Abstract
Fast active quenching of single-photon avalanche diodes (SPADs) is important to reduce the afterpulsing probability (APP). An option to reduce the reaction time of electronics to a SPAD's avalanche is to design a quencher exploiting bipolar transistors. A quencher in a 0.35 μm CMOS technology with a nominal supply voltage of 3.3 V, which operated with excess bias voltages up to 6.6 V, was re-designed accordingly. In the new 0.35 μm pure-silicon BiCMOS quencher, the comparator takes advantage of a bipolar differential amplifier, which additionally gives the head room to increase the width of some CMOS transistors as well. The proposed BiCMOS quencher is able to drive the load of a wire-bonded 184 μm-diameter SPAD, while the CMOS design fails. A comparison, where both chips are measured with a wire-bonded, 34 μm-diameter SPAD, shows that the BiCMOS quencher has a reaction time, which is 330 ps to 1.1 ns faster than that of the CMOS quencher.
Highlights
Atechnique widely used to detect single photons is to operate an avalanche photodiode (APD) with a reverse voltage above breakdown in the so-called Geiger mode [1]
For comparison separate Single Photon Avalanche Diode (SPAD) of the same type were bonded to each quencher chip, where both were glued and bonded to a printed circuit board (PCB)
The crossing point is at the voltage level, where active quenching of the BiCMOS quencher after its reaction time starts at the end of the initial discharge of the SPAD
Summary
Atechnique widely used to detect single photons is to operate an avalanche photodiode (APD) with a reverse voltage above breakdown in the so-called Geiger mode [1]. Without high-voltage transistors, in [29] an excess bias of 13.2V was achieved in 3.3V/0.35μm CMOS technology with the help of a quadruple-voltage quenching/resetting switch for a thick SPAD with 40μm active diameter, which was integrated on the same chip. In this paper the reduction of the time for initial passive discharge of the SPAD’s cathode until active quenching starts for an active quencher in 0.35μm/3.3V CMOS technology (published in [33]) will be shown, if npn bipolar transistors, that are provided in the same technology, are used To do this we designed a BiCMOS active quenching circuit with a bipolar differential amplifier and compared it with the original CMOS quencher by transient measurements at the cathode of the SPADs, which were wire-bonded to the chips. This shortens the reset time of the SPAD and gives the capability of the quencher to work with SPADs having a larger area
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
