* Z:\home\khalils\Downloads\files\data\raw_asc\0b43d0201757_rc_sensor_v7.asc
* Generated by LTspice 26.0.1 for Windows.
* Ref clock ~0.5..1.5 MHz 3.3V
* Phase Shift Theremin Sensor
* ESD protection SP721
* Calibration: with hand FAR from antenna,\nchoose FREF so that OUT is in 1..1.5V range
* Simulate for hand C from 0 to 3pF with 0.1pF step
* Library below included based on ModelFile attribute of instance XU2, XU1 (C:\users\khalils\AppData\Local\LTspice\lib\sym\Misc\NE555.asy)
Cant1 ANT2 0 8pF
C7 ANT 0 1.5pF
V1 COM 0 6V
XU1 0 FREF OUT2 COM N006 ANT2 ANT2 COM NE555 ;pnba GND)TRIG)OUT)RST)CV)THRS)DIS)Vcc
D3 ANT COM D
Q1 N004 0 COM 0 2N3906
R2 ANT2 COM 500000
Chand ANT 0 {Chand}
Q2 N005 N003 N002 0 2N3906
R4 0 N004 1500
Chand1 ANT2 0 {Chand}
C6 COM ANT 1.5pF
C2 N006 0 1nF
D4 0 ANT D
Cant ANT 0 8pF
R3 ANT2 N005 20000
R5 N002 COM 200000
XU2 0 FREF OUT COM N001 ANT ANT COM NE555 ;pnba GND)TRIG)OUT)RST)CV)THRS)DIS)Vcc
R6 FREF N003 200000
R1 COM ANT 330000
C1 N001 0 1nF
V2 FREF 0 PULSE(0 6 0 0.00000001 0.00000001 0.0000045 0.000005)
.model D D
.lib C:\users\khalils\AppData\Local\LTspice\lib\cmp\standard.dio
.model NPN NPN
.model PNP PNP
.lib C:\users\khalils\AppData\Local\LTspice\lib\cmp\standard.bjt
.tran 0 0.000333 0.0003 0.000000001 startup
.step param Chand list 0pF 0.1pF 0.2pF 0.3pF 0.4pF 0.5pF 0.6pF 0.7pF 0.8pF 0.9pF 1pF 1.1pF 1.2pF 1.3pF 1.4pF 1.5pF
.MEAS TRAN res1 FIND V(out) AT=1m
.lib NE555.sub
.backanno
.end

* LTspice schematic (.asc):
Version 4
SHEET 1 3724 1748
WIRE 1744 -96 1744 -160
WIRE 1744 -96 1696 -96
WIRE 224 -48 192 -48
WIRE 1696 -48 1696 -96
WIRE 1744 -48 1744 -96
WIRE 48 -16 48 -64
WIRE 1696 48 1696 16
WIRE 1744 48 1744 16
WIRE 1744 48 1696 48
WIRE 1824 48 1744 48
WIRE 1696 80 1696 48
WIRE 1744 80 1744 48
WIRE 48 96 48 64
WIRE 192 112 192 -48
WIRE 1696 176 1696 144
WIRE 1744 176 1744 144
WIRE 1744 176 1696 176
WIRE 192 224 192 192
WIRE 1744 224 1744 176
WIRE 848 416 784 416
WIRE 1136 416 1072 416
WIRE 848 480 432 480
WIRE 1184 480 1072 480
WIRE 1296 480 1184 480
WIRE 1440 480 1376 480
WIRE 848 544 432 544
WIRE 1184 544 1184 480
WIRE 1184 544 1072 544
WIRE 1600 544 1600 464
WIRE 1600 544 1184 544
WIRE 1680 544 1600 544
WIRE 848 608 784 608
WIRE 1120 608 1072 608
WIRE 1600 624 1600 544
WIRE 1680 624 1680 544
WIRE 1120 640 1120 608
WIRE 1120 736 1120 704
WIRE 1600 752 1600 688
WIRE 1680 752 1680 688
WIRE 1504 1072 1504 992
WIRE 2160 1184 2160 1136
WIRE 1504 1248 1504 1152
WIRE 656 1296 560 1296
WIRE 1440 1296 736 1296
WIRE 1296 1328 1296 1120
WIRE 2160 1328 2160 1280
WIRE 848 1392 784 1392
WIRE 1136 1392 1072 1392
WIRE 1504 1392 1504 1344
WIRE 560 1456 560 1296
WIRE 560 1456 432 1456
WIRE 848 1456 560 1456
WIRE 1296 1456 1296 1408
WIRE 1296 1456 1072 1456
WIRE 2160 1472 2160 1408
WIRE 848 1520 432 1520
WIRE 1296 1520 1296 1456
WIRE 1296 1520 1072 1520
WIRE 1504 1520 1504 1472
WIRE 1504 1520 1296 1520
WIRE 1680 1520 1680 1440
WIRE 1680 1520 1504 1520
WIRE 1760 1520 1680 1520
WIRE 848 1584 784 1584
WIRE 1120 1584 1072 1584
WIRE 1680 1600 1680 1520
WIRE 1760 1600 1760 1520
WIRE 1120 1616 1120 1584
WIRE 1120 1712 1120 1680
WIRE 1680 1728 1680 1664
WIRE 1760 1728 1760 1664
IOPIN 224 -48 Out
IOPIN 432 480 In
IOPIN 432 1456 In
SYMBOL res 2176 1424 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R4
SYMATTR Value 1500
SYMBOL pnp 1440 1344 M180
SYMATTR InstName Q2
SYMATTR Value 2N3906
SYMBOL voltage 192 96 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value PULSE(0 6 0 0.00000001 0.00000001 0.0000045 0.000005)
SYMBOL res 1520 1488 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R3
SYMATTR Value 20000
SYMBOL NE555 960 1488 R0
SYMATTR InstName U1
SYMBOL cap 1664 624 R0
SYMATTR InstName Chand
SYMATTR Value {Chand}
SYMBOL pnp 2096 1280 M180
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL cap 1728 80 R0
SYMATTR InstName C7
SYMATTR Value 1.5pF
SYMBOL res 1312 1424 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R2
SYMATTR Value 500000
SYMBOL voltage 48 -32 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 6V
SYMBOL diode 1712 144 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D4
SYMBOL NE555 960 512 R0
SYMATTR InstName U2
SYMBOL res 1392 464 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 330000
SYMBOL res 640 1312 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R6
SYMATTR Value 200000
SYMBOL diode 1712 16 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D3
SYMBOL cap 1584 624 R0
SYMATTR InstName Cant
SYMATTR Value 8pF
SYMBOL cap 1664 1600 R0
SYMATTR InstName Cant1
SYMATTR Value 8pF
SYMBOL cap 1728 -48 R0
SYMATTR InstName C6
SYMATTR Value 1.5pF
SYMBOL cap 1104 1616 R0
SYMATTR InstName C2
SYMATTR Value 1nF
SYMBOL cap 1104 640 R0
SYMATTR InstName C1
SYMATTR Value 1nF
SYMBOL cap 1744 1600 R0
SYMATTR InstName Chand1
SYMATTR Value {Chand}
SYMBOL res 1520 1168 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R5
SYMATTR Value 200000
FLAG 48 96 0
FLAG 224 -48 FREF
FLAG 192 224 0
FLAG 1600 464 ANT
FLAG 1600 752 0
FLAG 1680 752 0
FLAG 432 480 FREF
FLAG 48 -64 COM
FLAG 1744 224 0
FLAG 1744 -160 COM
FLAG 1824 48 ANT
FLAG 1136 416 COM
FLAG 784 416 0
FLAG 784 608 COM
FLAG 1120 736 0
FLAG 1440 480 COM
FLAG 432 544 OUT
FLAG 1680 1440 ANT2
FLAG 1680 1728 0
FLAG 1760 1728 0
FLAG 432 1456 FREF
FLAG 1136 1392 COM
FLAG 784 1392 0
FLAG 784 1584 COM
FLAG 1120 1712 0
FLAG 432 1520 OUT2
FLAG 2160 1472 0
FLAG 2160 1136 COM
FLAG 2096 1232 0
FLAG 1504 992 COM
FLAG 1296 1120 COM
TEXT 32 -304 Left 2 !.tran 0 0.000333 0.0003 0.000000001 startup
TEXT 32 -272 Left 2 !.step param Chand list 0pF 0.1pF 0.2pF 0.3pF 0.4pF 0.5pF 0.6pF 0.7pF 0.8pF 0.9pF 1pF 1.1pF 1.2pF 1.3pF 1.4pF 1.5pF\n.MEAS TRAN res1 FIND V(out) AT=1m
TEXT 328 -48 Left 2 ;Ref clock ~0.5..1.5 MHz 3.3V
TEXT 32 -368 Left 4 ;Phase Shift Theremin Sensor
TEXT 1952 -200 Left 2 ;ESD protection SP721
TEXT 328 -8 Left 2 ;Calibration: with hand FAR from antenna,\nchoose FREF so that OUT is in 1..1.5V range
TEXT 40 -208 Left 2 ;Simulate for hand C from 0 to 3pF with 0.1pF step