Low Voltage Ultra-Low Power PVT Independent and High PSRR Voltage Reference for Zero-Energy 6G Application

There are two possible solutions to address the energy needs of power-hungry devices such as IoT and wireless 5G/6G communications devices. One is the reduction of the power consumption of the device's internal circuitry, and the other is the continuous-intermittent charging of the device battery through ambient energy harvesting to extend longevity. Henceforth, this work focused on the integrated circuits design and implementation of the internal voltage-supply-reference component blocks for its future integration on the system-on-chip IoT device. A resistor-less low-voltage low-power voltage reference circuit is proposed which can operate as low as 350 mV with power consumption of 6.2 nW (IQ = 7.77 nA) @ room temperature. The proposed topology which is implemented in 65 nm process node operates in weak inversion region in order to achieve low-voltage low-power operation. Understanding that devices biased in weak inversion are much more sensitive to temperature variations and to process variability, in particular to threshold voltage dispersion; a circuit compensation technique was employed to minimize the circuit dependence to threshold voltage dispersion. Simulation results shows that the proposed voltage reference is independent to process, voltage, and temperature variations (PVT). Moreover, Monte Carlo Analysis shows that Vth dependence can be reduced to less than ± 1% (3σ) and with minimum PSRR of 50.52 dB and 56.19 dB at 100 Hz and 10 MHz, respectively. Consequently, resistor-less design and implementation leads to have a very small die area which is advantageous in biomedical, portable applications, and wireless sensor networks.