Datasheet

10
11
12
13
14
15
16
0 10 20 30 40 50
Noise-Free Bits in 5Hz Bandwidth
Pleth Current (A)
Duty Cycle 1%
Duty Cycle 5%
Duty Cycle 10%
Duty Cycle 15%
Duty Cycle 20%
Duty Cycle 25%
C017
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).
RMS noise is calculated in 5Hz B/W & NFB is calculated using 6.6 u RMS noise.
10
11
12
13
14
15
16
0 10 20 30 40 50
Noise-Free Bits in 5Hz Bandwidth
Pleth Current (A)
Duty Cycle 1%
Duty Cycle 5%
Duty Cycle 10%
Duty Cycle 15%
Duty Cycle 20%
Duty Cycle 25%
C018
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.)
RMS noise is calculated in 5Hz B/W & NFB is calculated using 6.6 u RMS noise.
0
200
400
600
800
1000
1200
1400
1600
1800
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%
C015
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 band.
0
200
400
600
800
1000
1200
1400
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 band.
C016
0
100
200
300
400
500
600
700
800
900
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%
C013
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 band.
0
200
400
600
800
1000
1200
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%
C014
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 20Hz band.
AFE4490
www.ti.com SBAS602F –DECEMBER 2012–REVISED OCTOBER 2013
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 15. INPUT-REFERRED NOISE CURRENT vs Figure 16. INPUT-REFERRED NOISE CURRENT vs
PLETH CURRENT (BW = 20 Hz, PRF = 600 Hz) PLETH CURRENT (BW = 20 Hz, PRF = 1200 Hz)
Figure 17. INPUT-REFERRED NOISE CURRENT vs Figure 18. INPUT-REFERRED NOISE CURRENT vs
PLETH CURRENT (BW = 20 Hz, PRF = 2500 Hz) PLETH CURRENT (BW = 20 Hz, PRF = 5000 Hz)
Figure 19. NOISE-FREE BITS vs Figure 20. NOISE-FREE BITS vs
PLETH CURRENT (BW = 5 Hz, PRF = 100 Hz) PLETH CURRENT (BW = 5 Hz, PRF = 300 Hz)
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