IEEE Circuits and Systems Magazine - Q3 2018 - 43

Automotive
systems
Conversion efficiency
86%
200
SSPB
[112] A. D. Elliott and P. D.
Mitcheson

External supply

0.18 nm TSMC CMOS
area 0.3 mm2, package
0.25 cm3
Discrete components
Active diode, bias flip,
trickle charger
[111] E. E. Aktakka et al.

[110] S. Du et al.

13-155,
26-419

40

Diode bridge, SECE
with shared inductor
SSHI
[109] A. Romani et al.

82

60
[108] M. Dini, et al.

SECE, residual charge
inversion

Self-powered
Pin > 2.7 nW

0.35 nm CMOS -

Wearable
electronics

Conversion efficiency
50-74%
Externally powered
83%, self-powered
48%
Power extraction
efficiency 58-86%
Discrete components

Structural
monitoring
Consumer
electronics

Consumer
electronics
Consumer
electronics
Conversion efficiency
60%
Conversion efficiency
85.3%
0.25 nm HV CMOS n.a.
123-132
[107] C. Chen, et al.

S-SSHI

Self-powered
Pin > 12 nW
Self-powered
Pin > 296 nW
Vin > 0.5 V
Self-powered
Vin > 1.5 V
Self or externally
powered Pin > 776.6 nW

0.32 nm CMOS area
0.95 mm2

Possible Target
Application
Efficiency
Process and Chip-Area
Start-Up Requirements
Frequency
(Hz)
Architecture
Reference

Table IV.
Comparison of the selected state-of-the-art piezoelectric harvesting circuits. (Continued)

THIRD quaRTeR 2018

convert the rectified voltage according to the target application voltage requirement [101].
The disadvantage in using this conventional approach,
as shown in Fig. 21, is that the energy goes through an
additional conversion stage, reducing the conversion
efficiency and increasing the chip area. An alternative
solution that attempts to address this problem can be
found in [101] where an Energy Aware Interface (EAI)
is implemented.
MPPT algorithms have been successfully employed
in photovoltaic applications in which the load matching
is purely resistive. The impedance nature of piezoelectric micro-generators is mainly capacitive. One implementation example, in which a two dimensional MPPT
algorithm considering both the reactive and resistive
components is implemented, can be found in [102]. The
drawback in using this approach is the need for high
power and voltage levels to implement the complex
control scheme. There is a trade-off between control
scheme (and thus efficiency) and power consumption. Complex MPPT algorithms (usually implemented
on microprocessors as proposed in [102]) can highly
increase the overall conversion efficiency if the input
power levels are relatively high (mW range). If a piezoelectric transducer provides input power levels of the
order of tens of µW, custom IC designs of simplified
MPPT control schemes might be the best implementation choice.
A MPPT control algorithm has also been applied to
SSHI rectifiers, resulting in a mixed approach. An implementation of such a hybrid approach can be found in [89].
Different types of MPPT control schemes have been
implemented in piezoelectric energy harvesting systems. An implementation of fractional VOC MPPT control
scheme can be found in [48], while in [46] the perturb
and observe (P&O) algorithm is used. A variation of a
P&O algorithm with a variable step size can be found
in [103] while, the downhill simplex method was implemented in [102]. Other works propose a custom MPPT
scheme integrated in the design, two examples are [47],
in which the MPPT mechanism is based on a time-multiplexing scheme, and [90] in which a MPPT algorithm
is implemented using a high-pass filter, the derivative
operator, and a comparator.
V. PEH Performance Discussion
Table IV summarizes some of the state-of-the-art piezoelectric energy harvesting rectifiers. Most of the proposed architectures are either resonant rectifiers [43],
[75], [104], [105], [107]-[110], [112] or MPPT-based implementations [44], [46]-[48], [91], [101], [113]. In addition,
other architectures have been proposed to efficiently
scavenge energy [49], [50], [63], [86], [100], [106], [111].
Ieee cIRcuITs anD sysTems magazIne

43



Table of Contents for the Digital Edition of IEEE Circuits and Systems Magazine - Q3 2018

Contents
IEEE Circuits and Systems Magazine - Q3 2018 - Cover1
IEEE Circuits and Systems Magazine - Q3 2018 - Cover2
IEEE Circuits and Systems Magazine - Q3 2018 - Contents
IEEE Circuits and Systems Magazine - Q3 2018 - 2
IEEE Circuits and Systems Magazine - Q3 2018 - 3
IEEE Circuits and Systems Magazine - Q3 2018 - 4
IEEE Circuits and Systems Magazine - Q3 2018 - 5
IEEE Circuits and Systems Magazine - Q3 2018 - 6
IEEE Circuits and Systems Magazine - Q3 2018 - 7
IEEE Circuits and Systems Magazine - Q3 2018 - 8
IEEE Circuits and Systems Magazine - Q3 2018 - 9
IEEE Circuits and Systems Magazine - Q3 2018 - 10
IEEE Circuits and Systems Magazine - Q3 2018 - 11
IEEE Circuits and Systems Magazine - Q3 2018 - 12
IEEE Circuits and Systems Magazine - Q3 2018 - 13
IEEE Circuits and Systems Magazine - Q3 2018 - 14
IEEE Circuits and Systems Magazine - Q3 2018 - 15
IEEE Circuits and Systems Magazine - Q3 2018 - 16
IEEE Circuits and Systems Magazine - Q3 2018 - 17
IEEE Circuits and Systems Magazine - Q3 2018 - 18
IEEE Circuits and Systems Magazine - Q3 2018 - 19
IEEE Circuits and Systems Magazine - Q3 2018 - 20
IEEE Circuits and Systems Magazine - Q3 2018 - 21
IEEE Circuits and Systems Magazine - Q3 2018 - 22
IEEE Circuits and Systems Magazine - Q3 2018 - 23
IEEE Circuits and Systems Magazine - Q3 2018 - 24
IEEE Circuits and Systems Magazine - Q3 2018 - 25
IEEE Circuits and Systems Magazine - Q3 2018 - 26
IEEE Circuits and Systems Magazine - Q3 2018 - 27
IEEE Circuits and Systems Magazine - Q3 2018 - 28
IEEE Circuits and Systems Magazine - Q3 2018 - 29
IEEE Circuits and Systems Magazine - Q3 2018 - 30
IEEE Circuits and Systems Magazine - Q3 2018 - 31
IEEE Circuits and Systems Magazine - Q3 2018 - 32
IEEE Circuits and Systems Magazine - Q3 2018 - 33
IEEE Circuits and Systems Magazine - Q3 2018 - 34
IEEE Circuits and Systems Magazine - Q3 2018 - 35
IEEE Circuits and Systems Magazine - Q3 2018 - 36
IEEE Circuits and Systems Magazine - Q3 2018 - 37
IEEE Circuits and Systems Magazine - Q3 2018 - 38
IEEE Circuits and Systems Magazine - Q3 2018 - 39
IEEE Circuits and Systems Magazine - Q3 2018 - 40
IEEE Circuits and Systems Magazine - Q3 2018 - 41
IEEE Circuits and Systems Magazine - Q3 2018 - 42
IEEE Circuits and Systems Magazine - Q3 2018 - 43
IEEE Circuits and Systems Magazine - Q3 2018 - 44
IEEE Circuits and Systems Magazine - Q3 2018 - 45
IEEE Circuits and Systems Magazine - Q3 2018 - 46
IEEE Circuits and Systems Magazine - Q3 2018 - 47
IEEE Circuits and Systems Magazine - Q3 2018 - 48
IEEE Circuits and Systems Magazine - Q3 2018 - Cover3
IEEE Circuits and Systems Magazine - Q3 2018 - 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