Datasheet

Data Sheet ADAS1000/ADAS1000-1/ADAS1000-2
Rev. A | Page 33 of 80
DEFIBRILLATOR PROTECTION
The ADAS1000/ADAS1000-1/ADAS1000-2 do not include
defibrillation protection on chip. Any defibrillation protection
required by the application requires external components.
Figure 61 and Figure 62 show examples of external defibrillator
protection, which is required on each ECG channel, in
the RLD path and in the CM_IN path if using the CE input
mode. Note that, in both cases, the total ECG path resistance is
assumed to be 5 kΩ. The 22 MΩ resistors shown connected to
RLD are optional and used to provide a safe termination voltage
for an open ECG electrode; they may be larger in value. Note
that, if using these resistors, the dc lead-off feature works best
with the highest current setting.
ESIS FILTERING
The ADAS1000/ADAS1000-1/ADAS1000-2 do not include
electrosurgical interference suppression (ESIS) protection on
chip. Any ESIS protection required by the application requires
external components.
ECG PATH INPUT MULTIPLEXING
As shown in Figure 63, signal paths for numerous functions are
provided on each ECG channel (except respiration, which only
connect to the ECG1_LA, ECG2_LL, and ECG3_RA pins).
Note that the channel enable switch occurs after the RLD
amplifier connection, thus allowing the RLD to be connected
(re-directed into any one of the ECG paths). The CM_IN path
is treated the same as the ECG signals.
Figure 61. Possible Defibrillation Protection on ECG Paths Using Neon Bulbs
Figure 62. Possible Defibrillation Protection on ECG Paths Using Diode Protection
Figure 63. Typical ECG Channel Input Multiplexing
09660-018
ELECTRODE
PATIENT
CABLE
4kΩ
ECG1
500Ω 500Ω
ELECTRODE
PATIENT
CABLE
4kΩ
ECG2
RLD
22MΩ
1
22MΩ
1
ARGON/NEON
BULB
ARGON/NEON
BULB
1
OPTIONAL.
SP724
AVDD
SP724
AVDD
500Ω 500Ω
ADAS1000/
ADAS1000-1/
ADAS1000-2
ELECTRODE
PATIENT
CABLE
4.5kΩ
ADAS1000/
ADAS1000-1/
ADAS1000-2
500Ω
ELECTRODE
PATIENT
CABLE
4.5kΩ
500Ω
RLD
22MΩ
1
22MΩ
1
AVDD
AVDD
1
OPTIONAL.
2
TWO SP724 CHANNELS PER ELECTRODE MAY PROVIDE BEST PROTECTION.
SP724
2
SP724
2
ECG1
ECG2
09660-019
INPUT AMPLIFIER
RLD AMP
DCLO
CURRENT
ACLO
CURRENT
RESPIRATION
INPUT CALDAC
CHANNEL
ENABLE
ECG PIN
1.3V VCM_REF
+
–
TO CM
AVERAGING
FROM CM
AVERAGING
TO
FILTERING
ADAS1000
VCM
MUX FOR LEAD CONFIG,
COMMON ELECTRODE
+
–
09660-020