What is the Difference Between Latch and Flip-Flop?

The main difference between a latch and a flip-flop is their triggering mechanisms and the way they respond to input changes. Here are the key differences between latches and flip-flops:

1. Triggering: Latches are level-triggered, meaning their output changes whenever the input changes, regardless of the state of the control signal. Flip-flops, on the other hand, are edge-triggered, meaning they change state only when the control signal goes from high to low or low to high.
2. Clock Signal: Flip-flops require a clock signal to synchronize their operations, while latches do not have a clock signal.
3. Design: Flip-flops can be designed using latches along with a clock, while latches can be designed using logic gates.
4. Sensitivity: Flip-flops are sensitive to the applied input and the clock signal, while latches are only sensitive to the input.
5. Operation Type: Flip-flops perform synchronous operations, relying on the present and past input bits along with the past output and clock pulses. Latches perform asynchronous operations, depending on the present and past input along with the past output binary values.
6. Robustness: Flip-flops are generally more robust than latches.
7. Usage: Flip-flops are commonly used in sequential circuits like counters, while latches can be used for designing sequential circuits but are not generally preferred.

In summary, latches are level-triggered devices that change their output immediately based on the applied input, while flip-flops are edge-triggered devices that change state when the control signal transitions from high to low or low to high. Flip-flops are typically used in synchronous sequential circuits, while latches are more suitable for asynchronous sequential circuits.

Comparative Table: Latch vs Flip-Flop

Here is a table comparing the differences between latches and flip-flops:

Both latches and flip-flops are bistable devices that can store one bit of information. However, latches are level-triggered and have continuous input sampling, while flip-flops are edge-triggered and sample their inputs at specific times defined by the clock signal. This difference in triggering results in latches being faster than flip-flops. Latches are also leaner in terms of power consumption and area, as they have fewer gates compared to flip-flops. Gated D latches are commonly used latches, while D-type flip-flops are the most commonly used flip-flops.