IEEE Circuits and Systems Magazine - Q4 2020 - 16
Fig. 20 shows a MOSFET version of the gm-boosted
differential Colpitts VCO presented in [35]. [82] presents a similar circuit with gate-to-source feedback (GSColpitts), where a deeper analysis of that oscillator is
also presented. In this work, the effect of the capacitive
divider on the Colpitts behavior is discussed. In [58],
the bulk of the cross-coupled transistors are used to enhance the gain of the circuit as shown in Fig. 21. In order
to decrease the VDD the tail transistor is removed, thus
the circuit doesn't have any common mode behavior. On
the other hand, it reduces the effect of the flicker noise,
which is usually modulated to the resonance frequency
since the tail transistor acts as a mixer which up-converts this noise.
B. Complementary Common
Drain Colpitts Oscillator
In the previous section, we showed that a differential
common drain can be realized by connecting two single-ended oscillators back to back. To make a complementary version of the differential oscillator, one can
instead of connecting the single-ended oscillators back
to back, stack them. A PMOS single-ended oscillator can
be placed on top of a NMOS single-ended, as shown
in Fig. 22 and replace the two inductors with a single
one, connected between the two oscillators as shown in
Fig. 23 [83].
Similar approaches have earlier been proposed for
common gate Colpitts [84] and cross-coupled Oscillators [85], which will be presented later in this paper.
Fig. 24 shows the Small Signal Model (SSM) of the Complementary Differential Common Drain (CDCD) Colpitts
presented in Fig. 23. In the SSM we have kept the passive
components in order show that this circuit resembles
the Balanced Differential Common Drain (BDCD) Colpitts oscillator shown in Fig. 17.
In this configuration, the stacked capacitors add in
series and the resonance frequency is then given by:
ft =
2
(7)
L C1 C2
C1 + C2
2r
FBAR
MN1
i1
i2
MN1
i1
i2
Vout2
Vout1
MN2
MN1
MN2
C2
i3
MN3
Vbias2
i3 MN3
(a)
MN2
C3
C1
MN3
C4
MN4
Vbias2
(b)
Figure 19. Cross-coupled transistors are used to improve the
transconductance of the Colpitts oscillator. (a) shows the circuit implementation and (b) the circuits switching behaviour.
Figure 21. gm-boosted differential common drain Colpitts
topology [58].
Vbias
MP1
C1
L
MN1
Vout1
MN2
C1
C3
C3
MN3
Vout
C2
FBAR
MP2
Vout2
MN1
MN4
C1
Vout
L
Vbias
Figure 20. gm-boosted differential common drain Colpitts
topology [35], it is a combination of the differential Colpitts
shown in Fig. 18 and a cross-coupled pair.
16â
C2
MN5
Vbias
MN2
Figure 22. Schematics of the NMOS and PMOS single-ended common drain Colpitts oscillators.
IEEE CIRCUITS AND SYSTEMS MAGAZINE
FOURTH QUARTER 2020
IEEE Circuits and Systems Magazine - Q4 2020
Table of Contents for the Digital Edition of IEEE Circuits and Systems Magazine - Q4 2020
Contents
IEEE Circuits and Systems Magazine - Q4 2020 - Cover1
IEEE Circuits and Systems Magazine - Q4 2020 - Cover2
IEEE Circuits and Systems Magazine - Q4 2020 - Contents
IEEE Circuits and Systems Magazine - Q4 2020 - 2
IEEE Circuits and Systems Magazine - Q4 2020 - 3
IEEE Circuits and Systems Magazine - Q4 2020 - 4
IEEE Circuits and Systems Magazine - Q4 2020 - 5
IEEE Circuits and Systems Magazine - Q4 2020 - 6
IEEE Circuits and Systems Magazine - Q4 2020 - 7
IEEE Circuits and Systems Magazine - Q4 2020 - 8
IEEE Circuits and Systems Magazine - Q4 2020 - 9
IEEE Circuits and Systems Magazine - Q4 2020 - 10
IEEE Circuits and Systems Magazine - Q4 2020 - 11
IEEE Circuits and Systems Magazine - Q4 2020 - 12
IEEE Circuits and Systems Magazine - Q4 2020 - 13
IEEE Circuits and Systems Magazine - Q4 2020 - 14
IEEE Circuits and Systems Magazine - Q4 2020 - 15
IEEE Circuits and Systems Magazine - Q4 2020 - 16
IEEE Circuits and Systems Magazine - Q4 2020 - 17
IEEE Circuits and Systems Magazine - Q4 2020 - 18
IEEE Circuits and Systems Magazine - Q4 2020 - 19
IEEE Circuits and Systems Magazine - Q4 2020 - 20
IEEE Circuits and Systems Magazine - Q4 2020 - 21
IEEE Circuits and Systems Magazine - Q4 2020 - 22
IEEE Circuits and Systems Magazine - Q4 2020 - 23
IEEE Circuits and Systems Magazine - Q4 2020 - 24
IEEE Circuits and Systems Magazine - Q4 2020 - 25
IEEE Circuits and Systems Magazine - Q4 2020 - 26
IEEE Circuits and Systems Magazine - Q4 2020 - 27
IEEE Circuits and Systems Magazine - Q4 2020 - 28
IEEE Circuits and Systems Magazine - Q4 2020 - 29
IEEE Circuits and Systems Magazine - Q4 2020 - 30
IEEE Circuits and Systems Magazine - Q4 2020 - 31
IEEE Circuits and Systems Magazine - Q4 2020 - 32
IEEE Circuits and Systems Magazine - Q4 2020 - 33
IEEE Circuits and Systems Magazine - Q4 2020 - 34
IEEE Circuits and Systems Magazine - Q4 2020 - 35
IEEE Circuits and Systems Magazine - Q4 2020 - 36
IEEE Circuits and Systems Magazine - Q4 2020 - 37
IEEE Circuits and Systems Magazine - Q4 2020 - 38
IEEE Circuits and Systems Magazine - Q4 2020 - 39
IEEE Circuits and Systems Magazine - Q4 2020 - 40
IEEE Circuits and Systems Magazine - Q4 2020 - 41
IEEE Circuits and Systems Magazine - Q4 2020 - 42
IEEE Circuits and Systems Magazine - Q4 2020 - 43
IEEE Circuits and Systems Magazine - Q4 2020 - 44
IEEE Circuits and Systems Magazine - Q4 2020 - 45
IEEE Circuits and Systems Magazine - Q4 2020 - 46
IEEE Circuits and Systems Magazine - Q4 2020 - 47
IEEE Circuits and Systems Magazine - Q4 2020 - 48
IEEE Circuits and Systems Magazine - Q4 2020 - 49
IEEE Circuits and Systems Magazine - Q4 2020 - 50
IEEE Circuits and Systems Magazine - Q4 2020 - 51
IEEE Circuits and Systems Magazine - Q4 2020 - 52
IEEE Circuits and Systems Magazine - Q4 2020 - 53
IEEE Circuits and Systems Magazine - Q4 2020 - 54
IEEE Circuits and Systems Magazine - Q4 2020 - 55
IEEE Circuits and Systems Magazine - Q4 2020 - 56
IEEE Circuits and Systems Magazine - Q4 2020 - 57
IEEE Circuits and Systems Magazine - Q4 2020 - 58
IEEE Circuits and Systems Magazine - Q4 2020 - 59
IEEE Circuits and Systems Magazine - Q4 2020 - 60
IEEE Circuits and Systems Magazine - Q4 2020 - 61
IEEE Circuits and Systems Magazine - Q4 2020 - 62
IEEE Circuits and Systems Magazine - Q4 2020 - 63
IEEE Circuits and Systems Magazine - Q4 2020 - 64
IEEE Circuits and Systems Magazine - Q4 2020 - 65
IEEE Circuits and Systems Magazine - Q4 2020 - 66
IEEE Circuits and Systems Magazine - Q4 2020 - 67
IEEE Circuits and Systems Magazine - Q4 2020 - 68
IEEE Circuits and Systems Magazine - Q4 2020 - 69
IEEE Circuits and Systems Magazine - Q4 2020 - 70
IEEE Circuits and Systems Magazine - Q4 2020 - 71
IEEE Circuits and Systems Magazine - Q4 2020 - 72
IEEE Circuits and Systems Magazine - Q4 2020 - 73
IEEE Circuits and Systems Magazine - Q4 2020 - 74
IEEE Circuits and Systems Magazine - Q4 2020 - 75
IEEE Circuits and Systems Magazine - Q4 2020 - 76
IEEE Circuits and Systems Magazine - Q4 2020 - 77
IEEE Circuits and Systems Magazine - Q4 2020 - 78
IEEE Circuits and Systems Magazine - Q4 2020 - 79
IEEE Circuits and Systems Magazine - Q4 2020 - 80
IEEE Circuits and Systems Magazine - Q4 2020 - 81
IEEE Circuits and Systems Magazine - Q4 2020 - 82
IEEE Circuits and Systems Magazine - Q4 2020 - 83
IEEE Circuits and Systems Magazine - Q4 2020 - 84
IEEE Circuits and Systems Magazine - Q4 2020 - 85
IEEE Circuits and Systems Magazine - Q4 2020 - 86
IEEE Circuits and Systems Magazine - Q4 2020 - 87
IEEE Circuits and Systems Magazine - Q4 2020 - 88
IEEE Circuits and Systems Magazine - Q4 2020 - Cover3
IEEE Circuits and Systems Magazine - Q4 2020 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2023Q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2023Q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2023Q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2022Q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021Q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2021q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2020q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2019q1
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q4
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q3
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q2
https://www.nxtbook.com/nxtbooks/ieee/circuitsandsystems_2018q1
https://www.nxtbookmedia.com