Version 4 SHEET 1 2548 1580 WIRE 384 -192 144 -192 WIRE 544 -192 384 -192 WIRE 912 -192 544 -192 WIRE 1040 -144 672 -144 WIRE 1152 -144 1040 -144 WIRE 1248 -144 1152 -144 WIRE 1600 -112 1456 -112 WIRE 1760 -112 1680 -112 WIRE 544 -80 544 -192 WIRE 672 -80 672 -144 WIRE 912 -80 912 -192 WIRE 1040 -80 1040 -144 WIRE 976 -64 960 -64 WIRE 992 -64 976 -64 WIRE 1616 -16 1664 -64 WIRE 1616 -16 1568 -16 WIRE 1664 -16 1616 -64 WIRE 1696 -16 1696 -32 WIRE 1696 -16 1664 -16 WIRE 608 0 592 0 WIRE 624 0 608 0 WIRE 1696 0 1696 -16 WIRE 1600 32 1504 32 WIRE 1760 32 1760 -112 WIRE 1760 32 1680 32 WIRE 1840 32 1760 32 WIRE 1952 32 1840 32 WIRE 608 48 608 0 WIRE 976 48 976 -64 WIRE 1840 48 1840 32 WIRE 384 80 384 -192 WIRE 1344 80 1296 80 WIRE 1504 80 1504 32 WIRE 1504 80 1344 80 WIRE 1248 96 1248 -144 WIRE 1248 96 1152 96 WIRE 1152 128 1152 96 WIRE 1296 128 1296 80 WIRE 608 144 608 128 WIRE 976 144 976 128 WIRE 1248 144 1248 96 WIRE 1840 144 1840 128 WIRE 336 160 256 160 WIRE 256 176 256 160 WIRE 544 224 544 16 WIRE 672 224 672 16 WIRE 672 224 544 224 WIRE 912 224 912 16 WIRE 1040 224 1040 16 WIRE 1040 224 912 224 WIRE 1296 224 1296 208 WIRE 1152 240 1152 208 WIRE 1248 240 1248 192 WIRE 1248 240 1152 240 WIRE 912 256 912 224 WIRE 1504 288 1504 80 WIRE 1600 288 1504 288 WIRE 1760 288 1680 288 WIRE 672 304 544 304 WIRE 256 336 256 256 WIRE 384 384 384 176 WIRE 544 384 544 304 WIRE 544 384 384 384 WIRE 672 384 672 304 WIRE 912 384 912 336 WIRE 912 384 672 384 WIRE 1248 384 1248 240 WIRE 1248 384 912 384 WIRE 1616 384 1664 336 WIRE 1616 384 1568 384 WIRE 1664 384 1616 336 WIRE 1696 384 1696 368 WIRE 1696 384 1664 384 WIRE 1696 400 1696 384 WIRE 800 432 592 432 WIRE 1344 432 800 432 WIRE 1456 432 1456 -112 WIRE 1456 432 1344 432 WIRE 1600 432 1456 432 WIRE 1760 432 1760 288 WIRE 1760 432 1680 432 WIRE 1840 432 1760 432 WIRE 1936 432 1840 432 WIRE 1840 448 1840 432 WIRE 384 480 384 384 WIRE 464 480 384 480 WIRE 544 480 464 480 WIRE 592 480 592 432 WIRE 544 496 544 480 WIRE 1840 544 1840 528 WIRE 544 560 544 544 WIRE 544 560 384 560 WIRE 1376 608 1248 608 WIRE 144 624 144 -112 WIRE 384 624 384 560 WIRE 384 624 144 624 WIRE 592 624 592 560 WIRE 144 656 144 624 WIRE 1872 656 1856 656 WIRE 1888 656 1872 656 WIRE 1248 672 1248 608 WIRE 1376 672 1376 608 WIRE 1872 672 1872 656 WIRE 1728 736 1712 736 WIRE 1744 736 1728 736 WIRE 1728 768 1728 736 WIRE 1248 784 1248 752 WIRE 1376 784 1376 752 WIRE 1696 784 1376 784 WIRE 1840 800 1760 800 WIRE 1872 800 1872 752 WIRE 1872 800 1840 800 WIRE 1920 800 1872 800 WIRE 1376 816 1376 784 WIRE 1696 816 1632 816 WIRE 1728 864 1728 832 WIRE 1728 864 1712 864 WIRE 1744 864 1728 864 WIRE 256 880 256 848 WIRE 800 944 800 432 WIRE 944 944 800 944 WIRE 1104 944 1024 944 WIRE 1504 944 1104 944 WIRE 1536 944 1504 944 WIRE 1632 944 1632 816 WIRE 1632 944 1616 944 WIRE 1680 944 1632 944 WIRE 1840 944 1840 800 WIRE 1840 944 1760 944 WIRE 1872 976 1856 976 WIRE 1888 976 1872 976 WIRE 256 992 256 960 WIRE 256 992 192 992 WIRE 1872 992 1872 976 WIRE 192 1024 192 992 WIRE 256 1024 256 992 WIRE 768 1040 592 1040 WIRE 960 1040 1008 992 WIRE 960 1040 768 1040 WIRE 1008 1040 960 992 WIRE 1040 1040 1040 1024 WIRE 1040 1040 1008 1040 WIRE 1728 1040 1712 1040 WIRE 1744 1040 1728 1040 WIRE 1040 1056 1040 1040 WIRE 1728 1072 1728 1040 WIRE 944 1088 800 1088 WIRE 1104 1088 1104 944 WIRE 1104 1088 1024 1088 WIRE 1376 1088 1376 896 WIRE 1696 1088 1376 1088 WIRE 1792 1104 1760 1104 WIRE 1872 1104 1872 1072 WIRE 1872 1104 1792 1104 WIRE 1920 1104 1872 1104 WIRE 800 1120 800 1088 WIRE 1696 1120 1648 1120 WIRE 256 1136 256 1104 WIRE 592 1152 592 1040 WIRE 1376 1168 1376 1088 WIRE 1728 1168 1728 1136 WIRE 1728 1168 1712 1168 WIRE 1744 1168 1728 1168 WIRE 1504 1232 1504 944 WIRE 1536 1232 1504 1232 WIRE 1648 1232 1648 1120 WIRE 1648 1232 1616 1232 WIRE 1680 1232 1648 1232 WIRE 1792 1232 1792 1104 WIRE 1792 1232 1760 1232 WIRE 592 1296 592 1232 WIRE 592 1296 576 1296 WIRE 608 1296 592 1296 WIRE 1376 1312 1376 1248 FLAG 256 848 Vcc FLAG 256 1136 Vee FLAG 192 1024 0 FLAG 144 656 0 FLAG 1296 224 0 FLAG 592 624 0 FLAG 256 336 High FLAG 608 144 Med FLAG 1728 736 Vcc FLAG 1728 1040 Vcc FLAG 1728 864 Vee FLAG 1728 1168 Vee FLAG 464 480 SenseHigh FLAG 1152 -144 SenseSwitched FLAG 1344 432 HighResult FLAG 1344 80 SwitchResult FLAG 1920 800 High FLAG 1920 1104 Med FLAG 1872 656 Vcc FLAG 1872 976 Vcc FLAG 1696 384 Vee FLAG 1568 384 High FLAG 1936 432 ADC FLAG 1840 544 0 FLAG 1696 -16 Vee FLAG 1568 -16 ForceLow FLAG 1952 32 CC FLAG 1840 144 0 FLAG 1040 1040 Vee FLAG 768 1040 ForceLow FLAG 800 1120 0 FLAG 1248 784 0 FLAG 1376 1312 0 FLAG 592 1296 Vee FLAG 976 144 Med SYMBOL voltage 256 864 R0 SYMATTR InstName V1 SYMATTR Value 5 SYMBOL voltage 256 1008 R0 SYMATTR InstName V2 SYMATTR Value 5 SYMBOL current 144 -112 R180 WINDOW 0 24 80 Left 2 WINDOW 3 -452 99 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName Iload SYMATTR Value PWL(0m 0m 20m 50m 40m 500m 60m 5A) SYMBOL res 368 464 R0 SYMATTR InstName R1 SYMATTR Value 10m SYMBOL res 528 208 R0 SYMATTR InstName R2 SYMATTR Value 220m SYMBOL res 896 240 R0 SYMATTR InstName R3 SYMATTR Value 2R2 SYMBOL nmos 336 80 R0 SYMATTR InstName M1 SYMATTR Value IRLHM620 SYMBOL nmos 592 -80 M0 SYMATTR InstName M2 SYMATTR Value IRLML6246 SYMBOL e 1296 112 R0 SYMATTR InstName E2 SYMATTR Value 20 SYMBOL e 592 464 R0 SYMATTR InstName E1 SYMATTR Value 45 SYMBOL Comparators\\LT1017 1728 800 R0 SYMATTR InstName U1 SYMBOL Comparators\\LT1017 1728 1104 R0 SYMATTR InstName U2 SYMBOL res 1856 656 R0 SYMATTR InstName R4 SYMATTR Value 3k3 SYMBOL res 1856 976 R0 SYMATTR InstName R5 SYMATTR Value 3k3 SYMBOL res 1136 112 R0 SYMATTR InstName R7 SYMATTR Value 2k2 SYMBOL res 240 160 R0 SYMATTR InstName Rg1 SYMATTR Value 1k SYMBOL sw 1696 432 R90 WINDOW 0 33 -22 VRight 2 WINDOW 3 35 139 VLeft 2 SYMATTR InstName S1A SYMATTR Value MUX SYMBOL sw 1696 288 M270 WINDOW 0 39 21 VLeft 2 WINDOW 3 38 143 VLeft 2 SYMATTR InstName S1B SYMATTR Value MUX_ SYMBOL res 1824 432 R0 SYMATTR InstName RL SYMATTR Value 10k SYMBOL res 592 32 R0 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res 960 32 R0 SYMATTR InstName R9 SYMATTR Value 10k SYMBOL sw 1696 32 R90 WINDOW 0 44 -20 VRight 2 WINDOW 3 48 128 VLeft 2 SYMATTR InstName S2A SYMATTR Value MUX SYMBOL sw 1696 -112 M270 WINDOW 0 42 24 VLeft 2 WINDOW 3 42 138 VLeft 2 SYMATTR InstName S2B SYMATTR Value MUX_ SYMBOL res 1824 32 R0 SYMATTR InstName RL1 SYMATTR Value 10k SYMBOL sw 1040 1088 R90 WINDOW 0 31 -8 VRight 2 WINDOW 3 31 141 VLeft 2 SYMATTR InstName S1 SYMATTR Value MUX SYMBOL sw 1040 944 M270 WINDOW 0 38 25 VLeft 2 WINDOW 3 36 148 VLeft 2 SYMATTR InstName S2 SYMATTR Value MUX_ SYMBOL voltage 1248 656 R0 SYMATTR InstName Vref SYMATTR Value 2.500V SYMBOL res 1360 656 R0 SYMATTR InstName R10 SYMATTR Value 910k SYMBOL res 1360 800 R0 SYMATTR InstName R11 SYMATTR Value 82k SYMBOL res 1360 1152 R0 SYMATTR InstName R12 SYMATTR Value 9k1 SYMBOL voltage 592 1136 R0 SYMATTR InstName V3 SYMATTR Value 0V SYMBOL res 1632 928 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R13 SYMATTR Value 1k SYMBOL res 1776 928 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R14 SYMATTR Value 4.7Meg SYMBOL pmos 960 16 R180 SYMATTR InstName M4 SYMATTR Value Si4433DY SYMBOL pmos 992 16 M180 SYMATTR InstName M5 SYMATTR Value Si4433DY SYMBOL res 1632 1216 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R15 SYMATTR Value 1k SYMBOL res 1776 1216 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R16 SYMATTR Value 4.7Meg SYMBOL nmos 624 -80 R0 SYMATTR InstName M3 SYMATTR Value IRLML6246 TEXT 102 -248 Left 2 !.tran 60m TEXT 864 520 Left 2 !.model MUX SW(Ron=50R Roff=10Meg Vt=5V Vh=2V)\n.model MUX_ SW(Ron=50R Roff=10Meg Vt=-5V Vh=-2V) TEXT 688 1200 Left 4 ;Low current range,\nused for <50mA\ncurrent limit TEXT 1552 -304 Left 4 ;To Current Control EA TEXT 1520 200 Left 4 ;To Current ADC TEXT 1544 -256 Left 2 ;Range switched by ForceLow input\nMay need to adjust EA compensation\nfor low & high CC ranges (use final MUX) TEXT 1504 1288 Left 2 ;Hysteresis to prevent oscillation\nRough values - will need tweaking TEXT 936 -264 Left 2 ;Use PCh for free complimentary\nbehaviour. Cgs of M5 might be\nan issue if Vcc rail has noise. TEXT 104 -328 Left 2 ;Pulse excitation: PWL(0m 0m 20m 50m 40m 500m 60m 5A)\nLow/Med boundary: SINE(50m 10m {2/60m})\nMed/High boundary: SINE(500m 50m {2/60m}) TEXT 648 472 Left 2 ;Reduced gain\nto allow 10%\nheadroom TEXT 1312 1168 VLeft 2 ;Thresholds set for\n~5% over range TEXT 1120 256 Left 2 ;Amp Zin TEXT 680 240 Left 2 ;Suggest increasing\nR2, R3 to dilute\nopamp Vos drift TEXT 416 648 Left 2 ;50mV max\nOpamp Vos ~2uV/C\nFor +-20C get +-40uV\nEqual to +-4mA drift TEXT 1256 272 Left 2 ;Allow ~10%\nheadroom TEXT 1392 608 Left 4 ;Auto Range Comparators TEXT 856 480 Left 2 ;MUX switch definitions. Fairly low Ron & leakage needed TEXT 160 -80 Left 2 ;Could flip M1 D&S to\nuse body diode to\nprotect R2, R3 etc.\n \nCheck leakage\ncurrent first! RECTANGLE Normal 2000 176 1520 -352 2 RECTANGLE Normal 2000 560 1520 176 2 RECTANGLE Normal 1136 1328 496 880 2 RECTANGLE Normal 2000 1360 1216 576 2