Delay circuit, circuit system with delay circuit and method thereof

Abstract

The embodiments of the present invention disclose a delay circuit. The delay circuit comprises an inverter, a load capacitor, and a first voltage clamping module, wherein the first voltage clamping module generates a voltage drop configured to prolong the propagation delay time of the delay circuit as the power supply voltage decreases. The power supply dependent delay circuit may have a much larger propagation delay time at low power supply voltage than it at high power supply voltage at the rising-edge or falling-edge of an input signal.

Description

technical field [0001] The present invention relates to the field of circuits, and more specifically, the present invention relates to a delay circuit. Background technique [0002] Delay circuits are widely used in the semiconductor industry. Typically, delay circuits are composed based on eg figure 1 Complementary metal-oxide-semiconductor (CMOS) inverter cells 10 are shown. As shown in the figure, when the CMOS inverter unit 10 is working, the P-type MOSFET 101 or the N-type MOSFET 102 together with the load capacitor 104 form a resistor-capacitor (RC) loop. This loop has a propagation delay that delays the incoming signal. Generally speaking, the CMOS inverter unit 10 is not affected by the power supply voltage and changes drastically. [0003] However, in some applications, it is necessary to change the delay time following the change of the power supply voltage Vcc, so as to prevent the circuit system from being disturbed by the fluctuation of the power supply volt...

AI Technical Summary

Problems solved by technology

Although a digital delay circuit with a feedback loop can address these needs, it is costly, complex and consumes a large circuit area

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