Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
jlarkin@highlandsniptechnology.com wrote:
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
Haven't run into that one for a built-in LTspice model. Maybe it's one
of the post-Engelhardt ones.
Do they have a PSPICE model? If so, it could maybe be fixed with a >search+replace.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
Or a 1-ps transmission line--duelling bugs!
Cheers
Phil Hobbs
On Sat, 28 May 2022 09:32:41 -0700, jlarkin@highlandsniptechnology.com
wrote:
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
Assuming that's really the problem:
You can create a node that serves as YOUR ground. Call in GND or
whatever. If there are 2xmodels with internal common nodes, I
don't think you can isolate between them.
I'd consult LTspice@groups.io .
I generally don't use their models, unless they serve as equivalents
to more generic devices or do somethging unique that justifies
cost of real part use.
RL
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
On Sat, 28 May 2022 09:32:41 -0700,
jlarkin@highlandsniptechnology.com wrote:
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
Assuming that's really the problem:
You can create a node that serves as YOUR ground. Call in GND or
whatever. If there are 2xmodels with internal common nodes, I don't
think you can isolate between them.
I'd consult LTspice@groups.io .
I generally don't use their models, unless they serve as equivalents
to more generic devices or do somethging unique that justifies cost
of real part use.
On Sat, 28 May 2022 18:25:49 -0400, Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote:
jlarkin@highlandsniptechnology.com wrote:
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
Haven't run into that one for a built-in LTspice model. Maybe it's one
of the post-Engelhardt ones.
Do they have a PSPICE model? If so, it could maybe be fixed with a >>search+replace.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
Or a 1-ps transmission line--duelling bugs!
Cheers
Phil Hobbs
That's a neat idea. A txline is a DC-coupled 1:1 transformer.
On Sat, 28 May 2022 16:20:48 -0700, jlarkin@highlandsniptechnology.com
wrote:
On Sat, 28 May 2022 18:25:49 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
jlarkin@highlandsniptechnology.com wrote:
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
Haven't run into that one for a built-in LTspice model. Maybe it's one
of the post-Engelhardt ones.
Do they have a PSPICE model? If so, it could maybe be fixed with a
search+replace.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
Or a 1-ps transmission line--duelling bugs!
Cheers
Phil Hobbs
That's a neat idea. A txline is a DC-coupled 1:1 transformer.
You'll have the same issues placing digital logic on flying
nodes.
RL
On Sat, 28 May 2022 16:20:48 -0700, jlarkin@highlandsniptechnology.com
wrote:
On Sat, 28 May 2022 18:25:49 -0400, Phil Hobbs >><pcdhSpamMeSenseless@electrooptical.net> wrote:
jlarkin@highlandsniptechnology.com wrote:
Some LT Spice models have invisible internal nodes that are hard
ground. So you can't float them off ground.
LTC4444 mosfet driver for example, half-bridge with + and - power
rails. Bummer.
Haven't run into that one for a built-in LTspice model. Maybe it's one >>>of the post-Engelhardt ones.
Do they have a PSPICE model? If so, it could maybe be fixed with a >>>search+replace.
I'll just fake the gate driver with a couple of BVs. That will run
faster anyhow.
I guess I could run the 4444 grounded and AC couple into the gates
with DC restore. Lotta hassle.
Or a 1-ps transmission line--duelling bugs!
Cheers
Phil Hobbs
That's a neat idea. A txline is a DC-coupled 1:1 transformer.
You'll have the same issues placing digital logic on flying
nodes.
RL
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