Design and Implementation of a Low-Power VCO-based ADC for IoT Applications

The paper presents the design of an Analog-to-Digital Converter (ADC) using Voltage Controlled Oscillator (VCO)based ADC techniques, calibrated for Internet of Things (IoT) applications with a power supply of only 1.3 V targeting Bluetooth Low Energy (BLE). The flexible integration between analog and digital elements of the VCO-based ADC technology minimizes design time and energy consumption. The paper also focuses on maximizing the performance of VCO through the use of low-pass filtering, analog calibration to lower variability, oversampling to increase signal-to-noise ratio (SNR), and the removal of unneeded samples to improve VCO’s output resolution. The free and open-source SkyWater 130nm PDKs and tools were employed for both design and simulation. The simulation results show that the proposed ADC achieves 8 -bit effective number of bits (ENOB), with a 50 dB SNR and a just 0.042 mW power consumption.