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0
100
200
300
400
500
600
700
800
0 10 20 30 40 50
Input Referred Noise Current,
pA rms in 20Hz Bandwidth
Pleth Current (A)
Duty Cycle 1%
Duty Cycle 5%
Duty Cycle 10%
Duty Cycle 15%
Duty Cycle 20%
Duty Cycle 25%
For each setting RF adjusted for Full-Scale Output.
Amb Cancellation & stage 2 Gain = 4 used for Low
Pleth currents (0.125uA, 0.25uA & 0.5uA).
Noise is calculated in 20Hz B/W.
0
100
200
300
400
500
600
700
800
0 10 20 30 40 50
Input Referred Noise Current,
pA rms in 20Hz Bandwidth
Pleth Current (A)
Duty Cycle 1%
Duty Cycle 5%
Duty Cycle 10%
Duty Cycle 15%
Duty Cycle 20%
Duty Cycle 25%
For each setting RF adjusted for Full-Scale Output.
Amb Cancellation & stage 2 Gain = 4 used for Low
Pleth currents (0.125uA, 0.25uA & 0.5uA).
Noise is calculated in 20Hz B/W.
0
200
400
600
800
1000
1200
1400
0 10 20 30 40 50
Input Referred Noise Current,
pA rms in 5Hz Bandwidth
Pleth Current ( A)
Duty Cycle = 1%
Duty Cycle = 5%
Duty Cycle = 10%
Duty Cycle = 15%
Duty Cycle = 20%
Duty Cycle = 25%
For each setting RF adjusted for Full-Scale Output.
Amb Cancellation & stage 2 Gain = 4 used for
Low Pleth currents (0.125uA, 0.25uA & 0.5uA).
Noise is calculated in 5Hz band.
0
200
400
600
800
1000
1200
1400
0 10 20 30 40 50
Input Referred Noise Current,
pA rms in 5Hz Bandwidth
Pleth Current ( A)
Duty cycle 1%
Duty cycle 5%
Duty cycle 10%
Duty cycle 15%
Duty cycle 20%
Duty cycle 25%
For each setting RF adjusted for Full-Scale Output.
Amb Cancellation & stage 2 Gain = 4 used for
Low Pleth currents (0.125uA, 0.25uA & 0.5uA).
Noise is calculated in 5Hz band.
0
100
200
300
400
500
600
700
0 10 20 30 40 50
Input Referred Noise Current,
pA rms in 5Hz Bandwidth
Pleth Current (A)
Duty Cycle = 1%
Duty Cycle = 5%
Duty Cycle = 10%
Duty Cycle = 15%
Duty Cycle = 20%
Duty Cycle = 25%
For each setting RF adjusted for Full-Scale Output.
Amb Cancellation & stage 2 Gain = 4 used for Low
Pleth currents (0.125uA, 0.25uA & 0.5uA.)
Noise is calculated in 5Hz band.
0
100
200
300
400
500
600
700
800
0 10 20 30 40 50
Input Referred Noise Current,
pA rms in 5Hz Bandwidth
Pleth Current ( A)
Duty Cycle = 1%
Duty Cycle = 5%
Duty Cycle = 10%
Duty Cycle = 15%
Duty Cycle = 20%
Duty Cycle = 25%
For each RF adjusted for Full-Scale Output.
Amb Cancellation & stage 2 Gain = 4 used for Low
Pleth currents (0.125uA, 0.25uA & 0.5uA).
Noise is calculated in 5Hz band.
AFE4490
www.ti.com.cn
ZHCSAT7H –DECEMBER 2012 –REVISED OCTOBER 2014
Typical Characteristics (continued)
At T
A
= 25°C, RX_ANA_SUP = RX_DIG_SUP = 3.0 V, TX_CTRL_SUP = LED_DRV_SUP = 5 V, and f
CLK
= 8 MHz, unless
otherwise noted.
Figure 11. Input-Referred Noise Current vs Figure 12. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 600 Hz) PLETH Current (BW = 5 Hz, PRF = 1200 Hz)
Figure 13. Input-Referred Noise Current vs Figure 14. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 2500 Hz) PLETH Current (BW = 5 Hz, PRF = 5000 Hz)
Figure 15. Input-Referred Noise Current vs Figure 16. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 100 Hz) PLETH Current (BW = 20 Hz, PRF = 300 Hz)
Copyright © 2012–2014, Texas Instruments Incorporated 19