SPAD control circuit, distance sensor module and mobile terminal

Abstract

The invention relates to an SPAD control circuit, a distance sensor module and a mobile terminal, which belongs to the technical field of semiconductor photoelectricity. The control circuit comprisesa divider resistor, an SPAD and a sampling resistor which are sequentially connected in series. The first end of the divider resistor is coupled with the power supply; the second end of the divider resistor is coupled with the cathode of the SPAD; the anode of the SPAD is coupled with the first end of the sampling resistor; the second end of the sampling resistor is grounded; the first end of thesampling resistor is coupled with the output end of the control circuit. The control circuit of the SPAD comprises the divider resistor, the SPAD and the sampling resistor. The divider resistor is used for dividing voltage and limiting current to realize a quenching effect; the sampling resistor is used for outputting pulse voltage as an avalanche signal. According to the circuit, the reverse biasvoltages at the two ends of the SPAD are controlled to be smaller than the avalanche breakdown voltage firstly, the avalanche process of the SPAD is interrupted, an SPAD device is protected, then thereverse bias voltages at the two ends of the SPAD are made to be larger than the avalanche breakdown voltage, and subsequent photon detection is achieved.

Description

technical field [0001] The present disclosure relates to the field of semiconductor optoelectronic technology, in particular to a SPAD control circuit, a distance sensor module and a mobile terminal. Background technique [0002] Mobile terminals such as mobile phones are usually equipped with a distance sensor for detecting the distance between the terminal screen and the obstacle ahead. The distance sensor includes a light transmitter and a light receiver. [0003] In the related art, the optical receiver of the distance sensor adopts SPAD (Single Photon Avalanche Diode, Single Photon Avalanche Diode). SPADs are avalanche photodiodes operating in Geiger mode. Avalanche photodiodes have different working modes such as linear mode and Geiger mode. In the linear mode, the reverse bias voltage across the avalanche photodiode increases, but still less than the avalanche breakdown voltage; The higher the bias voltage, the faster the avalanche current increases, and the avala...

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Problems solved by technology

[0004] However, when the SPAD is in the Geiger mode, as long as the reverse bias voltage of the SPAD is greater than the avalanche breakdown voltage, the avalanche will continue, and the SPAD cannot detect subsequent photons, and the continuous avalanche process will damage the SPAD device

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