Extended bandwidth open-loop VCO based ADC using Interleaving with a single VCO channel

This paper presents a technique to extend the bandwidth of an open-loop Voltage Controlled Oscillator (VCO) based Analogue-to-Digital Converters (ADC), using the Time Interleaving (TI) principle. Unlike the conventional TI implementation, the presented concept uses a single VCO channel and interleaves the sampling circuits. This approach utilizes the wide VCO bandwidth and operates effectively at a higher sampling rate compared to traditional implementations. Furthermore, the proposed design overcomes the speed constraints imposed by the technology, achieving enhanced performance with minimal additional hardware, resulting a highly compact solution. Simulation results demonstrate that, for a 230 MHz bandwidth, the proposed open-loop interleaved VCO-based ADC achieves an SNR of 39.96 dB, compared to 27.33 dB in the conventional open-loop implementation.