Built-in current sensor designs based on the bulk-driven technique

Recently the bulk-driven current mirror technique has been employed in built-in current sensors for low voltage environment. This paper proposes 4 arrangements of built-in current sensors based on this technique. They are mainly different in biasing schemes and respectively take the advantages of simplicity, accuracy, flexibility and low power dissipation. From experiments, these sensors have small performance impact which causes only 0.3 V of power supply voltage drop and 0.3 ns delay of circuit speed degradation. These sensors require single external power supply and small area overhead.