A differential voltage clamped current mode delay cell is proposed and
a three-stage differential ring oscillator is implemented. Owing to t
he nature of this current mode, with voltage clamping and robustness a
gainst noise, experimental results show that the supply sensitivity is
very low at approximately 0.1-0.2%/V in the 500-800 MHz range, with i
ts tuning range over 1 decade up to 1.38 GHz.