Analog Devices MAX30001G Manual page 22

MAX30001G Evaluation Kit
Galvanic Skin Response Measurement
When using the BioZ channel for GSR measurements, two dry electrodes should be used to focus the measurement on
the skin's contact impedance. A lower current generator frequency, such as 125Hz, 250Hz, or 500Hz should be selected.
Ensure that the BioZ receiver's analog high pass filter cutoff frequency is set below this stimulus frequency. At these
lower frequencies, a 220nF DC blocking capacitor should be used between both DRVP and DRVN and their respective
electrode. GSR impedance measurements are typically as high as 1MΩ but maybe as high as 10MΩ under low-moisture
conditions. Choose lower current generator amplitudes so that the differential voltage at the BioZ input channel does
not exceed the maximum AC input differential range of ±90 mV. Figure 19 illustrates the setup for GSR measurements.
ECGP
ECGN
BIP
BIN
DRVP
DRVN
Figure 19. Configuring the EV Kit to measure GSR.
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EP_UNBAL
0Ω
EP_EN
0Ω
EN_UNBAL
0Ω RP
BP_BN 100Ω
0Ω
RN
220nF
220nF
Evaluates: MAX30001G
J_ECGP
J_ECGN
EP_BP EN_BN
J_BIP
J_BIN
DP_BP DN_BN
J_DRVP
J_DRVN
ECGP
ECGN
BIP
BIN
DRVP
DRVN
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