ADS1298RECG-FE Input Signals
37
SBAU181B – March 2011 – Revised Janurary 2016
Copyright © 2011–2016, Texas Instruments Incorporated
ADS1298R
4.4
Normal Electrode Input
The
Normal Electrode
input on the MUX routes the inputs (VINP and VINN) differentially to the internal
PGA, as
illustrates. In this mode, an ECG, sine wave, or pulse generator may be connected to
test the ADS1298R.
shows a typical six-lead output when connected to a 5mV
PEAK
, 80BPM ECG signal.
Figure 34. Normal Electrode ECG Connection in ECG Display Tab
4.4.1
Capturing 12-Lead ECG Signals
To capture signals from external inputs:
1. Configure the
Channel Input
control in
Globally Set Channels
to
Normal Electrode
.
2. Connect the 10 ECG electrodes from the Fluke simulator to the EVM through the DB15 connector (J1).
Refer to
for the ECG cable details. The ECG electrode signals are passed through a single
pole RC filter followed by the lead configuration. For ECG signal processing, the electrode signals are
routed through J5 to the ADS1298R input. The signal path in the board can be chosen by jumper
settings, depending on the application.
4.5
MV
DD
Input, RLD Measurement, RLD Positive Electrode Driver, and RLD Negative
Electrode Driver
The MV
DD
input option allows the measurement of the supply voltage V
S
= (AV
DD
+ AV
SS
)/2 for channels 1,
2, 5, 6, 7, and 8; however, the supply voltage for channel 3 will be DV
DD
/2. As an example, in bipolar
supply mode, AV
DD
= 3.0V and AV
SS
= –2.5V. Therefore, with the PGA gain = 1, the output voltage
measured by the ADC will be approximately 0.25V.
The RLD measurement takes the voltage at the RLDIN pin and measures it on the PGA with respect to
(AV
DD
+ AV
SS
)/2. This feature is beneficial if the user would like to optimize the gain of the RLD loop.
