Input Voltage for High-Impedance Conditions with AC Lead-Off Detection
Explore the relationship between electrode impedance and input voltage under high-impedance and open-circuit conditions using ADS129X technology. This study delves into the impact of various impedances on voltage waveforms generated by AC lead-off detection methods. Dive into the nuances of lead-off resistor pull-up/pull-down configurations for DC lead-off detection. Discover insights shared by Ryan Andrews regarding this intricate topic.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
ADS129X: V_LOFF VS. R_ELEC Understanding input voltage for high-impedance and open-circuit conditions with AC lead-off detection Ryan Andrews 1 TI Confidential NDA Restrictions
TINA schematic Use this side only for DC lead-off resistor pull-up/pull-down method Set LOFF_SENSx: GND = 0 VLOFF = 1 Configure analog supply voltages. Vcc Select DC or AC lead-off current source. RLDREF AVDD 3.3 VLOFF VLOFF Vcc Vcc + + + + R6 10MEG AC_LOFF VCVS1 500m DC_LOFF 24u + - - Configure magnitude and frequency lead-off current sources. - AVSS 0 VCCS1 1 Vee SW-SPDT5 Vee + A Vcc Objective: sweep electrode impedance from nominal to open- circuit and observe voltage waveform produced by AC lead- off current R3 4.99k U2 OPA350 7 3 ++ I_LOFFP 6 2 C1 4.7n - 4 + R4 1MEG V_CINP Vee Vee - VLOFF Vee R1 220k + VCCS2 -1 A I_CIN R7 10MEG + RLDREF - R2 220k + R8 1MEG V_DIFF - Vee + 4 2 A - 6 R5 4.99k ++ 7 3 U3 OPA350 I_LOFFN + Vcc C3 4.7n V_CINN - R51 1MEG RLDREF C2 1.5n Vee RLDOUT 4 2 - + 6 A + 3 + I_RLD U4 OPA350 7 RLDREF Vcc 2 TI Confidential NDA Restrictions
Electrode impedance: 1k 24.00n AC_LOFF -24.00n 43.06n I_CIN -43.06n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n 150.90u V_CINN -149.62u 150.92u V_CINP -149.60u 300.54u V_DIFF -300.50u 150.00m 175.00m 200.00m Time (s) 3 TI Confidential NDA Restrictions
Electrode impedance: 10k 24.00n AC_LOFF -24.00n 44.19n I_CIN -44.19n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n 367.73u V_CINN -366.49u 367.78u V_CINP -366.44u 734.27u V_DIFF -734.17u 150.00m 175.00m 200.00m Time (s) 4 TI Confidential NDA Restrictions
Electrode impedance: 100k 24.00n AC_LOFF -24.00n 46.96n I_CIN -46.96n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n 2.53m V_CINN -2.53m 2.54m V_CINP -2.53m 5.07m V_DIFF -5.07m 150.00m 175.00m 200.00m Time (s) 5 TI Confidential NDA Restrictions
Electrode impedance: 1M 24.00n AC_LOFF -24.00n 40.42n I_CIN -40.42n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n 16.53m V_CINN -16.54m 16.54m V_CINP -16.53m 33.07m V_DIFF -33.07m 150.00m 175.00m 200.00m Time (s) 6 TI Confidential NDA Restrictions
Electrode impedance: 10M 24.00n AC_LOFF -24.00n 25.97n I_CIN -26.08n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n 19.91m V_CINN -21.10m 21.09m V_CINP -19.92m 42.19m V_DIFF -39.84m 150.00m 175.00m 200.00m Time (s) 7 TI Confidential NDA Restrictions
Electrode impedance: 100M 24.00n AC_LOFF -24.00n 24.05n I_CIN -24.33n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n 6.58m V_CINN -35.28m 35.15m V_CINP -6.71m 70.42m V_DIFF -13.30m 150.00m 175.00m 200.00m Time (s) 8 TI Confidential NDA Restrictions
Electrode impedance: 1G 24.00n AC_LOFF -24.00n 23.98n I_CIN -24.02n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n -1.47m V_CINN -42.30m 41.01m V_CINP 180.14u 83.32m V_DIFF 1.65m 150.00m 175.00m 200.00m Time (s) 9 TI Confidential NDA Restrictions
Electrode impedance: 1T 24.00n AC_LOFF -24.00n 23.98n I_CIN -23.98n 24.00n I_LOFFN -24.00n 24.00n I_LOFFP -24.00n -259.40m V_CINN -300.08m 240.29m V_CINP 199.62m 540.36m V_DIFF 459.03m 150.00m 175.00m 200.00m Time (s) 10 TI Confidential NDA Restrictions
