An All-Digital CMOS Area-Efficient Delay Line
An all-digital CMOS area-efficient delay line by using a pulse-shrinking scheme is presented for time
measurement. The previous mechanism applied in the all-digital delay line adopts a short channel length of the transistor to
achieve a high time resolution. However, the delay time of the time-measurement delay line is short to result in a narrow
dynamic range. To widen the range, the longer delay line is required to increase the circuit area considerably. The presented
all-digital pulse-shrinking scheme achieves a significant improvement in resolution. Thus, a long length of the transistor is
used to improve the range considerably and reach a high resolution. The delay lines with different channel lengths were
implemented in a TSMC 0.35-μm CMOS process for verification. The result shows that a significant improvement in cost
and a high resolution were achieved by using the presented scheme.
Keywords- CMOS, Pulse Shrinking, Time Measurement, Delay Line.