Preliminary footprints

bmi-8ch-cache.lib

@@ -110,30 +110,6 @@ X P2 2 -200 -50 150 R 50 50 1 1 P
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channel2.sch

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+F 3 "" H 6600 1150 50  0001 C CNN
+	1    6600 1150
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+F 2 "" V 5930 1600 50  0001 C CNN
+F 3 "" H 6000 1600 50  0001 C CNN
+	1    6000 1600
+	0    1    1    0   
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+$Comp
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+P 5600 1600
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+F 1 "86.6k" V 5600 1600 50  0000 C CNN
+F 2 "" V 5530 1600 50  0001 C CNN
+F 3 "" H 5600 1600 50  0001 C CNN
+	1    5600 1600
+	0    1    1    0   
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+$Comp
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+P 6250 1900
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+F 1 "GNDA" H 6250 1750 50  0000 C CNN
+F 2 "" H 6250 1900 50  0001 C CNN
+F 3 "" H 6250 1900 50  0001 C CNN
+	1    6250 1900
+	1    0    0    -1  
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+Text Notes 750  5450 0    87   ~ 0
+Notes:\nDesigned for 0-5V Output\nOutput can swing from AGND to VBATT (5.125-12V) in some failure modes.\nMay damage ADC if input range is <= VBATT\n\nR204, R213: 0.1%\nR208, R209: 1%\nR202, R205, R206 & R203, R207: Metal Foil / Thin Film (Resistor packs preferred)\nALL C: 5%, 16V
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+U 1 1 58D6CE1A
+P 2500 1800
+F 0 "R309" V 2580 1800 50  0000 C CNN
+F 1 "390k" V 2500 1800 50  0000 C CNN
+F 2 "" V 2430 1800 50  0001 C CNN
+F 3 "" H 2500 1800 50  0001 C CNN
+	1    2500 1800
+	1    0    0    -1  
+$EndComp
+$Comp
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+U 1 1 58D6CE1B
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+F 1 "390k" V 2500 1400 50  0000 C CNN
+F 2 "" V 2430 1400 50  0001 C CNN
+F 3 "" H 2500 1400 50  0001 C CNN
+	1    2500 1400
+	1    0    0    -1  
+$EndComp
+Text GLabel 2400 1600 0    60   Input ~ 0
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+F 1 "GNDA" H 9900 1000 50  0000 C CNN
+F 2 "" H 9900 1150 50  0001 C CNN
+F 3 "" H 9900 1150 50  0001 C CNN
+	1    9900 1150
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+F 1 "0.1μF" H 9925 900 50  0000 L CNN
+F 2 "" H 9938 850 50  0001 C CNN
+F 3 "" H 9900 1000 50  0001 C CNN
+	1    9900 1000
+	1    0    0    -1  
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+Text Notes 5300 2450 0    60   ~ 0
+Chebyshev (0.23dB)\n-3dB @ 195Hz\n-50dB @ 3.1kHz
+$Comp
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+F 1 "VBATT" H 6900 1600 50  0000 C CNN
+F 2 "" H 6900 1450 50  0000 C CNN
+F 3 "" H 6900 1450 50  0000 C CNN
+	1    6900 1450
+	1    0    0    -1  
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+F 2 "" H 6900 1950 50  0001 C CNN
+F 3 "" H 6900 1950 50  0001 C CNN
+	1    6900 1950
+	1    0    0    -1  
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+F 0 "U301" H 3400 1725 50  0000 L CNN
+F 1 "AD8227" H 3400 1475 50  0000 L CNN
+F 2 "" H 3350 1600 50  0001 C CNN
+F 3 "" H 3350 1600 50  0001 C CNN
+	1    3250 1600
+	1    0    0    -1  
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+F 3 "" H 2850 1600 50  0001 C CNN
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+F 2 "" H 3250 1300 50  0000 C CNN
+F 3 "" H 3250 1300 50  0000 C CNN
+	1    3250 1300
+	1    0    0    -1  
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Connection ~ 1400 1050
+Wire Wire Line
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+Connection ~ 1600 1050
+Wire Wire Line
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+Wire Wire Line
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+Connection ~ 1600 1950
+Connection ~ 1200 1500
+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
+	1750 1350 1750 1650
+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Connection ~ 5800 1600
+Wire Wire Line
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+Wire Notes Line
+	8350 1000 8350 2450
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Connection ~ 2500 1600
+Wire Wire Line
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+Wire Wire Line
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+Wire Notes Line
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+Connection ~ 9900 850 
+Wire Notes Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
+	3650 1600 5450 1600
+Wire Wire Line
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+Connection ~ 1750 1500
+Wire Wire Line
+	1750 1500 1900 1500
+Text Notes 1950 1050 0    39   ~ 0
+When DC coupled, sensor failure grounds output.
+Text Notes 2750 2350 0    39   ~ 0
+CMRR: >95dB\nInput Voltage Noise Density: <28nV/√Hz\nOutput Voltage Noise Density: <330nV/√Hz\nVoltage Noise (0.1-10Hz): < 0.8μV p-p\n
+Text Notes 7150 2400 0    39   ~ 0
+Offset: <125uV\nOffset Drift: <1.3uv/°C\nVoltage Noise Density: 12nV/√Hz\nVoltage Noise (0.1-10Hz): 0.2μV p-p
+Text Notes 7650 1100 0    60   ~ 0
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+F 1 "10μF" H 10175 900 50  0000 L CNN
+F 2 "" H 10188 850 50  0001 C CNN
+F 3 "" H 10150 1000 50  0001 C CNN
+	1    10150 1000
+	1    0    0    -1  
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+Wire Wire Line
+	9650 850  10150 850 
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+U 1 1 58D6CE24
+P 9900 850
+F 0 "#PWR036" H 9900 700 50  0001 C CNN
+F 1 "VBATT" H 9900 1000 50  0000 C CNN
+F 2 "" H 9900 850 50  0000 C CNN
+F 3 "" H 9900 850 50  0000 C CNN
+	1    9900 850 
+	1    0    0    -1  
+$EndComp
+Text Notes 6950 5250 0    60   ~ 0
+Assumptions:\n - (Initial) DAQ is MCC USB-1208FS (available at BMI)\n     11-bit, max 6250 S/sec for each channel; sequential\n - Target Bandwidth: 195Hz\n - Sampling Rate 6240 S/s\n - Sensor resistance ~2MΩ\n - Respiration motion changes sensor resistance by < -+10%
+Text Notes 7000 6400 0    60   ~ 0
+Analysis Notes:\n\n  1. Steep digital filter 0.4-175Hz\n    - Respiration typically 0.25-0.33Hz\n    - Narrower useful bandwidth likely, modeling needed.\n\n  2. Correct for temporal offset of sample due to sequential sampling.\n\n  3. 2x decimation for 13-bit (ENOB) and noise reduction
+Text Notes 750  7750 0    60   ~ 0
+Open Questions:\n\n1. Trimming the bridge.\n  - Only makes sense w/ DC coupling\n  - Bad tempco\n  - Bad UX\n  - Needed for significant gain\n\n2. AC vs DC Coupling; both have advantages: AC is easier\n\n3. Reducing R202,R203,R206,R207 to decrease Johnson noise: Probably useless.\n  - Changing R202,R206 may break INAMP CMRR\n\n4. Use chopper amps in signal path: Probably bad\n  - Lower total noise for *extremely* small bandwidths (<5Hz?)\n  - Lower offset (if DC coupled)\n\n5. Driven shields for output: Probably useless\n  - Reduce error due to leakage current\n  - No analysis done to determine if this is significant\n  - Current DAQ isn't likely to benefit
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+F 0 "J302" H 9200 1900 50  0000 C CNN
+F 1 "Channel 0" V 9300 1750 50  0000 C CNN
+F 2 "" H 9200 1750 50  0001 C CNN
+F 3 "" H 9200 1750 50  0001 C CNN
+	1    9200 1750
+	1    0    0    1   
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+F 2 "" H 9000 1800 50  0001 C CNN
+F 3 "" H 9000 1800 50  0001 C CNN
+	1    9000 1800
+	1    0    0    -1  
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+F 2 "" H 9688 850 50  0001 C CNN
+F 3 "" H 9650 1000 50  0001 C CNN
+	1    9650 1000
+	1    0    0    -1  
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+F 3 "" H 1400 3050 50  0001 C CNN
+	1    1400 3050
+	1    0    0    -1  
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+F 2 "" V 1330 3650 50  0001 C CNN
+F 3 "" H 1400 3650 50  0001 C CNN
+	1    1400 3650
+	1    0    0    -1  
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+F 2 "" V 1680 3650 50  0001 C CNN
+F 3 "" H 1750 3650 50  0001 C CNN
+	1    1750 3650
+	1    0    0    -1  
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+F 2 "" V 1680 3050 50  0001 C CNN
+F 3 "" H 1750 3050 50  0001 C CNN
+	1    1750 3050
+	1    0    0    -1  
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+F 2 "" H 900 3050 50  0001 C CNN
+F 3 "" H 900 3050 50  0001 C CNN
+	1    900  3050
+	-1   0    0    -1  
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+F 0 "#PWR038" H 1600 3650 50  0001 C CNN
+F 1 "GNDA" H 1600 3750 50  0000 C CNN
+F 2 "" H 1600 3900 50  0001 C CNN
+F 3 "" H 1600 3900 50  0001 C CNN
+	1    1600 3900
+	1    0    0    -1  
+$EndComp
+Text GLabel 1600 2750 1    60   Input ~ 0
+Vref
+Text Label 1050 3350 0    60   ~ 0
+A
+Text Label 1900 3350 2    60   ~ 0
+B
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+A
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+U 1 1 58D6CE2E
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+F 0 "#PWR039" H 3250 3500 50  0001 C CNN
+F 1 "GNDA" H 3250 3600 50  0000 C CNN
+F 2 "" H 3250 3750 50  0001 C CNN
+F 3 "" H 3250 3750 50  0001 C CNN
+	1    3250 3750
+	1    0    0    -1  
+$EndComp
+Text GLabel 3600 3750 2    60   Input ~ 0
+Vref/2
+$Comp
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+U 1 1 58D6CE2F
+P 2200 3250
+F 0 "C309" V 2250 3300 50  0000 L CNN
+F 1 "1µF" V 2050 3150 50  0000 L CNN
+F 2 "" H 2238 3100 50  0001 C CNN
+F 3 "" H 2200 3250 50  0001 C CNN
+	1    2200 3250
+	0    1    1    0   
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+$Comp
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+U 1 1 58D6CE30
+P 2200 3650
+F 0 "C311" V 2150 3700 50  0000 L CNN
+F 1 "1µF" V 2350 3550 50  0000 L CNN
+F 2 "" H 2238 3500 50  0001 C CNN
+F 3 "" H 2200 3650 50  0001 C CNN
+	1    2200 3650
+	0    1    1    0   
+$EndComp
+Text Notes 1950 2850 0    60   ~ 0
+Optional AC Coupling\n3dB down @ 0.4Hz
+$Comp
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+U 2 1 58D6CE31
+P 6950 3550
+F 0 "U302" H 7150 3700 50  0000 L CNN
+F 1 "AD8622" H 7150 3400 50  0000 L CNN
+F 2 "" H 6950 3550 50  0001 C CNN
+F 3 "" H 6950 3550 50  0001 C CNN
+	2    6950 3550
+	1    0    0    -1  
+$EndComp
+$Comp
+L C C310
+U 1 1 58D6CE32
+P 6250 3600
+F 0 "C310" H 6275 3700 50  0000 L CNN
+F 1 "910pF" H 6150 3500 50  0000 L CNN
+F 2 "" H 6288 3450 50  0001 C CNN
+F 3 "" H 6250 3600 50  0001 C CNN
+	1    6250 3600
+	1    0    0    -1  
+$EndComp
+$Comp
+L C C308
+U 1 1 58D6CE33
+P 6600 3000
+F 0 "C308" V 6550 3050 50  0000 L CNN
+F 1 "9.1nF" V 6650 3050 50  0000 L CNN
+F 2 "" H 6638 2850 50  0001 C CNN
+F 3 "" H 6600 3000 50  0001 C CNN
+	1    6600 3000
+	0    1    1    0   
+$EndComp
+$Comp
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+U 1 1 58D6CE34
+P 6000 3450
+F 0 "R315" V 6080 3450 50  0000 C CNN
+F 1 "1.15M" V 6000 3450 39  0000 C CNN
+F 2 "" V 5930 3450 50  0001 C CNN
+F 3 "" H 6000 3450 50  0001 C CNN
+	1    6000 3450
+	0    1    1    0   
+$EndComp
+$Comp
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+U 1 1 58D6CE35
+P 5600 3450
+F 0 "R314" V 5680 3450 50  0000 C CNN
+F 1 "86.6k" V 5600 3450 50  0000 C CNN
+F 2 "" V 5530 3450 50  0001 C CNN
+F 3 "" H 5600 3450 50  0001 C CNN
+	1    5600 3450
+	0    1    1    0   
+$EndComp
+$Comp
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+U 1 1 58D6CE36
+P 6250 3750
+F 0 "#PWR040" H 6250 3500 50  0001 C CNN
+F 1 "GNDA" H 6250 3600 50  0000 C CNN
+F 2 "" H 6250 3750 50  0001 C CNN
+F 3 "" H 6250 3750 50  0001 C CNN
+	1    6250 3750
+	1    0    0    -1  
+$EndComp
+$Comp
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+U 1 1 58D6CE37
+P 2500 3650
+F 0 "R318" V 2580 3650 50  0000 C CNN
+F 1 "390k" V 2500 3650 50  0000 C CNN
+F 2 "" V 2430 3650 50  0001 C CNN
+F 3 "" H 2500 3650 50  0001 C CNN
+	1    2500 3650
+	1    0    0    -1  
+$EndComp
+$Comp
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+U 1 1 58D6CE38
+P 2500 3250
+F 0 "R312" V 2580 3250 50  0000 C CNN
+F 1 "390k" V 2500 3250 50  0000 C CNN
+F 2 "" V 2430 3250 50  0001 C CNN
+F 3 "" H 2500 3250 50  0001 C CNN
+	1    2500 3250
+	1    0    0    -1  
+$EndComp
+Text GLabel 2400 3450 0    60   Input ~ 0
+Vref/2
+Text Notes 5300 4300 0    60   ~ 0
+Chebyshev (0.23dB)\n-3dB @ 195Hz\n-50dB @ 3.1kHz
+$Comp
+L VBATT #PWR041
+U 1 1 58D6CE39
+P 6900 3300
+F 0 "#PWR041" H 6900 3150 50  0001 C CNN
+F 1 "VBATT" H 6900 3450 50  0000 C CNN
+F 2 "" H 6900 3300 50  0000 C CNN
+F 3 "" H 6900 3300 50  0000 C CNN
+	1    6900 3300
+	1    0    0    -1  
+$EndComp
+$Comp
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+U 1 1 58D6CE3A
+P 6900 3800
+F 0 "#PWR042" H 6900 3550 50  0001 C CNN
+F 1 "GNDA" H 6900 3650 50  0000 C CNN
+F 2 "" H 6900 3800 50  0001 C CNN
+F 3 "" H 6900 3800 50  0001 C CNN
+	1    6900 3800
+	1    0    0    -1  
+$EndComp
+$Comp
+L AD8227 U303
+U 1 1 58D6CE3B
+P 3250 3450
+F 0 "U303" H 3400 3575 50  0000 L CNN
+F 1 "AD8227" H 3400 3325 50  0000 L CNN
+F 2 "" H 3350 3450 50  0001 C CNN
+F 3 "" H 3350 3450 50  0001 C CNN
+	1    3250 3450
+	1    0    0    -1  
+$EndComp
+$Comp
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+U 1 1 58D6CE3C
+P 2850 3450
+F 0 "R313" V 2900 3350 50  0000 L CNN
+F 1 "1.78k" V 2845 3385 31  0000 L CNN
+F 2 "" H 2850 3450 50  0001 C CNN
+F 3 "" H 2850 3450 50  0001 C CNN
+	1    2850 3450
+	1    0    0    -1  
+$EndComp
+Text Notes 2750 3300 0    39   ~ 0
+G=50
+$Comp
+L VBATT #PWR043
+U 1 1 58D6CE3D
+P 3250 3150
+F 0 "#PWR043" H 3250 3000 50  0001 C CNN
+F 1 "VBATT" H 3250 3300 50  0000 C CNN
+F 2 "" H 3250 3150 50  0000 C CNN
+F 3 "" H 3250 3150 50  0000 C CNN
+	1    3250 3150
+	1    0    0    -1  
+$EndComp
+Wire Wire Line
+	1200 3100 1200 3350
+Wire Wire Line
+	1200 3100 1100 3100
+Connection ~ 1400 3350
+Wire Wire Line
+	1100 3000 1100 2900
+Wire Wire Line
+	1100 2900 1750 2900
+Connection ~ 1400 2900
+Wire Wire Line
+	1600 2900 1600 2750
+Connection ~ 1600 2900
+Wire Wire Line
+	1400 3800 1750 3800
+Wire Wire Line
+	1600 3800 1600 3900
+Connection ~ 1600 3800
+Connection ~ 1200 3350
+Wire Wire Line
+	1050 3350 1400 3350
+Wire Wire Line
+	1400 3200 1400 3500
+Wire Wire Line
+	1750 3200 1750 3500
+Wire Wire Line
+	1900 3350 1900 3650
+Wire Wire Line
+	1850 3250 2050 3250
+Wire Notes Line
+	2050 2950 2700 2950
+Wire Wire Line
+	6650 3650 6500 3650
+Wire Wire Line
+	6500 3650 6500 4050
+Wire Wire Line
+	7600 3000 7600 4050
+Wire Wire Line
+	7250 3550 9000 3550
+Wire Wire Line
+	5750 3450 5850 3450
+Wire Wire Line
+	6150 3450 6650 3450
+Connection ~ 6250 3450
+Wire Wire Line
+	5800 3450 5800 3000
+Wire Wire Line
+	5800 3000 6450 3000
+Connection ~ 5800 3450
+Wire Wire Line
+	7600 3000 6750 3000
+Connection ~ 7600 3550
+Wire Notes Line
+	5250 2850 8350 2850
+Wire Notes Line
+	8350 2850 8350 4300
+Wire Notes Line
+	5250 4300 5250 2850
+Wire Wire Line
+	7600 4050 6500 4050
+Wire Wire Line
+	2350 3100 2750 3100
+Wire Wire Line
+	2350 3100 2350 3250
+Connection ~ 2500 3100
+Wire Wire Line
+	2350 3650 2350 3800
+Wire Wire Line
+	2500 3400 2500 3500
+Wire Wire Line
+	2400 3450 2500 3450
+Connection ~ 2500 3450
+Wire Wire Line
+	1900 3650 2050 3650
+Wire Wire Line
+	2350 3800 2750 3800
+Connection ~ 2500 3800
+Wire Notes Line
+	2050 3950 2700 3950
+Wire Notes Line
+	2700 3950 2700 2950
+Wire Notes Line
+	2050 2950 2050 3950
+Wire Notes Line
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+Wire Wire Line
+	3600 3750 3350 3750
+Wire Wire Line
+	2750 3100 2950 3250
+Wire Wire Line
+	2750 3800 2950 3650
+Wire Wire Line
+	3650 3450 5450 3450
+Wire Wire Line
+	2950 3350 2850 3350
+Wire Wire Line
+	2950 3550 2850 3550
+Connection ~ 1750 3350
+Wire Wire Line
+	1750 3350 1900 3350
+Text Notes 1950 2900 0    39   ~ 0
+When DC coupled, sensor failure grounds output.
+Text Notes 2750 4200 0    39   ~ 0
+CMRR: >95dB\nInput Voltage Noise Density: <28nV/√Hz\nOutput Voltage Noise Density: <330nV/√Hz\nVoltage Noise (0.1-10Hz): < 0.8μV p-p\n
+Text Notes 7150 4250 0    39   ~ 0
+Offset: <125uV\nOffset Drift: <1.3uv/°C\nVoltage Noise Density: 12nV/√Hz\nVoltage Noise (0.1-10Hz): 0.2μV p-p
+Text Notes 7650 2950 0    60   ~ 0
+Antialias Filter
+$Comp
+L CONN_01X02 J304
+U 1 1 58D6CE3E
+P 9200 3600
+F 0 "J304" H 9200 3750 50  0000 C CNN
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+F 2 "" H 9200 3600 50  0001 C CNN
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+Text Notes 3500 5950 0    60   ~ 0
+Problems:\n\n  - AD8622 isn't RRIO; will saturate at (V+)-1.2V.\n      Near the end of battery life; this could be less that 5V.
+$EndSCHEMATC

channel4.sch

@@ -0,0 +1,898 @@
+EESchema Schematic File Version 2
+LIBS:power
+LIBS:device
+LIBS:transistors
+LIBS:conn
+LIBS:linear
+LIBS:regul
+LIBS:74xx
+LIBS:cmos4000
+LIBS:adc-dac
+LIBS:memory
+LIBS:xilinx
+LIBS:microcontrollers
+LIBS:dsp
+LIBS:microchip
+LIBS:analog_switches
+LIBS:motorola
+LIBS:texas
+LIBS:intel
+LIBS:audio
+LIBS:interface
+LIBS:digital-audio
+LIBS:philips
+LIBS:display
+LIBS:cypress
+LIBS:siliconi
+LIBS:opto
+LIBS:atmel
+LIBS:contrib
+LIBS:valves
+LIBS:nocko
+LIBS:bmi-8ch-cache
+EELAYER 25 0
+EELAYER END
+$Descr USLetter 11000 8500
+encoding utf-8
+Sheet 4 5
+Title "Input Channel 4 & 5"
+Date "2017-03-23"
+Rev "AA"
+Comp "Monadnock Systems"
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+Notes:\nDesigned for 0-5V Output\nOutput can swing from AGND to VBATT (5.125-12V) in some failure modes.\nMay damage ADC if input range is <= VBATT\n\nR204, R213: 0.1%\nR208, R209: 1%\nR202, R205, R206 & R203, R207: Metal Foil / Thin Film (Resistor packs preferred)\nALL C: 5%, 16V
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+Text Notes 5300 2450 0    60   ~ 0
+Chebyshev (0.23dB)\n-3dB @ 195Hz\n-50dB @ 3.1kHz
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+When DC coupled, sensor failure grounds output.
+Text Notes 2750 2350 0    39   ~ 0
+CMRR: >95dB\nInput Voltage Noise Density: <28nV/√Hz\nOutput Voltage Noise Density: <330nV/√Hz\nVoltage Noise (0.1-10Hz): < 0.8μV p-p\n
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+Offset: <125uV\nOffset Drift: <1.3uv/°C\nVoltage Noise Density: 12nV/√Hz\nVoltage Noise (0.1-10Hz): 0.2μV p-p
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+Assumptions:\n - (Initial) DAQ is MCC USB-1208FS (available at BMI)\n     11-bit, max 6250 S/sec for each channel; sequential\n - Target Bandwidth: 195Hz\n - Sampling Rate 6240 S/s\n - Sensor resistance ~2MΩ\n - Respiration motion changes sensor resistance by < -+10%
+Text Notes 7000 6400 0    60   ~ 0
+Analysis Notes:\n\n  1. Steep digital filter 0.4-175Hz\n    - Respiration typically 0.25-0.33Hz\n    - Narrower useful bandwidth likely, modeling needed.\n\n  2. Correct for temporal offset of sample due to sequential sampling.\n\n  3. 2x decimation for 13-bit (ENOB) and noise reduction
+Text Notes 750  7750 0    60   ~ 0
+Open Questions:\n\n1. Trimming the bridge.\n  - Only makes sense w/ DC coupling\n  - Bad tempco\n  - Bad UX\n  - Needed for significant gain\n\n2. AC vs DC Coupling; both have advantages: AC is easier\n\n3. Reducing R202,R203,R206,R207 to decrease Johnson noise: Probably useless.\n  - Changing R202,R206 may break INAMP CMRR\n\n4. Use chopper amps in signal path: Probably bad\n  - Lower total noise for *extremely* small bandwidths (<5Hz?)\n  - Lower offset (if DC coupled)\n\n5. Driven shields for output: Probably useless\n  - Reduce error due to leakage current\n  - No analysis done to determine if this is significant\n  - Current DAQ isn't likely to benefit
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+F 3 "" H 6250 3750 50  0001 C CNN
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+F 3 "" H 2500 3650 50  0001 C CNN
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+F 3 "" H 2500 3250 50  0001 C CNN
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+$EndComp
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+Text Notes 5300 4300 0    60   ~ 0
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+F 2 "" H 6900 3300 50  0000 C CNN
+F 3 "" H 6900 3300 50  0000 C CNN
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+F 3 "" H 6900 3800 50  0001 C CNN
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+F 3 "" H 3350 3450 50  0001 C CNN
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+When DC coupled, sensor failure grounds output.
+Text Notes 2750 4200 0    39   ~ 0
+CMRR: >95dB\nInput Voltage Noise Density: <28nV/√Hz\nOutput Voltage Noise Density: <330nV/√Hz\nVoltage Noise (0.1-10Hz): < 0.8μV p-p\n
+Text Notes 7150 4250 0    39   ~ 0
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+F 2 "" H 9200 3600 50  0001 C CNN
+F 3 "" H 9200 3600 50  0001 C CNN
+	1    9200 3600
+	1    0    0    1   
+$EndComp
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+F 2 "" H 9000 3650 50  0001 C CNN
+F 3 "" H 9000 3650 50  0001 C CNN
+	1    9000 3650
+	1    0    0    -1  
+$EndComp
+Text Notes 3500 5950 0    60   ~ 0
+Problems:\n\n  - AD8622 isn't RRIO; will saturate at (V+)-1.2V.\n      Near the end of battery life; this could be less that 5V.
+$EndSCHEMATC

channel6.sch

@@ -0,0 +1,898 @@
+EESchema Schematic File Version 2
+LIBS:power
+LIBS:device
+LIBS:transistors
+LIBS:conn
+LIBS:linear
+LIBS:regul
+LIBS:74xx
+LIBS:cmos4000
+LIBS:adc-dac
+LIBS:memory
+LIBS:xilinx
+LIBS:microcontrollers
+LIBS:dsp
+LIBS:microchip
+LIBS:analog_switches
+LIBS:motorola
+LIBS:texas
+LIBS:intel
+LIBS:audio
+LIBS:interface
+LIBS:digital-audio
+LIBS:philips
+LIBS:display
+LIBS:cypress
+LIBS:siliconi
+LIBS:opto
+LIBS:atmel
+LIBS:contrib
+LIBS:valves
+LIBS:nocko
+LIBS:bmi-8ch-cache
+EELAYER 25 0
+EELAYER END
+$Descr USLetter 11000 8500
+encoding utf-8
+Sheet 5 5
+Title "Input Channel 6 & 7"
+Date "2017-03-23"
+Rev "AA"
+Comp "Monadnock Systems"
+Comment1 ""
+Comment2 ""
+Comment3 ""
+Comment4 ""
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+F 2 "" V 1330 1200 50  0001 C CNN
+F 3 "" H 1400 1200 50  0001 C CNN
+	1    1400 1200
+	1    0    0    -1  
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+F 2 "" V 1330 1800 50  0001 C CNN
+F 3 "" H 1400 1800 50  0001 C CNN
+	1    1400 1800
+	1    0    0    -1  
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+F 2 "" H 900 1200 50  0001 C CNN
+F 3 "" H 900 1200 50  0001 C CNN
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+F 2 "" H 1600 2050 50  0001 C CNN
+F 3 "" H 1600 2050 50  0001 C CNN
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+F 3 "" H 3250 1900 50  0001 C CNN
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+F 3 "" H 2200 1800 50  0001 C CNN
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+Text Notes 1950 1000 0    60   ~ 0
+Optional AC Coupling\n3dB down @ 0.4Hz
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+F 3 "" H 6950 1700 50  0001 C CNN
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+F 3 "" H 6250 1750 50  0001 C CNN
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+F 3 "" H 5600 1600 50  0001 C CNN
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+F 2 "" H 6250 1900 50  0001 C CNN
+F 3 "" H 6250 1900 50  0001 C CNN
+	1    6250 1900
+	1    0    0    -1  
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+Text Notes 750  5450 0    87   ~ 0
+Notes:\nDesigned for 0-5V Output\nOutput can swing from AGND to VBATT (5.125-12V) in some failure modes.\nMay damage ADC if input range is <= VBATT\n\nR204, R213: 0.1%\nR208, R209: 1%\nR202, R205, R206 & R203, R207: Metal Foil / Thin Film (Resistor packs preferred)\nALL C: 5%, 16V
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+F 1 "390k" V 2500 1800 50  0000 C CNN
+F 2 "" V 2430 1800 50  0001 C CNN
+F 3 "" H 2500 1800 50  0001 C CNN
+	1    2500 1800
+	1    0    0    -1  
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+F 1 "390k" V 2500 1400 50  0000 C CNN
+F 2 "" V 2430 1400 50  0001 C CNN
+F 3 "" H 2500 1400 50  0001 C CNN
+	1    2500 1400
+	1    0    0    -1  
+$EndComp
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+$Comp
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+P 9900 1150
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+F 1 "GNDA" H 9900 1000 50  0000 C CNN
+F 2 "" H 9900 1150 50  0001 C CNN
+F 3 "" H 9900 1150 50  0001 C CNN
+	1    9900 1150
+	1    0    0    -1  
+$EndComp
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+F 1 "0.1μF" H 9925 900 50  0000 L CNN
+F 2 "" H 9938 850 50  0001 C CNN
+F 3 "" H 9900 1000 50  0001 C CNN
+	1    9900 1000
+	1    0    0    -1  
+$EndComp
+Text Notes 5300 2450 0    60   ~ 0
+Chebyshev (0.23dB)\n-3dB @ 195Hz\n-50dB @ 3.1kHz
+$Comp
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+U 1 1 58D6DA25
+P 6900 1450
+F 0 "#PWR065" H 6900 1300 50  0001 C CNN
+F 1 "VBATT" H 6900 1600 50  0000 C CNN
+F 2 "" H 6900 1450 50  0000 C CNN
+F 3 "" H 6900 1450 50  0000 C CNN
+	1    6900 1450
+	1    0    0    -1  
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+U 1 1 58D6DA26
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+F 0 "#PWR066" H 6900 1700 50  0001 C CNN
+F 1 "GNDA" H 6900 1800 50  0000 C CNN
+F 2 "" H 6900 1950 50  0001 C CNN
+F 3 "" H 6900 1950 50  0001 C CNN
+	1    6900 1950
+	1    0    0    -1  
+$EndComp
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+U 1 1 58D6DA27
+P 3250 1600
+F 0 "U501" H 3400 1725 50  0000 L CNN
+F 1 "AD8227" H 3400 1475 50  0000 L CNN
+F 2 "" H 3350 1600 50  0001 C CNN
+F 3 "" H 3350 1600 50  0001 C CNN
+	1    3250 1600
+	1    0    0    -1  
+$EndComp
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+U 1 1 58D6DA28
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+F 0 "R504" V 2900 1500 50  0000 L CNN
+F 1 "1.78k" V 2845 1535 31  0000 L CNN
+F 2 "" H 2850 1600 50  0001 C CNN
+F 3 "" H 2850 1600 50  0001 C CNN
+	1    2850 1600
+	1    0    0    -1  
+$EndComp
+Text Notes 2750 1450 0    39   ~ 0
+G=50
+$Comp
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+U 1 1 58D6DA29
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+F 0 "#PWR067" H 3250 1150 50  0001 C CNN
+F 1 "VBATT" H 3250 1450 50  0000 C CNN
+F 2 "" H 3250 1300 50  0000 C CNN
+F 3 "" H 3250 1300 50  0000 C CNN
+	1    3250 1300
+	1    0    0    -1  
+$EndComp
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+Wire Wire Line
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+Wire Wire Line
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+Connection ~ 1400 1050
+Wire Wire Line
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+Connection ~ 1600 1050
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Connection ~ 2500 1950
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+Wire Notes Line
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+Wire Notes Line
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+Connection ~ 9900 1150
+Connection ~ 9900 850 
+Wire Notes Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
+	2950 1700 2850 1700
+Connection ~ 1750 1500
+Wire Wire Line
+	1750 1500 1900 1500
+Text Notes 1950 1050 0    39   ~ 0
+When DC coupled, sensor failure grounds output.
+Text Notes 2750 2350 0    39   ~ 0
+CMRR: >95dB\nInput Voltage Noise Density: <28nV/√Hz\nOutput Voltage Noise Density: <330nV/√Hz\nVoltage Noise (0.1-10Hz): < 0.8μV p-p\n
+Text Notes 7150 2400 0    39   ~ 0
+Offset: <125uV\nOffset Drift: <1.3uv/°C\nVoltage Noise Density: 12nV/√Hz\nVoltage Noise (0.1-10Hz): 0.2μV p-p
+Text Notes 7650 1100 0    60   ~ 0
+Antialias Filter
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+U 1 1 58D6DA2A
+P 10150 1000
+F 0 "C503" H 10175 1100 50  0000 L CNN
+F 1 "10μF" H 10175 900 50  0000 L CNN
+F 2 "" H 10188 850 50  0001 C CNN
+F 3 "" H 10150 1000 50  0001 C CNN
+	1    10150 1000
+	1    0    0    -1  
+$EndComp
+Wire Wire Line
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+Wire Wire Line
+	9650 850  10150 850 
+$Comp
+L VBATT #PWR068
+U 1 1 58D6DA2B
+P 9900 850
+F 0 "#PWR068" H 9900 700 50  0001 C CNN
+F 1 "VBATT" H 9900 1000 50  0000 C CNN
+F 2 "" H 9900 850 50  0000 C CNN
+F 3 "" H 9900 850 50  0000 C CNN
+	1    9900 850 
+	1    0    0    -1  
+$EndComp
+Text Notes 6950 5250 0    60   ~ 0
+Assumptions:\n - (Initial) DAQ is MCC USB-1208FS (available at BMI)\n     11-bit, max 6250 S/sec for each channel; sequential\n - Target Bandwidth: 195Hz\n - Sampling Rate 6240 S/s\n - Sensor resistance ~2MΩ\n - Respiration motion changes sensor resistance by < -+10%
+Text Notes 7000 6400 0    60   ~ 0
+Analysis Notes:\n\n  1. Steep digital filter 0.4-175Hz\n    - Respiration typically 0.25-0.33Hz\n    - Narrower useful bandwidth likely, modeling needed.\n\n  2. Correct for temporal offset of sample due to sequential sampling.\n\n  3. 2x decimation for 13-bit (ENOB) and noise reduction
+Text Notes 750  7750 0    60   ~ 0
+Open Questions:\n\n1. Trimming the bridge.\n  - Only makes sense w/ DC coupling\n  - Bad tempco\n  - Bad UX\n  - Needed for significant gain\n\n2. AC vs DC Coupling; both have advantages: AC is easier\n\n3. Reducing R202,R203,R206,R207 to decrease Johnson noise: Probably useless.\n  - Changing R202,R206 may break INAMP CMRR\n\n4. Use chopper amps in signal path: Probably bad\n  - Lower total noise for *extremely* small bandwidths (<5Hz?)\n  - Lower offset (if DC coupled)\n\n5. Driven shields for output: Probably useless\n  - Reduce error due to leakage current\n  - No analysis done to determine if this is significant\n  - Current DAQ isn't likely to benefit
+$Comp
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+U 1 1 58D6DA2C
+P 9200 1750
+F 0 "J502" H 9200 1900 50  0000 C CNN
+F 1 "Channel 0" V 9300 1750 50  0000 C CNN
+F 2 "" H 9200 1750 50  0001 C CNN
+F 3 "" H 9200 1750 50  0001 C CNN
+	1    9200 1750
+	1    0    0    1   
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+$Comp
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+F 1 "GNDA" H 9000 1650 50  0000 C CNN
+F 2 "" H 9000 1800 50  0001 C CNN
+F 3 "" H 9000 1800 50  0001 C CNN
+	1    9000 1800
+	1    0    0    -1  
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+F 1 "0.1μF" H 9675 900 50  0000 L CNN
+F 2 "" H 9688 850 50  0001 C CNN
+F 3 "" H 9650 1000 50  0001 C CNN
+	1    9650 1000
+	1    0    0    -1  
+$EndComp
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+F 0 "R510" V 1480 3050 50  0000 C CNN
+F 1 "DNP" V 1400 3050 50  0000 C CNN
+F 2 "" V 1330 3050 50  0001 C CNN
+F 3 "" H 1400 3050 50  0001 C CNN
+	1    1400 3050
+	1    0    0    -1  
+$EndComp
+$Comp
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+F 0 "R516" V 1480 3650 50  0000 C CNN
+F 1 "2M" V 1400 3650 50  0000 C CNN
+F 2 "" V 1330 3650 50  0001 C CNN
+F 3 "" H 1400 3650 50  0001 C CNN
+	1    1400 3650
+	1    0    0    -1  
+$EndComp
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+F 0 "R517" V 1830 3650 50  0000 C CNN
+F 1 "2M" V 1750 3650 50  0000 C CNN
+F 2 "" V 1680 3650 50  0001 C CNN
+F 3 "" H 1750 3650 50  0001 C CNN
+	1    1750 3650
+	1    0    0    -1  
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+F 1 "2M" V 1750 3050 50  0000 C CNN
+F 2 "" V 1680 3050 50  0001 C CNN
+F 3 "" H 1750 3050 50  0001 C CNN
+	1    1750 3050
+	1    0    0    -1  
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+L CONN_01X02 J503
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+F 0 "J503" H 900 3200 50  0000 C CNN
+F 1 "Sensor" V 1000 3050 50  0000 C CNN
+F 2 "" H 900 3050 50  0001 C CNN
+F 3 "" H 900 3050 50  0001 C CNN
+	1    900  3050
+	-1   0    0    -1  
+$EndComp
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+U 1 1 58D6DA34
+P 1600 3900
+F 0 "#PWR070" H 1600 3650 50  0001 C CNN
+F 1 "GNDA" H 1600 3750 50  0000 C CNN
+F 2 "" H 1600 3900 50  0001 C CNN
+F 3 "" H 1600 3900 50  0001 C CNN
+	1    1600 3900
+	1    0    0    -1  
+$EndComp
+Text GLabel 1600 2750 1    60   Input ~ 0
+Vref
+Text Label 1050 3350 0    60   ~ 0
+A
+Text Label 1900 3350 2    60   ~ 0
+B
+Text Label 1850 3250 0    60   ~ 0
+A
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+U 1 1 58D6DA35
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+F 0 "#PWR071" H 3250 3500 50  0001 C CNN
+F 1 "GNDA" H 3250 3600 50  0000 C CNN
+F 2 "" H 3250 3750 50  0001 C CNN
+F 3 "" H 3250 3750 50  0001 C CNN
+	1    3250 3750
+	1    0    0    -1  
+$EndComp
+Text GLabel 3600 3750 2    60   Input ~ 0
+Vref/2
+$Comp
+L C C509
+U 1 1 58D6DA36
+P 2200 3250
+F 0 "C509" V 2250 3300 50  0000 L CNN
+F 1 "1µF" V 2050 3150 50  0000 L CNN
+F 2 "" H 2238 3100 50  0001 C CNN
+F 3 "" H 2200 3250 50  0001 C CNN
+	1    2200 3250
+	0    1    1    0   
+$EndComp
+$Comp
+L C C511
+U 1 1 58D6DA37
+P 2200 3650
+F 0 "C511" V 2150 3700 50  0000 L CNN
+F 1 "1µF" V 2350 3550 50  0000 L CNN
+F 2 "" H 2238 3500 50  0001 C CNN
+F 3 "" H 2200 3650 50  0001 C CNN
+	1    2200 3650
+	0    1    1    0   
+$EndComp
+Text Notes 1950 2850 0    60   ~ 0
+Optional AC Coupling\n3dB down @ 0.4Hz
+$Comp
+L AD8622 U502
+U 2 1 58D6DA38
+P 6950 3550
+F 0 "U502" H 7150 3700 50  0000 L CNN
+F 1 "AD8622" H 7150 3400 50  0000 L CNN
+F 2 "" H 6950 3550 50  0001 C CNN
+F 3 "" H 6950 3550 50  0001 C CNN
+	2    6950 3550
+	1    0    0    -1  
+$EndComp
+$Comp
+L C C510
+U 1 1 58D6DA39
+P 6250 3600
+F 0 "C510" H 6275 3700 50  0000 L CNN
+F 1 "910pF" H 6150 3500 50  0000 L CNN
+F 2 "" H 6288 3450 50  0001 C CNN
+F 3 "" H 6250 3600 50  0001 C CNN
+	1    6250 3600
+	1    0    0    -1  
+$EndComp
+$Comp
+L C C508
+U 1 1 58D6DA3A
+P 6600 3000
+F 0 "C508" V 6550 3050 50  0000 L CNN
+F 1 "9.1nF" V 6650 3050 50  0000 L CNN
+F 2 "" H 6638 2850 50  0001 C CNN
+F 3 "" H 6600 3000 50  0001 C CNN
+	1    6600 3000
+	0    1    1    0   
+$EndComp
+$Comp
+L R R515
+U 1 1 58D6DA3B
+P 6000 3450
+F 0 "R515" V 6080 3450 50  0000 C CNN
+F 1 "1.15M" V 6000 3450 39  0000 C CNN
+F 2 "" V 5930 3450 50  0001 C CNN
+F 3 "" H 6000 3450 50  0001 C CNN
+	1    6000 3450
+	0    1    1    0   
+$EndComp
+$Comp
+L R R514
+U 1 1 58D6DA3C
+P 5600 3450
+F 0 "R514" V 5680 3450 50  0000 C CNN
+F 1 "86.6k" V 5600 3450 50  0000 C CNN
+F 2 "" V 5530 3450 50  0001 C CNN
+F 3 "" H 5600 3450 50  0001 C CNN
+	1    5600 3450
+	0    1    1    0   
+$EndComp
+$Comp
+L GNDA #PWR072
+U 1 1 58D6DA3D
+P 6250 3750
+F 0 "#PWR072" H 6250 3500 50  0001 C CNN
+F 1 "GNDA" H 6250 3600 50  0000 C CNN
+F 2 "" H 6250 3750 50  0001 C CNN
+F 3 "" H 6250 3750 50  0001 C CNN
+	1    6250 3750
+	1    0    0    -1  
+$EndComp
+$Comp
+L R R518
+U 1 1 58D6DA3E
+P 2500 3650
+F 0 "R518" V 2580 3650 50  0000 C CNN
+F 1 "390k" V 2500 3650 50  0000 C CNN
+F 2 "" V 2430 3650 50  0001 C CNN
+F 3 "" H 2500 3650 50  0001 C CNN
+	1    2500 3650
+	1    0    0    -1  
+$EndComp
+$Comp
+L R R512
+U 1 1 58D6DA3F
+P 2500 3250
+F 0 "R512" V 2580 3250 50  0000 C CNN
+F 1 "390k" V 2500 3250 50  0000 C CNN
+F 2 "" V 2430 3250 50  0001 C CNN
+F 3 "" H 2500 3250 50  0001 C CNN
+	1    2500 3250
+	1    0    0    -1  
+$EndComp
+Text GLabel 2400 3450 0    60   Input ~ 0
+Vref/2
+Text Notes 5300 4300 0    60   ~ 0
+Chebyshev (0.23dB)\n-3dB @ 195Hz\n-50dB @ 3.1kHz
+$Comp
+L VBATT #PWR073
+U 1 1 58D6DA40
+P 6900 3300
+F 0 "#PWR073" H 6900 3150 50  0001 C CNN
+F 1 "VBATT" H 6900 3450 50  0000 C CNN
+F 2 "" H 6900 3300 50  0000 C CNN
+F 3 "" H 6900 3300 50  0000 C CNN
+	1    6900 3300
+	1    0    0    -1  
+$EndComp
+$Comp
+L GNDA #PWR074
+U 1 1 58D6DA41
+P 6900 3800
+F 0 "#PWR074" H 6900 3550 50  0001 C CNN
+F 1 "GNDA" H 6900 3650 50  0000 C CNN
+F 2 "" H 6900 3800 50  0001 C CNN
+F 3 "" H 6900 3800 50  0001 C CNN
+	1    6900 3800
+	1    0    0    -1  
+$EndComp
+$Comp
+L AD8227 U503
+U 1 1 58D6DA42
+P 3250 3450
+F 0 "U503" H 3400 3575 50  0000 L CNN
+F 1 "AD8227" H 3400 3325 50  0000 L CNN
+F 2 "" H 3350 3450 50  0001 C CNN
+F 3 "" H 3350 3450 50  0001 C CNN
+	1    3250 3450
+	1    0    0    -1  
+$EndComp
+$Comp
+L R_Small R513
+U 1 1 58D6DA43
+P 2850 3450
+F 0 "R513" V 2900 3350 50  0000 L CNN
+F 1 "1.78k" V 2845 3385 31  0000 L CNN
+F 2 "" H 2850 3450 50  0001 C CNN
+F 3 "" H 2850 3450 50  0001 C CNN
+	1    2850 3450
+	1    0    0    -1  
+$EndComp
+Text Notes 2750 3300 0    39   ~ 0
+G=50
+$Comp
+L VBATT #PWR075
+U 1 1 58D6DA44
+P 3250 3150
+F 0 "#PWR075" H 3250 3000 50  0001 C CNN
+F 1 "VBATT" H 3250 3300 50  0000 C CNN
+F 2 "" H 3250 3150 50  0000 C CNN
+F 3 "" H 3250 3150 50  0000 C CNN
+	1    3250 3150
+	1    0    0    -1  
+$EndComp
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+Wire Wire Line
+	1200 3100 1100 3100
+Connection ~ 1400 3350
+Wire Wire Line
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+Wire Wire Line
+	1100 2900 1750 2900
+Connection ~ 1400 2900
+Wire Wire Line
+	1600 2900 1600 2750
+Connection ~ 1600 2900
+Wire Wire Line
+	1400 3800 1750 3800
+Wire Wire Line
+	1600 3800 1600 3900
+Connection ~ 1600 3800
+Connection ~ 1200 3350
+Wire Wire Line
+	1050 3350 1400 3350
+Wire Wire Line
+	1400 3200 1400 3500
+Wire Wire Line
+	1750 3200 1750 3500
+Wire Wire Line
+	1900 3350 1900 3650
+Wire Wire Line
+	1850 3250 2050 3250
+Wire Notes Line
+	2050 2950 2700 2950
+Wire Wire Line
+	6650 3650 6500 3650
+Wire Wire Line
+	6500 3650 6500 4050
+Wire Wire Line
+	7600 3000 7600 4050
+Wire Wire Line
+	7250 3550 9000 3550
+Wire Wire Line
+	5750 3450 5850 3450
+Wire Wire Line
+	6150 3450 6650 3450
+Connection ~ 6250 3450
+Wire Wire Line
+	5800 3450 5800 3000
+Wire Wire Line
+	5800 3000 6450 3000
+Connection ~ 5800 3450
+Wire Wire Line
+	7600 3000 6750 3000
+Connection ~ 7600 3550
+Wire Notes Line
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+Wire Notes Line
+	8350 2850 8350 4300
+Wire Notes Line
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+Wire Wire Line
+	7600 4050 6500 4050
+Wire Wire Line
+	2350 3100 2750 3100
+Wire Wire Line
+	2350 3100 2350 3250
+Connection ~ 2500 3100
+Wire Wire Line
+	2350 3650 2350 3800
+Wire Wire Line
+	2500 3400 2500 3500
+Wire Wire Line
+	2400 3450 2500 3450
+Connection ~ 2500 3450
+Wire Wire Line
+	1900 3650 2050 3650
+Wire Wire Line
+	2350 3800 2750 3800
+Connection ~ 2500 3800
+Wire Notes Line
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+Wire Notes Line
+	2700 3950 2700 2950
+Wire Notes Line
+	2050 2950 2050 3950
+Wire Notes Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
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+Wire Wire Line
+	3650 3450 5450 3450
+Wire Wire Line
+	2950 3350 2850 3350
+Wire Wire Line
+	2950 3550 2850 3550
+Connection ~ 1750 3350
+Wire Wire Line
+	1750 3350 1900 3350
+Text Notes 1950 2900 0    39   ~ 0
+When DC coupled, sensor failure grounds output.
+Text Notes 2750 4200 0    39   ~ 0
+CMRR: >95dB\nInput Voltage Noise Density: <28nV/√Hz\nOutput Voltage Noise Density: <330nV/√Hz\nVoltage Noise (0.1-10Hz): < 0.8μV p-p\n
+Text Notes 7150 4250 0    39   ~ 0
+Offset: <125uV\nOffset Drift: <1.3uv/°C\nVoltage Noise Density: 12nV/√Hz\nVoltage Noise (0.1-10Hz): 0.2μV p-p
+Text Notes 7650 2950 0    60   ~ 0
+Antialias Filter
+$Comp
+L CONN_01X02 J504
+U 1 1 58D6DA45
+P 9200 3600
+F 0 "J504" H 9200 3750 50  0000 C CNN
+F 1 "Channel 1" V 9300 3600 50  0000 C CNN
+F 2 "" H 9200 3600 50  0001 C CNN
+F 3 "" H 9200 3600 50  0001 C CNN
+	1    9200 3600
+	1    0    0    1   
+$EndComp
+$Comp
+L GNDA #PWR076
+U 1 1 58D6DA46
+P 9000 3650
+F 0 "#PWR076" H 9000 3400 50  0001 C CNN
+F 1 "GNDA" H 9000 3500 50  0000 C CNN
+F 2 "" H 9000 3650 50  0001 C CNN
+F 3 "" H 9000 3650 50  0001 C CNN
+	1    9000 3650
+	1    0    0    -1  
+$EndComp
+Text Notes 3500 5950 0    60   ~ 0
+Problems:\n\n  - AD8622 isn't RRIO; will saturate at (V+)-1.2V.\n      Near the end of battery life; this could be less that 5V.
+$EndSCHEMATC