Please help simulating this preamplifier on ltspice

[neazoi]

Can you please help me simulate this preamplifier in ltspice?
It is from the page BFG135a BJT by Infineon (qsl.net)
But I do not have a model for this Infineon BFG135A
Thanks

 

[barry]

Here's your spice model. Maybe if you knew how to do an internet search you could have spent 30 seconds and found it, too!

Search | NXP Semiconductors

 

[neazoi]

Here's your spice model. Maybe if you knew how to do an internet search you could have spent 30 seconds and found it, too!

Search | NXP Semiconductors

Thanks for the link.
But what is an s2p file, this is not an ltspice file?
And I said Infineon not NXP, there are differences between the 2 devices. Read the question carefully please.

 

[FvM]

And I said Infineon not NXP, there are differences between the 2 devices. Read the question carefully please.

BFG135A has been discontinued by Infoneon more than 10 years ago. Be happy if you find a SPICE model of this or a similar transistor at all.

If the NXP model is s2p (table of s-parameters) it can't be used in SPICE simulator. According to discussions in LTspice user group, there has been at least a SPICE model of the Philips/NXP type available.

--- Updated Mar 18, 2021 ---

It's a BFR134A model with a package subcircuit

https://www.nxp.com/downloads/en/spice-model/spice_BFG135.prm

 

[neazoi]

BFG135A has been discontinued by Infoneon more than 10 years ago. Be happy if you find a SPICE model of this or a similar transistor at all.

If the NXP model is s2p (table of s-parameters) it can't be used in SPICE simulator. According to discussions in LTspice user group, there has been at least a SPICE model of the Philips/NXP type available.

--- Updated Mar 18, 2021 ---

It's a BFR134A model with a package subcircuit

http://www.nxp.com/downloads/en/spice-model/spice_BFG135.prm

All right, thanks.
I think this will do, I have not tested it yet
**broken link removed**

--- Updated Mar 18, 2021 ---

All right, thanks.
I think this will do, I have not tested it yet
**broken link removed**

I imported it but it has some zero values. Should I worry on it?

 

[mtwieg]

I wouldn't worry about the Vceo and Ic parameters, those are max ratings for the device which aren't relevant for simulation purposes. Most third party models won't define them, which results in LTspice displaying them as zero.

 

[neazoi]

I wouldn't worry about the Vceo and Ic parameters, those are max ratings for the device which aren't relevant for simulation purposes. Most third party models won't define them, which results in LTspice displaying them as zero.

Thanks very much for this information, it is goot to know.

But if you measure the collector currents on LTSPICE and they exceed the Ic of the device, then you do have a problem don't you? So at your final design you should check if the collector currents are exceeded.
Do I get this right?

 

[crutschow]

But if you measure the collector currents on LTSPICE and they exceed the Ic of the device, then you do have a problem don't you?

Yes.
Most SPICE simulators do not monitor the maximum current or voltage ratings of devices, so it's up to you to determine that they remain below the device limits

 

[vfone]

Here is the LTspice model for BFG135 which I am using (is from NXP and not from Siemens as the one above):

.model BFG135 NPN(IS = 6.26489E-015 BF = 1.42485E+002 NF = 1.00616E+000 VAF = 4.48500E+001 IKF = 4.47193E+000 ISE = 3.79274E-013 NE = 2.07719E+000 BR = 9.14350E+000 NR = 1.05535E+000 VAR = 3.00000E+000 IKR = 3.62503E-002 ISC = 8.32089E-017 NC = 1.03925E+000 RB = 4.00000E+000 IRB = 1.00000E-006 RBM = 4.00000E+000 RE = 1.19858E+000 RC = 1.00000E+000 EG = 1.11000E+000 XTI = 3.00000E+000 CJE = 6.93680E-012 VJE = 6.00000E-001 MJE = 4.07326E-001 TF = 1.11019E-011 XTF = 5.41522E+001 VTF = 5.75002E+000 ITF = 9.98036E-001 PTF = 0.0000 CJC = 2.17679E-012 VJC = 2.78142E-001 MJC = 1.72323E-001 mfg=NXP)

 

[BigBoss]

LTSPICE is not an appropriate simulator for RF Circuits.I suggest you to use QUCS for that kind of RF Experiments.
Also, your circuit is not so good, Gain Deviation is huge.

 

[neazoi]

Thanks all!
My BFR92 RF amplifier collector current is like shown. From the datasheet, the Ic (DC) for the device is 25mA. But the collector current here varies from 8mA to 21.5mA (AC).

Would this be safe for the device (as the average current is lower) or not?

 

[BigBoss]

Average Current is taken into account.