LTspice .tran difficulty

[dg]

I am having difficulty performing a transient analysis of 2N2222
phillips transistor (provided by LTspice). This is my 1st time using
LTspice ...i successfully simulated the I-V curves and load line of
the transistor with a DC sweep but doing the transient has been
baffling. I put a similar circuit in ADS and it worked as expected.
Does anyone have any ideas? The netlist is below.

Cheerz
Deji

-----------spice netlist --------------
* C:\Program Files\LTC\SwCADIII\dejia\CE_amp_small_signal.asc
Q1 Vo N001 0 0 2N2222
Vcc N002 0 5
R1 N002 Vo 1000
Vin N001 0 SINE(0.68071 0.1 10M 10n)
..model NPN NPN
..model PNP PNP
..lib C:\Program Files\LTC\SwCADIII\lib\cmp\standard.bjt
..tran 0 1000n 0n 1n
..backanno
..end

 

[Mike Engelhardt]

Deji,

I am having difficulty performing a transient analysis of 2N2222
phillips transistor (provided by LTspice). This is my 1st time using
LTspice ...i successfully simulated the I-V curves and load line of
the transistor with a DC sweep but doing the transient has been
baffling. I put a similar circuit in ADS and it worked as expected.
Does anyone have any ideas? The netlist is below.

-----------spice netlist --------------
* C:\Program Files\LTC\SwCADIII\dejia\CE_amp_small_signal.asc
Q1 Vo N001 0 0 2N2222
Vcc N002 0 5
R1 N002 Vo 1000
Vin N001 0 SINE(0.68071 0.1 10M 10n)
.model NPN NPN
.model PNP PNP
.lib C:\Program Files\LTC\SwCADIII\lib\cmp\standard.bjt
.tran 0 1000n 0n 1n
.backanno
.end

The "10M" for the frequency of the sine wave is understood as
10 milliHertz. If you change it to "10Meg", you'll probably get
want you meant.

--Mike

 

[dg]

Thanks a lot Mike. That FIXED the problem!!!! I had thought that M and
G prefixes meant Mega and Giga in spice. i may have to double-check
that.
Deji

"Mike Engelhardt" <nospam@spam.org> wrote in message news:<zebMc.426$NO.51@newssvr27.news.prodigy.com>...

Deji,

I am having difficulty performing a transient analysis of 2N2222
phillips transistor (provided by LTspice). This is my 1st time using
LTspice ...i successfully simulated the I-V curves and load line of
the transistor with a DC sweep but doing the transient has been
baffling. I put a similar circuit in ADS and it worked as expected.
Does anyone have any ideas? The netlist is below.

-----------spice netlist --------------
* C:\Program Files\LTC\SwCADIII\dejia\CE_amp_small_signal.asc
Q1 Vo N001 0 0 2N2222
Vcc N002 0 5
R1 N002 Vo 1000
Vin N001 0 SINE(0.68071 0.1 10M 10n)
.model NPN NPN
.model PNP PNP
.lib C:\Program Files\LTC\SwCADIII\lib\cmp\standard.bjt
.tran 0 1000n 0n 1n
.backanno
.end

The "10M" for the frequency of the sine wave is understood as
10 milliHertz. If you change it to "10Meg", you'll probably get
want you meant.

--Mike

 

[Mike Engelhardt]

Deji,

Thanks a lot Mike. That FIXED the problem!!!! I had
thought that M and G prefixes meant Mega and Giga in
spice. i may have to double-check that.

G does mean Giga, as M should mean Mega, but SPICE is
case insensitive(and predates the convention that
metric multipliers greater than 1 should all start
with a capital letter so KHz is correct instead of kHz)
so Meg is used to mean Mega and m(or M) is milli.

--Mike

 

[Paul Burridge]

On Fri, 23 Jul 2004 22:36:02 GMT, "Mike Engelhardt" <nospam@spam.org>
wrote:

Deji,

Thanks a lot Mike. That FIXED the problem!!!! I had
thought that M and G prefixes meant Mega and Giga in
spice. i may have to double-check that.

G does mean Giga, as M should mean Mega, but SPICE is
case insensitive(and predates the convention that
metric multipliers greater than 1 should all start
with a capital letter so KHz is correct instead of kHz)
so Meg is used to mean Mega and m(or M) is milli.

Happily, (as you will know!) One can simply use exponents instead, for
the avoidance of doubt.
--

"What is now proved was once only imagin'd." - William Blake, 1793.