Datasheet

GPIO4
GPIO2
t
BLKDLY
(Blocki gn Si n l)g a
t
PHASE
(ModulationCl ck)o
R
10MW
6
R
10MW
5
C
2.2nF
1
R
40.2kW
2
C
0.1 Fm
2
C
2.2nF
3
AVDD
AVSS
LeftArmLead
RESP_MODP
IN1P
IN2P
RightArmLead
RESP_MODN
IN2N
R
40.2kW
1
C
0.1 Fm
6
C
2.2nF
4
C
2.2nF
5
R
10MW
4
R
10MW
3
AVDD
AVSS
IN1N
ADS1294R/6R/8R
ADS1294, ADS1294R
ADS1296, ADS1296R
ADS1298, ADS1298R
www.ti.com SBAS459I –JANUARY 2010–REVISED JANUARY 2012
Internal Respiration Circuitry with User-Generated Signals (RESP_CTRL = 11b, ADS1294R/6R/8R Only)
In this mode GPIO2, GPIO3, and GPIO4 are automatically configured as inputs. GPIO2, GPIO3, and GPIO4
cannot be used for other purposes. The signals must be provided as described in Figure 68. The internal master
clock is not recommended in this mode.
Figure 68. Internal Respiration (RESP_CTRL = 11b) Timing Diagram
Table 16. Timing Characteristics for Figure 68
(1)
1.65V ≤ DVDD ≤ 3.6V
PARAMETER DESCRIPTION MIN TYP MAX UNIT
t
PHASE
Respiration phase delay 0 157.5 Degrees
t
BLKDLY
Modulation clock rising edge to XOR signal 0 5 ns
(1) Specifications apply from –40°C to +85°C.
ADS129xR Application
The ADS1294R, ADS1296R, and ADS1298R channel 1 with respiration enabled mode cannot be used to
acquire ECG signals. If the RA and LA leads are intended to measure respiration and ECG signals, the two leads
can be wired into channel 1 for respiration and channel 2 for ECG signals, as shown in Figure 69.
NOTE: Patient and input protection circuitry not shown.
Figure 69. Typical Respiration Circuitry
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Product Folder Link(s): ADS1294 ADS1294R ADS1296 ADS1296R ADS1298 ADS1298R