Level determining device and method of pulsewidth modulation signal

Abstract

The invention discloses a level deciding device for pulse-width signal and consists of a pulse-width signal generating circuit, a reference voltage reference generating circuit and a deciding circuit. The pulse-width signal generating circuit generates a first pulse-width signal; the reference voltage generating circuit generates a reference voltages signal and the deciding circuit is electrically connected with the pulse-width signal generating circuit and the reference voltages generating circuit and decides the high and low level value of the first pulse width signal according to the reference voltage so as to generate a second pulse-width signal.

Description

technical field [0001] The present invention relates to a judging device and method, in particular to a level judging device and method of a pulse width modulation signal. Background technique [0002] Due to the development of electronic technology, the use of pulse width modulation (Pulse width Modulation, PWM) signals as control signals of electronic components has become more and more popular. [0003] Please refer to FIG. 1 , pulse width modulation is a method of digitally encoding the level of an analog signal, which means converting the analog signal into a square wave with only high and low levels. Its important parameters include high level V H , low level V L And the duty cycle D (Duty Cycle), where the duty cycle D represents the square wave at a high level V H The proportion of the time t in a square wave period T is generally expressed as a percentage. [0004] Please refer to FIG. 2, the known technology is to judge the high and low voltage of the pulse wid...

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Problems solved by technology

However, when the TTL circuit 11 is judging the low level, its maximum judging voltage value is generally 0.8V, that is, when the pulse width modulation signal Sp01 is disturbed by noise during signal transmission, the pulse width modulation signal Sp01 If the low level value is greater than 0.8V, it will cause TTL11 to misjudge it as a high level or fail to judge it, which will cause the TTL circuit 11 or its subordinate circuits to misoperate.

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