Confuse on simulation

[yannsun]

hi all,
I try to simulate the classic half wave rectifier circuit with one resistor and one diode by HSPICE, but the result shows voutfollows vin, i.e. there is no effect of the diode switch function during the vd variation. What i am confused and also want to know is whether HSPICE can properly simulate the diode transient characteristics, and does anyone use HSPICE, PSPICE or any other simulator program, to succeed in obtaining the diode circuit transient simulation result?
The following is the netlist sketch with diode model.

V1 vin 0 SIN 0 5 10MEG 0
D1 vin vout PDIODE
R1 vout 0 1K
.TRAN 0.5n 1u
.PROBE tran v(vout) v(vin)
.options probe

###┌┐┌┐┌┐
####└┘└┘└ =>
###┌┐┌┐┌┐
####└┘└┘└
SIN input (PUSLE input shows the similar result)

 

[FvM]

What do you mean, vout follows vin also during the negative halfwave? In this case, something would be wrong with the diode model. Generally, any SPICE variant is able to perform such simple simulations and I wouldn't expect large differences in result. What about the used diode model? If it's a breakout part, it probably has no time dependant parameters or junction capacitance. So you won't see real diode behaviour in transient analysis, just the static diode characteristics.

 

[LvW]

I am pretty sure that the "error source" is the frequency which is too high for the kind of diode you are using. The diode capacitance is responsible for this effect.
Try a frequency of 100 kHz - and you will see everything is as expected.
LvW

 

[FvM]

I guess, you're right. Actually I couldn't imagine to use a power diode in simulation at 10 MHz, but I should have known better...

 

[yannsun]

Thanks for your time, problem solved.
As a matter of fact, PDIO means P+/NWELL diode, one of the pop diode implementaion in CMOS process. Fvm, you are right, the unfinished parameter setup of diode cause the result to be wrongly full wave.