schottky diode+schmitt trigger in orcad

[!! the phoenix law !!]

Hi
I wonder if any can provide me with a pspice model for RB751SL
It is a schottky diode inteded to be used with a dickson voltage doubler
you can also suggest another diode, i am still a beginner and RB751SL is just my first hit

One more thing, I need also a schmitt trigger comparator, i can't find any in orcad libraries (my simulator), actually i am not sure where to look for exactly
I would be grateful if you led some shadows

Thx guys

 

[crutschow]

Diodes of similar voltage and current ratings generally have similar characteristics for the purposes of simulation, so just find a Schottky diode model in Orcad that's close to the one you want to use.

Common digital logic Schmitt trigger ICs are the CD4093 or the CD40106. Analog circuit Schmitt triggers are commonly make by adding a small amount of positive feedback using a couple of resistors with a comparator circuit, such as the LM139 (see data sheet).

 

[!! the phoenix law !!]

thanks, this was useful
okay, can i ask how to plot the schmitt trigger hystersis characterstic ?
i mean how to simulate and confirm the circuit funcionality ?
Thanks in advance

 

[crutschow]

okay, can i ask how to plot the schmitt trigger hystersis characterstic ?
i mean how to simulate and confirm the circuit funcionality ?

One way is to input a sawtooth voltage to the input and observe the output voltage transitions. The hysteresis is the difference between the input voltage where the output changes states when the input voltage is rising, compared to the input voltage where the output changes states when the input voltage is falling.

 

[!! the phoenix law !!]

Ok, i got to be specific at this one

first, LM139 has four comparators, i need only one, is there a similar IC with a single comparator ? it MUST be CMOS implemented or at least compatible with it since my design is based on CMOS transistors, Moreover the supply voltage should be about 2 volt, the requirements are according priority

second, is there any implementation schematic for such a comparator with discrete cmos transistors ?

Thank you very much

 

[!! the phoenix law !!]

I found LMV331 (single comparator) but unfortunately it is not CMOS implemented

 

[crutschow]

Why do you think it needs to be CMOS? As long as the voltage levels are compatible you can mix CMOS with bipolar.