A Wide Range On-Chip Leakage Sensor Using a Current-Frequency Converting Technique in 65-nm Technology Node

As technology moves toward the submicron regime, leakage current due to aggressive scaling and parameter variation has become a major problem in high-performance integrated circuit (IC) designs. Therefore, accurate measurement of the leakage current flowing through transistors has become a critical task for better understanding of process and design. In this study, we propose a simple on-chip circuit technique for measuring a wide-range static standby (or leakage) current in a 65-nm technology with high accuracy. The circuit consists of a current amplifier, a bias stabilizer, and a voltage-controlled oscillator. The proposed leakage sensor is designed to measure leakage currents from 20 pA to 20 nA. Simulation results show that the proposed sensor has less than 8.4% error over a wide range of leakage currents (i.e., three orders of magnitude). Chip measurement results also indicate that the proposed leakage sensor is operating properly and measures the standby leakage current values of the devices under test within the possible range at different temperatures. The power consumption of the proposed leakage sensor was 0.6 mW when the leakage current was 1 nA, and the active area was 0.007 mm2.