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 A4 11693 8268
encoding utf-8
Sheet 1 5
Title ""
Date "2017-03-23"
Rev "AA"
Comp ""
Comment1 ""
Comment2 ""
Comment3 ""
Comment4 ""
$EndDescr
$Sheet
S 750  950  950  750 
U 58D4647E
F0 "channel0-1" 60
F1 "channel0.sch" 60
$EndSheet
$Comp
L CONN_01X02 J101
U 1 1 58D57064
P 4350 3050
F 0 "J101" H 4350 3200 50  0000 C CNN
F 1 "External 5V Ref" V 4450 3050 50  0000 C CNN
F 2 "" H 4350 3050 50  0001 C CNN
F 3 "" H 4350 3050 50  0001 C CNN
	1    4350 3050
	-1   0    0    1   
$EndComp
$Comp
L GNDA #PWR01
U 1 1 58D5726E
P 4750 3300
F 0 "#PWR01" H 4750 3050 50  0001 C CNN
F 1 "GNDA" H 4750 3150 50  0000 C CNN
F 2 "" H 4750 3300 50  0001 C CNN
F 3 "" H 4750 3300 50  0001 C CNN
	1    4750 3300
	1    0    0    -1  
$EndComp
Wire Wire Line
	4550 3000 5150 3000
Wire Wire Line
	5150 3200 5150 3650
Wire Wire Line
	5150 3650 5850 3650
Wire Wire Line
	5850 3650 5850 3100
Wire Wire Line
	5750 3100 6150 3100
$Comp
L GNDA #PWR02
U 1 1 58D57376
P 5400 3350
F 0 "#PWR02" H 5400 3100 50  0001 C CNN
F 1 "GNDA" H 5400 3200 50  0000 C CNN
F 2 "" H 5400 3350 50  0001 C CNN
F 3 "" H 5400 3350 50  0001 C CNN
	1    5400 3350
	1    0    0    -1  
$EndComp
Text GLabel 6150 3100 2    87   Input ~ 0
Vref
Connection ~ 5850 3100
$Comp
L R R101
U 1 1 58D5759A
P 4550 4200
F 0 "R101" V 4630 4200 50  0000 C CNN
F 1 "10k" V 4550 4200 50  0000 C CNN
F 2 "" V 4480 4200 50  0001 C CNN
F 3 "" H 4550 4200 50  0001 C CNN
	1    4550 4200
	1    0    0    1   
$EndComp
$Comp
L R R102
U 1 1 58D57637
P 4550 4600
F 0 "R102" V 4630 4600 50  0000 C CNN
F 1 "10k" V 4550 4600 50  0000 C CNN
F 2 "" V 4480 4600 50  0001 C CNN
F 3 "" H 4550 4600 50  0001 C CNN
	1    4550 4600
	1    0    0    1   
$EndComp
Wire Wire Line
	4550 4350 4550 4450
Wire Wire Line
	4550 4400 5300 4400
Connection ~ 4550 4400
$Comp
L GNDA #PWR03
U 1 1 58D577C3
P 4550 4750
F 0 "#PWR03" H 4550 4500 50  0001 C CNN
F 1 "GNDA" H 4550 4600 50  0000 C CNN
F 2 "" H 4550 4750 50  0001 C CNN
F 3 "" H 4550 4750 50  0001 C CNN
	1    4550 4750
	-1   0    0    -1  
$EndComp
$Comp
L GNDA #PWR04
U 1 1 58D577F5
P 5550 4750
F 0 "#PWR04" H 5550 4500 50  0001 C CNN
F 1 "GNDA" H 5550 4600 50  0000 C CNN
F 2 "" H 5550 4750 50  0001 C CNN
F 3 "" H 5550 4750 50  0001 C CNN
	1    5550 4750
	1    0    0    -1  
$EndComp
Wire Wire Line
	5300 4600 5300 5050
Wire Wire Line
	5900 4500 6400 4500
Text GLabel 6400 4500 2    87   Input ~ 0
Vref/2
$Comp
L VBATT #PWR05
U 1 1 58D58272
P 5400 2850
F 0 "#PWR05" H 5400 2700 50  0001 C CNN
F 1 "VBATT" H 5400 3000 50  0000 C CNN
F 2 "" H 5400 2850 50  0000 C CNN
F 3 "" H 5400 2850 50  0000 C CNN
	1    5400 2850
	1    0    0    -1  
$EndComp
Wire Wire Line
	5000 3000 5000 4000
Connection ~ 5000 3000
$Comp
L AD8622 U101
U 1 1 58D5411B
P 5450 3100
F 0 "U101" H 5650 3250 50  0000 L CNN
F 1 "AD8622" H 5500 2950 50  0000 L CNN
F 2 "" H 5450 3100 50  0001 C CNN
F 3 "" H 5450 3100 50  0001 C CNN
	1    5450 3100
	1    0    0    -1  
$EndComp
Text Notes 5650 2800 0    60   ~ 0
Excitation Supply
Text Notes 5650 2850 0    39   ~ 0
Noise not critical; due to INAMP CMRR
$Comp
L AD8538 U103
U 1 1 58D54621
P 5600 4500
F 0 "U103" H 5800 4650 50  0000 L CNN
F 1 "AD8538" H 5650 4350 50  0000 L CNN
F 2 "" H 5600 4500 50  0001 C CNN
F 3 "" H 5600 4500 50  0001 C CNN
	1    5600 4500
	1    0    0    -1  
$EndComp
Wire Wire Line
	4550 4000 6150 4000
Wire Wire Line
	5550 4000 5550 4250
Wire Wire Line
	4550 4050 4550 4000
Connection ~ 5000 4000
$Comp
L CP C102
U 1 1 58D54979
P 6150 4250
F 0 "C102" H 6175 4350 50  0000 L CNN
F 1 "1µF" H 6175 4150 50  0000 L CNN
F 2 "" H 6188 4100 50  0001 C CNN
F 3 "" H 6150 4250 50  0001 C CNN
	1    6150 4250
	1    0    0    -1  
$EndComp
$Comp
L CP C103
U 1 1 58D54A48
P 6150 4750
F 0 "C103" H 6175 4850 50  0000 L CNN
F 1 "1µF" H 6175 4650 50  0000 L CNN
F 2 "" H 6188 4600 50  0001 C CNN
F 3 "" H 6150 4750 50  0001 C CNN
	1    6150 4750
	1    0    0    -1  
$EndComp
Wire Wire Line
	6150 4000 6150 4100
Connection ~ 5550 4000
Wire Wire Line
	6150 4400 6150 4600
Connection ~ 6150 4500
Wire Wire Line
	6150 4900 6150 5050
Wire Wire Line
	6150 5050 5300 5050
Text Notes 5700 3900 0    60   ~ 0
Virtual Ground
Text Notes 6500 5000 0    60   ~ 0
Chopper for increased DC accuracy\nOffset: <13uV\nDrift: 0.03uV/deg. C
Text Notes 850  6150 0    60   ~ 0
Notes:\n\nR101,R102: Resistor pack for good match
$Comp
L CONN_01X02 J102
U 1 1 58D60190
P 9950 850
F 0 "J102" H 9950 1000 50  0000 C CNN
F 1 "Battery" V 10050 850 50  0000 C CNN
F 2 "" H 9950 850 50  0001 C CNN
F 3 "" H 9950 850 50  0001 C CNN
	1    9950 850 
	-1   0    0    1   
$EndComp
$Comp
L GNDA #PWR06
U 1 1 58D6032B
P 10750 1200
F 0 "#PWR06" H 10750 950 50  0001 C CNN
F 1 "GNDA" H 10750 1050 50  0000 C CNN
F 2 "" H 10750 1200 50  0001 C CNN
F 3 "" H 10750 1200 50  0001 C CNN
	1    10750 1200
	1    0    0    -1  
$EndComp
$Comp
L VBATT #PWR07
U 1 1 58D6037B
P 10750 800
F 0 "#PWR07" H 10750 650 50  0001 C CNN
F 1 "VBATT" H 10750 950 50  0000 C CNN
F 2 "" H 10750 800 50  0000 C CNN
F 3 "" H 10750 800 50  0000 C CNN
	1    10750 800 
	1    0    0    -1  
$EndComp
Wire Wire Line
	10150 800  10750 800 
$Comp
L PWR_FLAG #FLG08
U 1 1 58D603F8
P 10750 800
F 0 "#FLG08" H 10750 875 50  0001 C CNN
F 1 "PWR_FLAG" H 10750 950 50  0000 C CNN
F 2 "" H 10750 800 50  0001 C CNN
F 3 "" H 10750 800 50  0001 C CNN
	1    10750 800 
	-1   0    0    1   
$EndComp
$Comp
L AD8622 U101
U 2 1 58D617A8
P 7400 3500
F 0 "U101" H 7600 3650 50  0000 L CNN
F 1 "AD8622" H 7450 3350 50  0000 L CNN
F 2 "" H 7400 3500 50  0001 C CNN
F 3 "" H 7400 3500 50  0001 C CNN
	2    7400 3500
	1    0    0    -1  
$EndComp
Wire Wire Line
	7100 3600 7100 4000
Wire Wire Line
	7100 4000 7800 4000
Wire Wire Line
	7800 4000 7800 3500
Wire Wire Line
	7800 3500 7700 3500
Wire Wire Line
	7100 3400 6000 3400
Wire Wire Line
	6000 3400 6000 3100
Connection ~ 6000 3100
$Comp
L VBATT #PWR09
U 1 1 58D619CB
P 7350 3250
F 0 "#PWR09" H 7350 3100 50  0001 C CNN
F 1 "VBATT" H 7350 3400 50  0000 C CNN
F 2 "" H 7350 3250 50  0000 C CNN
F 3 "" H 7350 3250 50  0000 C CNN
	1    7350 3250
	1    0    0    -1  
$EndComp
$Comp
L GNDA #PWR010
U 1 1 58D619F7
P 7350 3750
F 0 "#PWR010" H 7350 3500 50  0001 C CNN
F 1 "GNDA" H 7350 3600 50  0000 C CNN
F 2 "" H 7350 3750 50  0001 C CNN
F 3 "" H 7350 3750 50  0001 C CNN
	1    7350 3750
	1    0    0    -1  
$EndComp
Text Notes 7550 3850 0    60   ~ 0
Unused
$Comp
L C C101
U 1 1 58D61AD4
P 4750 3150
F 0 "C101" H 4775 3250 50  0000 L CNN
F 1 "10µF" H 4775 3050 50  0000 L CNN
F 2 "" H 4788 3000 50  0001 C CNN
F 3 "" H 4750 3150 50  0001 C CNN
	1    4750 3150
	1    0    0    -1  
$EndComp
Wire Wire Line
	4550 3100 4550 3300
Wire Wire Line
	4550 3300 4750 3300
Connection ~ 4750 3000
$Comp
L C C104
U 1 1 58D627F1
P 10350 950
F 0 "C104" H 10375 1050 50  0000 L CNN
F 1 "1µF" H 10375 850 50  0000 L CNN
F 2 "" H 10388 800 50  0001 C CNN
F 3 "" H 10350 950 50  0001 C CNN
	1    10350 950 
	1    0    0    -1  
$EndComp
Wire Wire Line
	10150 900  10150 1200
Wire Wire Line
	10150 1200 10750 1200
Connection ~ 10350 800 
$Comp
L PWR_FLAG #FLG011
U 1 1 58D692F1
P 4600 3000
F 0 "#FLG011" H 4600 3075 50  0001 C CNN
F 1 "PWR_FLAG" H 4600 3150 50  0000 C CNN
F 2 "" H 4600 3000 50  0001 C CNN
F 3 "" H 4600 3000 50  0001 C CNN
	1    4600 3000
	1    0    0    -1  
$EndComp
Connection ~ 4600 3000
$Comp
L PWR_FLAG #FLG012
U 1 1 58D697E5
P 10750 1200
F 0 "#FLG012" H 10750 1275 50  0001 C CNN
F 1 "PWR_FLAG" H 10750 1350 50  0000 C CNN
F 2 "" H 10750 1200 50  0001 C CNN
F 3 "" H 10750 1200 50  0001 C CNN
	1    10750 1200
	1    0    0    -1  
$EndComp
Wire Wire Line
	10350 1200 10350 1100
Connection ~ 10350 1200
$Sheet
S 750  1850 950  750 
U 58D6CBCD
F0 "channel2-3" 60
F1 "channel2.sch" 60
$EndSheet
$Sheet
S 750  2750 950  750 
U 58D6D2D8
F0 "channel4-5" 60
F1 "channel4.sch" 60
$EndSheet
$Sheet
S 750  3650 950  800 
U 58D6D794
F0 "channel6-7" 60
F1 "channel6.sch" 60
$EndSheet
$EndSCHEMATC