracking of resistance variation due to temperature changes can be achieved the sense amplifier 133 includes a cmos inverter similar to the circuit of fig3 the inverter also acts as a voltage comparator with an internal reference voltage the internal reference voltage is the toggle voltage of the inverter typically about 0 5v if the input to the inverter is less than the toggle voltage the output of the inverter will be high to the power supply voltage if the input to the inverter is higher than the toggle voltage the output of the inverter will be low to the ground potential fig1 is an output response of the temperature compensated sensing circuit of fig1 the data used in this figure is the same data used in fig4 and 5 with the temperature dependent element 135 sets to the low resistance state since the temperature dependent element 135 is identical to the low resistance state of the memory resistor the gate voltage v g of the bias transistor 138 tracks with temperature and is always at with v dsat is the saturation voltage and v th is the threshold voltage of the transistor 138 and both are a weak function of temperature the output response curve 142 in fig1 is a normalized response curve since the current through the memory resistor varies with temperature similarly the memory resistor load lines in fig1 are drawn from the effective resistance of the memory resistor the effective resistance is calculated.