A sense amplifier includes a first cascode transistor, a second cascode transistor, a first feedback circuit, a second feedback circuit, and a comparator. The drain of the first cascode transistor is connected directly to a first voltage source. The gate of the first cascode transistor is connected to the first feedback circuit and a first input of the comparator, and the source of the first cascode transistor is connected to the first feedback circuit and a first column decoder. The drain of the second cascode transistor is connected directly to a second voltage source. The gate of the second cascode transistor is connected to the second feedback circuit and a second input of the comparator, and the source of the second cascode transistor is connected to the second feedback circuit and a second column decoder.