100 meter cable charged to 500V * cable discharge test using one twisted pair cable (Hspice) * * the RJ-45 contacts are modeled as voltage controlled resistors * the timing of the physical contact mating is simulated by applying * a timing relationship on these VCR's * * the single twisted pair cable is initially charged and is open on both ends * then it is plugged in at one end (the near end) * the input contains a 1:1 transformer with a center tap. * that center tap is hooked to the common mode termination: 75 ohm in series with a 1nF cap ********************************************************************** * analysis type and options ********************************************************************** .tran 1n 10u 0 0.5n .options list node post *.options accurate .probe i(rlimit1) i(rlimit2) i(r_comterm) ********************************************************************** * differential measurements ********************************************************************** e_primary diff_primary 0 input_a input_b 1 r_diffpri diff_primary 0 1e6 e_secondary diff_secondary 0 sec1 sec2 1 r_diffsec diff_secondary 0 1e6 ********************************************************************** * initial conditions, the cable is charged up here in advance of plugging in ********************************************************************** .param init_cable_v = 500VDC .param init_common_cap_v = 0VDC * initial conditions on the twisted pair cable .ic v(farend_a) = init_cable_v .ic v(farend_b) = init_cable_v * initial conditions on the common mode termination cap .ic v(cap_term)= init_common_cap_v ********************************************************************** * common mode termination ********************************************************************** * PCB trace to the termination******** * lossy line model with length in meters, 0.0254 (meters) = 1 inch ucentertap center_tap 0 com_term 0 stripmod L=.015 * the resistive part of the termination r_comterm com_term cap_term 75 * the high voltage cap to frame ground ***** c_hi_v cap_term cap1 1000p l_cap cap1 cap2 1.5n r_cap cap2 0 0.62 * capacitor leakage r_shuntcap cap_term 0 1e8 ********************************************************************** * Simulation of plugging in the RJ-45 ********************************************************************** * the RJ-45 contacts are modeled as a voltage controlled resitor * this does not simulate any contact bounce gswitch1 input_a nearend_a VCR PWL(1) cntrl1 0 0V,100meg 1V,0.1 gswitch2 input_b nearend_b VCR PWL(1) cntrl2 0 0V,100meg 1V,0.1 * the following sources generate the timing of the two RJ-45 pins mating * here, the time difference is 5us between the first pin mating and the second pin mating * that corresponds to a difference in the RJ-45 pin lengths of about 0.1 mils (1E-4 inches) * combined with an insertion speed of 20 inches per second * the key is that for that first 5us period, only one RJ-45 pin has mated vcntrl1 cntrl1 0 pulse 0 1V 100n 0.1n 0.1n 1000u 2000u vcntrl2 cntrl2 0 pulse 0 1V 5.1u 0.1n 0.1n 1000u 2000u * trace to the XFMR ***** * lossy line model with length in meters, 0.0254 (meters) = 1 inch upri1 input_a 0 input_aa 0 stripmod L=.01 upri2 input_b 0 input_bb 0 stripmod L=.01 ********************************************************************** * the data XFMR ********************************************************************** * choose one * x_xfmr1 input_aa input_bb center_tap sec1 sec2 0 dataxfmr x_xfmr1 input_aa input_bb center_tap sec1 sec2 0 dataxfmr_no_choke * x_xfmr1 input_aa input_bb center_tap sec1 sec2 0 dataxfmr_w_choke ********************************************************************** * the secondary side of the data XFMR ********************************************************************** * terminate the secondary of the XFMR ***** * lossy line model with length in meters, 0.0254 (meters) = 1 inch uclamp1 sec1 0 sec1a 0 stripmod L=.0254 uclamp2 sec2 0 sec2a 0 stripmod L=.0254 rterm sec1a sec2a 100 * a simple voltage zener clamp on the PHY for demonstration purposes only * comment this out to see behavior without the clamp *rlimit1 sec1a clamp1a 0.1 *llimit1 clamp1a clamp1b 10n *xdiode1 0 clamp1b d1n4733 *rlimit2 sec2a clamp2a 0.1 *llimit2 clamp2a clamp2b 10n *xdiode2 0 clamp2b d1n4733 ********************************************************************** * the single twisted pair model ********************************************************************** * lossy coupled line from RLGC * length conversion: 25 feet is 300 inches, 100 meters is 3937 inches * the file: cat5_rlc.rlc contains RLGC parameters in length of inches .param cable_length = 3937 W1 N=2 nearend_a nearend_b 0 farend_a farend_b 0 RLGCfile=cat5_rlc.rlc L=cable_length * the far end of the cable is open, but we need a DC path to ground to satisfy Spice.... rplus farend_a 0 100meg rminus farend_b 0 100meg ********************************************************************** * subcircuits and models ********************************************************************** *** data transformer model without Shunt Choke *** *** from Hank Hinrichs, Pulse *** * Series Common Mode Choke .SUBCKT dataxfmr_no_choke wireside_a wireside_b wireside_centertap physide_a physide_b physide_centertap CWWCMC1 wireside_a wireside_b 3pF $ Capacitance, winding to winding LCMC1 wireside_a 17 25uH $ Open circuit inductance LLCMC1 17 18 .1uH $ Leakage inductance RCMC1 18 19 .25 $ Winding resistance LCMC2 wireside_b 20 25uH LLCMC2 20 21 .1uH RCMC2 21 22 .25 CWWCMC2 19 22 1pF K_CMC LCMC1 LCMC2 .99999 * Transformer CDS1 19 wireside_centertap 5pF $ Distributed capacitance, secondary CDS2 22 wireside_centertap 5pF LLS1 19 23 20nH $ Leakage inductance, secondary LLS2 22 24 20nH RLLS1 23 25 1.1 $ Resistance, secondary winding RLLS2 24 26 1.1 RCORE 25 26 6000 $ Core loss * Ideal center-tapped transformer with 1:1 turns ratio LSTran1 25 wireside_centertap 125uH LSTran2 wireside_centertap 26 125uH LPTran1 27 28 125uH LPTran2 28 29 125uH k_Tran1 LSTran1 LPTran1 .99999 k_Tran2 LSTran1 LPTran2 .99999 k_tran3 LSTran1 LSTran2 .99999 RPRICT 28 physide_centertap .1 .param cvalps=10pF CWW1 25 41 cvalps CWW2 26 42 cvalps RCWW1 41 27 1500 RCWW2 42 29 1500 RLLP1 27 30 1.1 RLLP2 29 31 1.1 CDP1 30 31 1.25pF LLP1 30 32 55nH LLP2 31 33 55nH CDP2 32 33 3.35pF LLPR1 32 physide_a 23nH LLPR 33 physide_b 23nH .ENDS dataxfmr_no_choke ************************************************************************** ************************************************************************** *** data transformer model with Shunt Choke *** *** from Hank Hinrichs, Pulse *** .SUBCKT dataxfmr_w_choke wireside_a wireside_b wireside_centertap physide_a physide_b physide_centertap * Shunt Choke CDSC1 wireside_a wireside_centertap 8pF $ Distributed capacitance, half winding RLSC1 wireside_a 11 .3 $ Wire resistance, " " LLSC1 11 12 .3uH $ Leakage inductance," " LSC1 12 wireside_centertap 500uH $ Open Circuit Inductance, " LSC2 wireside_centertap 14 500uH $ Parameters for the other half winding LLSC2 14 15 .3uH RLSC2 15 wireside_b .3 CDSC2 wireside_b wireside_centertap 8pF K_SC LSC1 LSC2 .99999 * Series Common Mode Choke CWWCMC1 wireside_a wireside_b 3pF $ Capacitance, winding to winding LCMC1 wireside_a 17 25uH $ Open circuit inductance LLCMC1 17 18 .1uH $ Leakage inductance RCMC1 18 19 .25 $ Winding resistance LCMC2 wireside_b 20 25uH LLCMC2 20 21 .1uH RCMC2 21 22 .25 CWWCMC2 19 22 1pF K_CMC LCMC1 LCMC2 .99999 * Transformer CDS 19 22 2.4pF $ Distributed capacitance, secondary LLS1 19 23 20nH $ Leakage inductance, secondary LLS2 22 24 20nH RLLS1 23 25 1.1 $ Resistance, secondary winding RLLS2 24 26 1.1 RCORE 25 26 6000 $ Core loss * Ideal primary side center-tapped transformer with 1:1 turns ratio LSTran 25 26 500uH LPTran1 27 28 125uH LPTran2 28 29 125uH k_Tran1 LSTran LPTran1 .99999 k_Tran2 LSTran LPTran2 .99999 RPRICT 28 physide_centertap .1 .param cvalps=10pF CWW1 25 41 cvalps CWW2 26 42 cvalps RCWW1 41 27 1500 RCWW2 42 29 1500 RLLP1 27 30 1.1 RLLP2 29 31 1.1 CDP1 30 31 1.25pF LLP1 30 32 55nH LLP2 31 33 55nH CDP2 32 33 3.35pF LLPR1 32 physide_a 23nH LLPR 33 physide_b 23nH .ENDS dataxfmr_w_choke ************************************************************************** * 10/100 data XFMR .SUBCKT dataxfmr ina inb in_ct outa outb out_ct ****************************************************** * ina_________ _______outa * ) ( * ) ( * ) ( * ) ( * ___) (___ * in_ct___| |___out_ct * |___ ___| * ) ( * ) ( * ) ( * ) ( * inb_________) (_______outb ****************************************************** *** primary L1 ina in2 20n C1 in2 in6 5.7p L3 in2 in3 40n R3 in3 in4 0.8 Lina in4 in_ct 200u Rmag1 in4 ina4 0.01 Lmag1 ina4 in_ct 220u Rinshunt in4 in8 8100 Rmag2 in8 ina8 0.01 Lmag2 in_ct ina8 220u Linb in_ct in8 200u L2 inb in6 20n L4 in6 in7 40n R4 in7 in8 0.8 *** coupling c_couple in_ct out_ct 2p K1 Lina Linb 1.0 K2 Lina Louta 1.0 K3 Lina Loutb 1.0 *** secondary Louta out9 out_ct 200u Loutb out_ct out12 200u R6 out9 out10 0.8 L5 out10 outa 40n R7 out12 out13 0.8 L6 out13 outb 40n C2 outa outb 6.4p .ends dataxfmr * pc board trace, dimensions are in meters, 1 mil = 2.54E-5 meters, or 25.4u (meters) .model stripmod U level=3 plev=1 elev=1 dlev=2 NL=1 ht=350u wd=254u + th=36u ts=812u kd=4.0 * model of pcb stackup (lossy stripline transmission line) *.model u1 u level=3 plev=1 elev=1 nl=1 *+ th=1.37mil ht=5.5mil ts=19.74mil kd=4.4 dlev=2 *+ wd=5mil xw=-0.5mil * level: 3=lossy transmission line model * plev: transmission line physical model (1=planar, 2=coax, 3=twinlead) * elev: 1=geometry, 2=precomputed caracteristics * nl: number of conductors (traces) * th: conductor thickness (1 oz copper or 0.5 oz copper) * ht: conductor hight (distance of trace above plane) * ts: distance between planes * kd: dielectric constant * dlev: 0=trace over plane (1 dialectric) * 1=microstrip, * 2=stripline, * 3=trace over plane (2 dialectrics) * wd: width of trace * xw: difference between drawn and realized trace width .alter 50 meter cable charged to 500V .param cable_length = 1968 .param init_cable_v = 500VDC .alter 25 meter cable charged to 500V .param cable_length = 984 .param init_cable_v = 500VDC .alter 100 meter cable charged to 1000V .param cable_length = 3937 .param init_cable_v = 1000VDC .alter 50 meter cable charged to 1000V .param cable_length = 1968 .param init_cable_v = 1000VDC .alter 25 meter cable charged to 1000V .param cable_length = 984 .param init_cable_v = 1000VDC .end