All Digital Minimum Energy Point Detection for Ultra Low Power CMOS Circuits

An all digital Minimum Energy Point (MEP) detection circuit consisting of activity, leakage and temperature sensors is implemented using 0.18
$\mu \mathrm{m}$
CMOS. A DC-DC Switched Capacitor (SC) converter array provides various voltages whose energy is being sensed. The proposed circuit successfully finds the MEP for a 4-bit and an 8-bit adder obtained at runtime and locates it at 400
$\text{mV}$
and 350
$\text{mV}$
in the subthreshold region. The digital MEP detection circuit consumes 3.36
$\text{nJ}$
for 4-bit and 3.4
$\text{nJ}$
for 8-bit adder circuits.