Experimental validation of minimum operating-voltage-estimation for low supply voltage circuits

Sub- and near-threshold circuits have been attracting growing interests because they are suitable for realizing extremely low power and low energy circuits. The estimation of the minimum operating voltage (V_DDmin), under which the circuit does not function correctly, is one of the most important issues in their design. In this paper, the distribution of V_DDmin is explored through simulations and measurements. Lognormal model-approximation and a quick V_DDmin estimation method are validated by the measurements of 124k FFs. Assuming that the V_DDmin of a circuit is limited by that of the FFs, V_DDmin distribution for any circuits can be efficiently estimated. The measurements of 192 DCT circuits show that the estimation matches with silicon data very well within 10 mV error.