Version 4 SHEET 1 1492 1088 WIRE -416 64 -496 64 WIRE -352 64 -416 64 WIRE 32 64 -352 64 WIRE 560 64 160 64 WIRE -352 80 -352 64 WIRE -496 96 -496 64 WIRE 32 96 32 64 WIRE 160 96 160 64 WIRE -416 112 -416 64 WIRE -64 160 -352 160 WIRE 560 160 560 64 WIRE 560 160 256 160 WIRE -352 176 -352 160 WIRE -496 208 -496 176 WIRE -416 208 -416 176 WIRE -240 240 -256 240 WIRE -160 240 -176 240 WIRE -64 240 -80 240 WIRE 288 240 256 240 WIRE 384 240 288 240 WIRE 448 240 384 240 WIRE 560 240 560 160 WIRE 560 240 528 240 WIRE 656 240 560 240 WIRE 752 240 656 240 WIRE 848 240 752 240 WIRE -352 256 -352 240 WIRE 288 256 288 240 WIRE 384 256 384 240 WIRE 752 256 752 240 WIRE 848 256 848 240 WIRE 560 272 560 240 WIRE -208 320 -256 320 WIRE -64 320 -128 320 WIRE 288 320 256 320 WIRE 384 336 384 320 WIRE 656 336 656 240 WIRE 752 352 752 320 WIRE 848 352 848 336 WIRE -64 400 -96 400 WIRE 336 400 256 400 WIRE 384 400 336 400 WIRE 496 400 464 400 WIRE 560 400 560 352 WIRE 560 400 496 400 WIRE 560 416 560 400 WIRE 96 464 96 448 WIRE 560 512 560 496 WIRE -96 544 -96 400 WIRE 656 544 656 416 WIRE 656 544 -96 544 FLAG 384 336 0 FLAG 752 352 0 FLAG 560 512 0 FLAG -256 240 0 FLAG -496 208 0 FLAG 96 464 0 FLAG 848 352 0 FLAG -256 320 0 FLAG -352 256 0 FLAG 848 240 OUT FLAG -496 64 IN FLAG -416 208 0 FLAG 496 400 A FLAG 336 400 B SYMBOL ind 432 256 R270 WINDOW 0 32 56 VTop 0 WINDOW 3 5 56 VBottom 0 SYMATTR InstName L1 SYMATTR Value 4.7µ SYMATTR SpiceLine Rpar=2K SYMBOL schottky 368 320 M180 WINDOW 0 28 62 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D1 SYMATTR Value MBRS340 SYMATTR Description Diode SYMATTR Type diode SYMBOL cap 736 256 R0 SYMATTR InstName C1 SYMATTR Value 22µ SYMBOL voltage -496 80 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 11.5 SYMBOL res 544 256 R0 SYMATTR InstName R1 SYMATTR Value 97.6K SYMATTR SpiceLine tol=1 pwr=0.1 SYMBOL res 544 400 R0 SYMATTR InstName R2 SYMATTR Value 100K SYMBOL cap 272 256 R0 WINDOW 3 30 49 Left 0 SYMATTR Value .47µ SYMATTR InstName C2 SYMBOL cap -176 224 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C3 SYMATTR Value 330p SYMBOL res -64 224 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R3 SYMATTR Value 16.2K SYMBOL PowerProducts\\LT3481 96 288 R0 SYMATTR InstName U1 SYMBOL res -112 304 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R5 SYMATTR Value 60.4K SYMBOL res 640 320 R0 SYMATTR InstName R6 SYMATTR Value 100K SYMBOL res -368 64 R0 SYMATTR InstName R4 SYMATTR Value 100K SYMBOL cap -368 176 R0 SYMATTR InstName C4 SYMATTR Value .1µ SYMBOL res 832 240 R0 SYMATTR InstName R7 SYMATTR Value 1.65 SYMBOL cap -432 112 R0 SYMATTR InstName C5 SYMATTR Value 10µ SYMATTR SpiceLine V=25 Irms=0 Rser=0.001 MTBF=0 Lser=0 mfg="TDK" pn="C575OX7RIE106M" type="X7R" ppPkg=1 SYMBOL VOLTAGE 480 400 R90 WINDOW 0 -32 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName V2 SYMATTR Value SINE(0 1m {Freq}) TEXT -448 -176 Left 0 !.tran 0 2.4m 1.4m startup TEXT 88 40 Bottom 0 ;LT3481 - 2A, 36V switching regulator with 50uA quiescent current\nInput: 24V Output: 2.5V@2A TEXT 160 -392 Left 0 !.param Freq=100K ; iterate frequency until Gain_dB is close to zero dB.\n*.save V(a) V(b) ; I(L1) ; don't save extra waveform data\n.option plotwinsize=0 ; turn off waveform compression for better accuracy.\n.option option_angle=degrees\n \n.measure Aavg avg V(a)\n.measure Bavg avg V(b)\n.measure Are avg (V(a)-Aavg)*cos(360*time*Freq)\n.measure Aim avg -(V(a)-Aavg)*sin(360*time*Freq)\n.measure Bre avg (V(b)-Bavg)*cos(360*time*Freq)\n.measure Bim avg -(V(b)-Bavg)*sin(360*time*Freq)\n.measure Gain_dB param 20*log10(hypot(Are,Aim) / hypot(Bre,Bim))\n.measure Phase param mod(atan2(Aim, Are) - atan2(Bim, Bre)+180,360)-180 TEXT -448 -144 Left 0 ;.options plotwinsize=0 TEXT 160 -432 Left 0 !.step param freq list 10k 20k 50k 100k