Cascaded-inverter ring oscillator constant voltage source - has current limiting pairs of transistors with input capacitance and resistance for delaying output of previous stages

摘要

The constant voltage source has a number of inverters (1-5) each comprising two p-channel MOSFETs (e.g. 1a,1b) and two n-channel MOSFETs (1c,1d) in series cascaded between an input node (IN) and an output node (OUT). One pair (a,d) of transistors has a channel of such size that the input capacitance is sufficient to delay the signal from the preceding stage by a predetermined time interval. The current drawn by this transistor pair is limited by another pair (b,c) connected to a current-mirror circuit (6) of a diode-connected complementary MOSFET pair (6a,6b). ADVANTAGE - Reduced power consumption by output signal being held at reduced level in prescribed cycle of operation.