The circuit shown in Figure 30.31 is the sense amplifier used to read data from the cell. As soon as the SE signal goes HIGH the amplifier senses the difference between the and voltages and produces an output voltage appropriately. The access time of the memory, which is defined as the time between the initiation of the read operation and the appearance of the output, mainly depends on the performance of the sense amplifier. So the design of the sense amplifier forms the main criteria for the design of memories. The one that is shown here is a simple sense amplifier.
Fig 30.31: Differential Sense Amplifier
Figure 30.31 shows the block diagram of a memory cell with all the peripherals
Fig 30.32: Block Diagram Of A Memory Cell With All Its Peripherals
and 
voltages and produces an output voltage appropriately. The access time of the memory, which is defined as the time between the initiation of the read operation and the appearance of the output, mainly depends on the performance of the sense amplifier. So the design of the sense amplifier forms the main criteria for the design of memories. The one that is shown here is a simple sense amplifier. 
