Luminous intensity adjustment circuit and method thereof

Abstract

The invention discloses a luminous intensity adjusting circuit and a method thereof. The circuit comprises a tri-state controller, a holding circuit, a buffer, an optical sensor, a transconductance amplifier, an inverting amplifier, an analog-to-digital converter and a processor. A voltage / current pulse signal of a certain pulse width is input into the signal input end of the tri-state controller. The output end of the tri-state controller is connected with the holding circuit. The output end of the holding circuit is connected with the buffer. The output end of the buffer is connected with the optical sensor. The output end of the optical sensor is connected with the transconductance amplifier. The output end of the transconductance amplifier is connected with the inverting amplifier. The output end of the inverting amplifier is connected with the analog-to-digital converter. The output end of the analog-to-digital converter is connected with the processor. The output end of the processor is connected with the control input end of the tri-state controller. According to the technical scheme of the invention, through dynamically adjusting the luminous intensity, the DC component of a signal is fixed, so that only the AC component of the signal needs to be recognized. Therefore, the requirement on the ADC accuracy is greatly broadened. Meanwhile, the power consumption and the cost overhead are reduced.

Description

technical field [0001] The invention relates to a luminous intensity adjusting circuit and a method thereof. Background technique [0002] Since the DC component of the physiological signal has a large dynamic range, but the AC component is very small, in order to identify the AC component, a high-precision ADC (usually above 18bit) is required, which results in huge power consumption and cost overhead. [0003] The present invention fixes the DC component of the signal by dynamically adjusting the luminous intensity, and only needs to identify the AC component, which greatly relaxes the requirement for ADC precision and reduces power consumption and cost. Since the signal received by the receiving tube is determined by the luminous intensity and the signal itself, as the DC component of the signal changes, the luminous intensity is dynamically adjusted so that the DC component in the signal received by the receiving tube remains constant; otherwise, due to the high sensitiv...

AI Technical Summary

Problems solved by technology

[0002] Since the DC component of the physiological signal has a large dynamic range, but the AC component is very small, in order to identify the AC component, a high-precision ADC (usually above 18bit) is required, which causes great power consumption and cost overhead

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