A 2-GHz Bandwidth, Integrated Transimpedance Amplifier for Single-Photon Timing Applications

Abstract

In recent years, single-photon timing techniques have been employed in a steadily increasing number of applications. Most of these applications require high detector performance in terms of noise, photon detection efficiency, time resolution, and number of pixels operating in parallel. The detectors best fitting these requirements are single-photon avalanche diode (SPAD) arrays built in custom technology, although the systems based on such detectors are limited to a few pixels. In this paper, we present a novel read-out circuit, developed in a 0.18-μm high voltage-CMOS technology, for the detection of the SPAD avalanche current: the designed circuit is based on a 2.2-GHz bandwidth integrated transimpedance amplifier, followed by a low-pass filter, to reduce crosstalk, and by an integrated comparator. The pick-up circuit has a total power dissipation of 1.1 mW, occupies an overall area of 15,500 μm² and shows a time resolution down to 48 ps and a negligible crosstalk between two different pixels. All these features can open the way to the development of large SPAD arrays, characterized by a performance comparable with that of the single-pixel structures. Moreover, the good agreement between the simulated and the measured resolution (with a 14% maximum error) makes the future improvement of the evaluated performance possible

32ps timing jitter with a fully integrated front end circuit and single photon avalanche diodes

“…2. This circuit has been completely redesigned with respect to [8], since its noise was proved to be one of the main contributions to the overall performance of the stage. In particular, low voltage MOSFETs have been exploited.…”

“…Crotti et al in 2013 developed an avalanche current read‐out circuit suitable to be used with SPAD arrays [7]; nevertheless, this solution is based on discrete components and it is not suitable to be extended to densely integrated systems. The same authors in 2015 presented a fully integrated version of the avalanche read out circuit [8]; the circuit can provide the timing information with a jitter down to 48 ps and a negligible electrical crosstalk among two adjacent detectors. In this Letter, we present a new fully integrated avalanche current read out circuit able to extract the timing information from custom technology SPAD detectors with a timing jitter as low as 32 ps.…”

“…This made it possible to select the best value for V DD,TIA during the experimental measurements, as explained in the next section. Compared with [8], there is no capacitance in parallel to R 3 in the output stage: in fact, the pole introduced by the combination of R3 and the stray input capacitance of the comparator proved to be sufficient to filter out the crosstalk that may occur in SPAD arrays because of the operation of the active quenching circuit. When a quenching-reset transition is applied to one of the SPADs of an array, indeed, some current can flow towards the adjacent detectors causing crosstalk; however, since the rising edge of this spurious signals is typically faster than the avalanche current signal, a low-pass filtering action at the output of the read out circuit can be successfully applied to reduce this issue [7].…”

Silicon technologies for arrays of Single Photon Avalanche Diodes

“…not integrated on the same chip of the detector). This solution is based on a front-end circuit considerably different from the one represented in Figure 2.a and based on a transimpedance amplifier [36], [37] . However, also this solution requires a full isolation of the pixels as the AQC and the avalanche readout circuit are connected at the opposite terminals of the active junction.…”

High-performance timing electronics for single photon avalanche diode arrays

“…Unfortunately, not even this solution is appropriate for a dense array of detectors, since it would lead to a high power dissipation and low fill factor of the detectors. For these reasons a novel idea of pick-up circuit has been conceived [12] : instead of a high-impedance read-out circuit, the proposed circuit is aimed at the collection of all the charge that flows across the detector when an avalanche is triggered. In fact, it has been demonstrated [13] that remarkable results can be achieved if the pick-up circuit collects all the avalanche current: in this way the anode of the detector is kept at a fixed voltage and the electrical coupling via the common substrate is avoided.…”