Sense amplifiers and semiconductor memory devices for reducing power consumption and methods for operating the same

A sense amplifier comprising:

• a current amplifier configured to output a first and a second voltage signal in response to a first control signal, the first and second voltage signals being output based on a detected current difference between a pair of input/output lines;
• a voltage amplifier configured to generate a third and a fourth voltage signal based on a detected voltage difference between the first and second voltage signals, the third and a fourth voltage signals being generated in response to a second control signal;
• a first latch circuit configured to latch the third and fourth voltage signals, and output a first output signal in response to the second control signal;
• a second latch circuit configured to latch the first and second voltage signals and output a second output signal in response to a third control signal;
• and
• an output circuit configured to perform a logic operation on the first output signal and the second output signal, and output a result of the logic operation as a resultant signal.