Design of current sources for load common mode optimization

Vinicius G Sirtoli; Kaue F Morcelles; Volney C Vincence

Open Access

Design of current sources for load common mode optimization

Vinicius G Sirtoli

Kaue F Morcelles

and

Volney C Vincence

| Dec 19, 2018

Journal of Electrical Bioimpedance

Volume 9 (2018): Issue 1 (January 2018)

About this article

Cite

Published Online: Dec 19, 2018

Page range: 59 - 71

Received: May 15, 2018

DOI: https://doi.org/10.2478/joeb-2018-0011

Keywords
Bioimpedance, Howland current source, Common mode rejection

© 2018 Vinicius G. Sirtoli, Kaue F. Morcelles, Volney C. Vincence published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Enhanced Howland Current Source with Bridge topology (BRIDGE-1)

Enhanced Howland Current Source with differential amplifier (EHCS–DIF).

Enhanced Howland Current Source with Bridge topology (BRIDGE-2).

Mirrored Enhanced Howland Current Source (MEHCS).

Mirrored Enhanced Howland Current Source with differential amplifiers (MEHCS- DIF).

Quad-Feedback Enhanced Howland Current Source with differential amplifiers (QUAD).

Crossed Differential Enhanced Howland Current Source with differential amplifiers (DIF_C).

Modified Differential Enhanced Howland Current Source with differential amplifiers (DIF_M).

Simulated output current when the value of R3 is changed. The value of R3 in ohms is showed at the legends, the load was 1 kΩ. a) QUAD b) DIF_C c) DIF_M.

Simulated output impedance when the value of R3 is changed. The value of R3 in ohms is showed at the legends. a) QUAD b) DIF_C c) DIF_M.

Simulated and calculated output current for 1 Ω load. a) QUAD b) DIF_C using inverting input c) DIF_C using non-inverting input d) DIF_M.

Simulated and calculated output impedance. a) QUAD b) DIF_C c) DIF_M

Simulated common mode load voltage (VLcm) of the non-differential EHCS for a load of 1 kΩ.

Simulated common mode load voltage (VLcm) of the non-differential EHCS in time domain at 1 MHz for a load of 1 kΩ.

Simulated common mode load voltage (VLcm) of the non-differential EHCS for four different loads. The values shown in the legend are the value of the loads in Ω. a) EHCS-DIF b) BRIDGE-1 c) BRIDGE-2.

Simulated AC common mode load voltage (VLcm) of the mirrored group and proposed group. MEHCS-DIF and MEHCS have the same curve.

Simulated common mode load voltage (VLcm) of the mirrored group and proposed group at time domain in 1 MHz.

Simulated AC common mode load voltage (VLcm) of the mirrored group and proposed group, with unmatched control resistors (r and rx).

Simulated common mode load voltage (VLcm) of the mirrored group and proposed group at time domain in 1 MHz with unmatched control resistors (r and rx).

Simulated common mode load voltage (VLcm) of the proposed group, with unmatched (± 1%) control resistors (r and rx), for four different loads. The label shows the values of the loads in Ω. a) QUAD b) DIF_C c) DIF_M.

Common mode voltage distribution using Monte Carlo simulation considering resistors with 1% tolerance.

Measured output current for different loads (100, 995, 2492 and 4692 Ω). a) QUAD b) DIF_C c) DIF_M.

Measured and simulated output current phase for a 1 kΩ load. a) QUAD b) DIF_C c) DIF_M.

Measured output impedance. a) QUAD b) DIF_C c) DIF_M

Measured load common mode voltage. a) QUAD b) DIF_C c) DIF_M

Measured common mode rejection ratio (CMRR). a) QUAD b) DIF_C c) DIF_M

Measured values of Zload.max

QUAD [kΩ]	DIF_C [kΩ]	DIF_M [kΩ]
6.31	5.33	5.16

Calculated and simulated values of Zload.max when varying R3

Circuit	Z_load_max[kΩ]	R₃= r_x	R₃=4.7k	R₃=10k
QUAD r_x =500 Ω	Simulated	3.6	6.1	6.6
QUAD r_x =500 Ω	Calculated	3.3	6.0	6.3
DIF_C r_x𝑟𝑥=1000 Ω	Simulated	3.1	5.1	5.6
DIF_C r_x𝑟𝑥=1000 Ω	Calculated	2.8	4.6	5.1
DIF_M r_x𝑟𝑥=1000 Ω	Simulated	4.6	5.6	5.6
DIF_M r_x𝑟𝑥=1000 Ω	Calculated	4.2	5.1	5.4

eISSN:: 1891-5469
Language:: English

Publication timeframe:: Volume Open
Journal Subjects:: Engineering, Bioengineering and Biomedical Engineering, Biomedical Electronics, Life Sciences, Biophysics, Medicine, Biomedical Engineering, Physics, Spectroscopy and Metrology

Journal RSS Feed

Design of current sources for load common mode optimization

Article Category: Research articles

Published Online: Dec 19, 2018

Page range: 59 - 71

Received: May 15, 2018

DOI: https://doi.org/10.2478/joeb-2018-0011

Keywords
Bioimpedance, Howland current source, Common mode rejection

© 2018 Vinicius G. Sirtoli, Kaue F. Morcelles, Volney C. Vincence published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig.1

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

Fig.12

Fig.13

Fig.14

Fig.15

Fig.16

Fig.17

Fig.18

Fig.19

Fig.20

Fig.21

Fig. 22

Fig.23

Fig.24

Fig.25

Fig.26

Fig.27

Measured values of Zload.max

Calculated and simulated values of Zload.max when varying R3

Design of current sources for load common mode optimization

Article Category: Research articles

Published Online: Dec 19, 2018

Page range: 59 - 71

Received: May 15, 2018

DOI: https://doi.org/10.2478/joeb-2018-0011

KeywordsBioimpedance, Howland current source, Common mode rejection

© 2018 Vinicius G. Sirtoli, Kaue F. Morcelles, Volney C. Vincence published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig.1

Fig.2

Fig.3

Fig.4

Fig.5

Fig.6

Fig.7

Fig.8

Fig.9

Fig.10

Fig.11

Fig.12

Fig.13

Fig.14

Fig.15

Fig.16

Fig.17

Fig.18

Fig.19

Fig.20

Fig.21

Fig. 22

Fig.23

Fig.24

Fig.25

Fig.26

Fig.27

Measured values of Zload.max

Calculated and simulated values of Zload.max when varying R3

Keywords
Bioimpedance, Howland current source, Common mode rejection