# Photodiode.Transimpedance.

#### Weees

##### Newbie level 6
Hello,

I am a beginner PSPICE, in simulation electrical and electronics circuits. I want to simulate a schematic with the program Micro-CAP 12. I want to look for some graphics from a photodiode PIN which is a InGaAs Photodiode IG22-Series, I want to monitor follow parameters:

responsivity (A/W) vs wavelength(nm);
dark current (A) vs reverse voltage (V);
shunt resistance vs. temperature;
detectivity vs. shunt x area;
capacitance vs. reverse voltage;
normalized response (a.u.) vs time (µs)
relative sensitivity (%) vs incident Light Level (mW)

And at the transistor BFP420 I want to monitor some graphics at the following parameters:

total power dissipation Ptot = ƒ(TS);
permissible pulse load RthJS = ƒ(tp);
collector-base capacitance Ccb= ƒ(VCB)f = 1MHz;
transition frequency fT= ƒ(IC) f = 2 GHz VCE = parameter in V;
power gain Gma, Gms, |S21|² = ƒ (f) VCE = 2 V, IC = 20 mA;
power gain Gma, Gms = ƒ (IC) VCE = 2V f = parameter in GHz;
collector-base capacitance Ccb = f (VCB) VBE = 0, f = 1MHz;
noise figure F = f (IC) VCE = 2 V, ZS = ZSopt;
noise figure F = f (IC) VCE = 2 V, f = 1.8 GHz;
I do not know how to begin. Please help me. I accept, if is necessary any simulator of circuits.Or only important electrical parameters.
I attach a electric schematic.

Thank you for understanding,

Dragos

Last edited by a moderator:

##### Full Member level 4
The biggest challenge will be to get an accurate model to carry out some
of the measurements you want to do. A number of these are largely derived
from process characterization of the devices.

I would advise, once you have your hand on the model you take a look at its
definition file to see what is covered, possibly even contact production engineer
at manufacturer to find out what parts of model are complete from the charac-
terization findings versus theoretical equation mashups.

Good luck.

Regards, Dana.

#### Weees

##### Newbie level 6
Can you help me, to get those graphics of parameters?

##### Full Member level 4
Post your Micro Cap file, there may be some other users here that can help
with various parts of the problem.

Is this a homework problem ?

Regards, Dana.

#### Weees

##### Newbie level 6
I am sorry that I answer so late. This is not a homework problem. It is a personal project. That has the role to detect the smoke, with a photodiode.