IEEE Solid-States Circuits Magazine - Summer 2018 - 30

VS

VS

Thin Oxide

Thin Oxide

Vout

Vout
Va
Vref

VBQ

Vin

Vclamp - VTH

Va

Va

Vin

Vclamp

VBQ

Thick Oxide

Thick Oxide

Figure 7: The common level-translation schemes for SPAD front ends.

line in a small ring oscillator and
count the periods between the START
and STOP signals as in Figure 9. Very
compact TDCs and resolutions ranging from 200 down to 50 ps can be

achieved with interpolation techniques [6], [7].
However, digital counters can employ a relatively large area and typically the ring oscillator period cannot

be tuned in a wide range. So there is
some room also for the analog solution (i.e., the TAC) that mainly relies
on charging a capacitor with a constant current between the START and
STOP signals (Figure 10). Elaborated
solutions have been implemented
with current steering techniques to
speed up the initial transient and redundancy to cope with the unavoidable nonidealities of analog circuits,
such as nonuniformity [8].
When SPAD-based imaging sensors contain a large number of pixels,
realizing a TCSPC measurement may
become difficult at the system level,
where a bottleneck can be encountered in the amount of generated
data; indeed, keeping a histogram per
pixel may require both a high transfer bandwidth and a large memory.
Sometimes, it is possible to exploit
some prior knowledge of the event to
be recorded, and, sometimes, it is not
necessary to acquire a fine histogram
but just to count the number of events
that fall within one or more specified

Front End

Figure 8: The principle of operation of a TCSPC measurement.

Start
Stop

Td

Td

Td

Start

T

T

T

Stop
Inv 1
Inv 2
TDC [0:N ] Inv 3
TDC
Σ

9

RES

Figure 9: The ring-oscillator-based TDC operating principle, suitable for compact stopwatches for in-pixel timestamping.

Ibp

VTAC
RES

Event

Event

Event

VTAC
RES

(a)

(b)

Ibn

VTAC

Ibp

T1

T2

V1

V2

(c)

Figure 10: The (a) principle of operation, (b) actual implementation [8] of a TAC, and (c) a graph of both. The reset signal (RES) clears the
capacitor, while the length of the pulse applied to the event input is measured integrating the current.

30

su m m e r 2 0 18

IEEE SOLID-STATE CIRCUITS MAGAZINE



IEEE Solid-States Circuits Magazine - Summer 2018

Table of Contents for the Digital Edition of IEEE Solid-States Circuits Magazine - Summer 2018

Contents
IEEE Solid-States Circuits Magazine - Summer 2018 - Cover1
IEEE Solid-States Circuits Magazine - Summer 2018 - Cover2
IEEE Solid-States Circuits Magazine - Summer 2018 - Contents
IEEE Solid-States Circuits Magazine - Summer 2018 - 2
IEEE Solid-States Circuits Magazine - Summer 2018 - 3
IEEE Solid-States Circuits Magazine - Summer 2018 - 4
IEEE Solid-States Circuits Magazine - Summer 2018 - 5
IEEE Solid-States Circuits Magazine - Summer 2018 - 6
IEEE Solid-States Circuits Magazine - Summer 2018 - 7
IEEE Solid-States Circuits Magazine - Summer 2018 - 8
IEEE Solid-States Circuits Magazine - Summer 2018 - 9
IEEE Solid-States Circuits Magazine - Summer 2018 - 10
IEEE Solid-States Circuits Magazine - Summer 2018 - 11
IEEE Solid-States Circuits Magazine - Summer 2018 - 12
IEEE Solid-States Circuits Magazine - Summer 2018 - 13
IEEE Solid-States Circuits Magazine - Summer 2018 - 14
IEEE Solid-States Circuits Magazine - Summer 2018 - 15
IEEE Solid-States Circuits Magazine - Summer 2018 - 16
IEEE Solid-States Circuits Magazine - Summer 2018 - 17
IEEE Solid-States Circuits Magazine - Summer 2018 - 18
IEEE Solid-States Circuits Magazine - Summer 2018 - 19
IEEE Solid-States Circuits Magazine - Summer 2018 - 20
IEEE Solid-States Circuits Magazine - Summer 2018 - 21
IEEE Solid-States Circuits Magazine - Summer 2018 - 22
IEEE Solid-States Circuits Magazine - Summer 2018 - 23
IEEE Solid-States Circuits Magazine - Summer 2018 - 24
IEEE Solid-States Circuits Magazine - Summer 2018 - 25
IEEE Solid-States Circuits Magazine - Summer 2018 - 26
IEEE Solid-States Circuits Magazine - Summer 2018 - 27
IEEE Solid-States Circuits Magazine - Summer 2018 - 28
IEEE Solid-States Circuits Magazine - Summer 2018 - 29
IEEE Solid-States Circuits Magazine - Summer 2018 - 30
IEEE Solid-States Circuits Magazine - Summer 2018 - 31
IEEE Solid-States Circuits Magazine - Summer 2018 - 32
IEEE Solid-States Circuits Magazine - Summer 2018 - 33
IEEE Solid-States Circuits Magazine - Summer 2018 - 34
IEEE Solid-States Circuits Magazine - Summer 2018 - 35
IEEE Solid-States Circuits Magazine - Summer 2018 - 36
IEEE Solid-States Circuits Magazine - Summer 2018 - 37
IEEE Solid-States Circuits Magazine - Summer 2018 - 38
IEEE Solid-States Circuits Magazine - Summer 2018 - 39
IEEE Solid-States Circuits Magazine - Summer 2018 - 40
IEEE Solid-States Circuits Magazine - Summer 2018 - 41
IEEE Solid-States Circuits Magazine - Summer 2018 - 42
IEEE Solid-States Circuits Magazine - Summer 2018 - 43
IEEE Solid-States Circuits Magazine - Summer 2018 - 44
IEEE Solid-States Circuits Magazine - Summer 2018 - 45
IEEE Solid-States Circuits Magazine - Summer 2018 - 46
IEEE Solid-States Circuits Magazine - Summer 2018 - 47
IEEE Solid-States Circuits Magazine - Summer 2018 - 48
IEEE Solid-States Circuits Magazine - Summer 2018 - 49
IEEE Solid-States Circuits Magazine - Summer 2018 - 50
IEEE Solid-States Circuits Magazine - Summer 2018 - 51
IEEE Solid-States Circuits Magazine - Summer 2018 - 52
IEEE Solid-States Circuits Magazine - Summer 2018 - 53
IEEE Solid-States Circuits Magazine - Summer 2018 - 54
IEEE Solid-States Circuits Magazine - Summer 2018 - 55
IEEE Solid-States Circuits Magazine - Summer 2018 - 56
IEEE Solid-States Circuits Magazine - Summer 2018 - 57
IEEE Solid-States Circuits Magazine - Summer 2018 - 58
IEEE Solid-States Circuits Magazine - Summer 2018 - 59
IEEE Solid-States Circuits Magazine - Summer 2018 - 60
IEEE Solid-States Circuits Magazine - Summer 2018 - 61
IEEE Solid-States Circuits Magazine - Summer 2018 - 62
IEEE Solid-States Circuits Magazine - Summer 2018 - 63
IEEE Solid-States Circuits Magazine - Summer 2018 - 64
IEEE Solid-States Circuits Magazine - Summer 2018 - 65
IEEE Solid-States Circuits Magazine - Summer 2018 - 66
IEEE Solid-States Circuits Magazine - Summer 2018 - 67
IEEE Solid-States Circuits Magazine - Summer 2018 - 68
IEEE Solid-States Circuits Magazine - Summer 2018 - 69
IEEE Solid-States Circuits Magazine - Summer 2018 - 70
IEEE Solid-States Circuits Magazine - Summer 2018 - 71
IEEE Solid-States Circuits Magazine - Summer 2018 - 72
IEEE Solid-States Circuits Magazine - Summer 2018 - 73
IEEE Solid-States Circuits Magazine - Summer 2018 - 74
IEEE Solid-States Circuits Magazine - Summer 2018 - 75
IEEE Solid-States Circuits Magazine - Summer 2018 - 76
IEEE Solid-States Circuits Magazine - Summer 2018 - 77
IEEE Solid-States Circuits Magazine - Summer 2018 - 78
IEEE Solid-States Circuits Magazine - Summer 2018 - 79
IEEE Solid-States Circuits Magazine - Summer 2018 - 80
IEEE Solid-States Circuits Magazine - Summer 2018 - 81
IEEE Solid-States Circuits Magazine - Summer 2018 - 82
IEEE Solid-States Circuits Magazine - Summer 2018 - 83
IEEE Solid-States Circuits Magazine - Summer 2018 - 84
IEEE Solid-States Circuits Magazine - Summer 2018 - 85
IEEE Solid-States Circuits Magazine - Summer 2018 - 86
IEEE Solid-States Circuits Magazine - Summer 2018 - 87
IEEE Solid-States Circuits Magazine - Summer 2018 - 88
IEEE Solid-States Circuits Magazine - Summer 2018 - 89
IEEE Solid-States Circuits Magazine - Summer 2018 - 90
IEEE Solid-States Circuits Magazine - Summer 2018 - 91
IEEE Solid-States Circuits Magazine - Summer 2018 - 92
IEEE Solid-States Circuits Magazine - Summer 2018 - 93
IEEE Solid-States Circuits Magazine - Summer 2018 - 94
IEEE Solid-States Circuits Magazine - Summer 2018 - 95
IEEE Solid-States Circuits Magazine - Summer 2018 - 96
IEEE Solid-States Circuits Magazine - Summer 2018 - 97
IEEE Solid-States Circuits Magazine - Summer 2018 - 98
IEEE Solid-States Circuits Magazine - Summer 2018 - 99
IEEE Solid-States Circuits Magazine - Summer 2018 - 100
IEEE Solid-States Circuits Magazine - Summer 2018 - 101
IEEE Solid-States Circuits Magazine - Summer 2018 - 102
IEEE Solid-States Circuits Magazine - Summer 2018 - 103
IEEE Solid-States Circuits Magazine - Summer 2018 - 104
IEEE Solid-States Circuits Magazine - Summer 2018 - 105
IEEE Solid-States Circuits Magazine - Summer 2018 - 106
IEEE Solid-States Circuits Magazine - Summer 2018 - 107
IEEE Solid-States Circuits Magazine - Summer 2018 - 108
IEEE Solid-States Circuits Magazine - Summer 2018 - Cover3
IEEE Solid-States Circuits Magazine - Summer 2018 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2019
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2019
https://www.nxtbook.com/nxtbooks/ieee/mssc_2019summer
https://www.nxtbook.com/nxtbooks/ieee/mssc_2019winter
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018fall
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018summer
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018spring
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018winter
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2014
https://www.nxtbookmedia.com