Curve tracers

Started by Phil Hobbs in sci.electronics.design10 years ago 63 replies

Hi, all--I'm looking for a curve tracer. Ideally it would be USB-powered, and come with software that would make plots and generate data...

Hi, all--I'm looking for a curve tracer. Ideally it would be USB-powered, and come with software that would make plots and generate data files. Nothing too fancy, just I_C and I_B vs V_CE and V_BE, and the equivalent for FETs. A plus would be automatic computation of beta, V_GSth, Early voltage, and even some of the DC SPICE parameters like emitter and base resistance. It would be ...


LT Spice arcs

Started by John Larkin in sci.electronics.design8 years ago 12 replies

If I select edit/draw/arc, it usually draws a circle! Or a lopsided arc. Is there a trick for drawing controllable arcs? -- John...

If I select edit/draw/arc, it usually draws a circle! Or a lopsided arc. Is there a trick for drawing controllable arcs? -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation


LT Spice noise analysis

Started by John Larkin in sci.electronics.design6 years ago 38 replies

I wonder why it requires a noiseless input source to be specified. Any why does it only analyze the noise at one node? Given that, why...

I wonder why it requires a noiseless input source to be specified. Any why does it only analyze the noise at one node? Given that, why do I have to probe that one node? -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com


new spice

Started by John Larkin in sci.electronics.design1 year ago 218 replies

https://www.linkedin.com/in/mike-engelhardt-a788a822 -- If a man will begin with certainties, he shall end with doubts, but if he will be...

https://www.linkedin.com/in/mike-engelhardt-a788a822 -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon


testing the TI switchers

Started by John Larkin in sci.electronics.design3 weeks ago 19 replies

I really like the TPS5 family of tiny little switchers, but their Spice models are, to be kind, absurd garbage. The first switcher on our board...

I really like the TPS5 family of tiny little switchers, but their Spice models are, to be kind, absurd garbage. The first switcher on our board simulates input power of 12 volts * 9 tera-amps. We're well along on pcb layout of a new delay generator, but I really want more confidence that everything will work first pass. So in parallel we're prototyping the switchers. https://www.dropbox....


LT spice component attributes

Started by John Larkin in sci.electronics.design4 years ago 4 replies

The right-click "component attribute editor" for a part has "value" and "spiceline" fields, which are not very well explained. What's...

The right-click "component attribute editor" for a part has "value" and "spiceline" fields, which are not very well explained. What's the difference? The HELP generically refers to "parameters." I understand "value" can be simply "4.7K" or some extra attributes like "vhigh=5 td=2n". What is spiceline? -- John Larkin Highland Technology, Inc picosecond timing precision...


CMRR

Started by habib in sci.electronics.design3 years ago 43 replies

Hi, I'm designing a precise Mains Energy Meter (Class 0.2). There's a mandatory requirement in the design spec * .. shall detect the...

Hi, I'm designing a precise Mains Energy Meter (Class 0.2). There's a mandatory requirement in the design spec * .. shall detect the homopolar (Phase-Neutral) current in range (10mA ... 30mA) with 10% accuracy In this Spice implementation I expected CMRR of the circuit should be 60dB or so ... When i compare V_Common_mode and Vout with FFT, the 5KHz is far that attenuation althoug...


SPICE models published

Started by Tim Williams in sci.electronics.design3 years ago 3 replies

Releasing some of my models today: https://www.seventransistorlabs.com/Modeling/index.html Tim -- Seven Transistor Labs, LLC Electrical...

Releasing some of my models today: https://www.seventransistorlabs.com/Modeling/index.html Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Design Website: https://www.seventransistorlabs.com/


Finding LTspice Models

Started by Ricky C in sci.electronics.design3 years ago 13 replies

LTspice is a nice program... well, it's ok in many respects and great in others. But it can be a PITA to find models for. I'm looking at a...

LTspice is a nice program... well, it's ok in many respects and great in others. But it can be a PITA to find models for. I'm looking at a number of possible parts to use in a new design but many of them have no spice models. I'm not so worried about finding an accurate LED model. But I'm using a Schottky diode to prevent back feeding of power through a regulator and I need a


guard ring?

Started by John Larkin in sci.electronics.design4 years ago 39 replies

I'm still iterating on my high-voltage pulse generator. Rev C looks very good. I've been pushing it up voltage and frequency (like,...

I'm still iterating on my high-voltage pulse generator. Rev C looks very good. I've been pushing it up voltage and frequency (like, 1200 volts and 4 MHz) and seeing what parts fry, and working on them. I have a dpak schottky diode in a sort of snubber place. According to Spice, it shouldn't get too hot, and it's soldered to all sorts of copper pours and thermal vias and stuff. It's an S...


LT Spice challenge

Started by John Larkin in sci.electronics.design1 year ago 33 replies

Suppose I have a circuit with 20 nodes, N1 ... N20. I want to plot the node voltages, left to right on the screen. Any ideas? Clumsy...

Suppose I have a circuit with 20 nodes, N1 ... N20. I want to plot the node voltages, left to right on the screen. Any ideas? Clumsy ways: Build an analog mux and clock it with a counter, plot with time as x-axis Push a pulse into a tapped transmission line to sequence a bunch of switches Export a file and do it in a separate program


LT5560 Mixer ??

Started by Jim Thompson in sci.electronics.design8 years ago 1 reply

Anyone know of a spice model for an LT5560 mixer... or at least some solid numbers... the datasheet is sorely lacking :-( ...

Anyone know of a spice model for an LT5560 mixer... or at least some solid numbers... the datasheet is sorely lacking :-( ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San ...


Guesstimate A Transformer

Started by Anonymous in sci.electronics.design4 years ago 14 replies

One of my useless things I think I'll throw together. An audio amp. I have transformers, audio output transformers from a tube amp that have a...

One of my useless things I think I'll throw together. An audio amp. I have transformers, audio output transformers from a tube amp that have a certain feature I need for this. This is a mobile audio amplifier. The basic configuration is shown at the end of this post in Spice. The coils, L1 and L2 are actually a center tapped winding. What I want to know is how much power dare


LT Spice resistor vs time

Started by Anonymous in sci.electronics.design3 years ago 14 replies

Is there a way to run a transient response and have a resistor value be a function of time? I tried setting a resistor value to {50000*TIME}...

Is there a way to run a transient response and have a resistor value be a function of time? I tried setting a resistor value to {50000*TIME} and it doesn't like that. I can set a bv to V=TIME and get a voltage ramp. I want a br component. I guess I could program Ohm's Law into a bi or something ugly like that. -- John Larkin Highland Technology, Inc Science tea...


OPA552 as power regulator

Started by John Larkin in sci.electronics.design4 years ago 42 replies

I need some programmable power supply rails, maybe -5 to +40 volts or so. We have some OPA552s in stock, a nice 60 volt power opamp. It's...

I need some programmable power supply rails, maybe -5 to +40 volts or so. We have some OPA552s in stock, a nice 60 volt power opamp. It's a decomp, and it will be driving a big capacitive load, so there is an oscillation hazard. One of my guys got the model from TI and kluged it into LT Spice. The symbol is ugly but it seems to work. We don't know how to make it look like a real opamp. ...


LT Spice alternate solver

Started by Anonymous in sci.electronics.design3 years ago

I have a sim that hangs up unless I use the alternate solver. Is there a directive I can put in my circuit to force that? Or is there only the...

I have a sim that hangs up unless I use the alternate solver. Is there a directive I can put in my circuit to force that? Or is there only the persistant setting in the tools/control panel menu? Good news: the latest update finally includes the LTM8078 switcher! I'm teaching it how to convert +24 into -5 and -2.5. -- John Larkin Highland Technology, Inc Science teache...


neat power parts

Started by John Larkin in sci.electronics.design3 years ago 14 replies

https://www.dropbox.com/sh/6scihn40t60qm7k/AADq46F-s7aBowSgcaVrIr_ua?dl=0 I'm still waiting for the Spice model for the 8078. I think I can...

https://www.dropbox.com/sh/6scihn40t60qm7k/AADq46F-s7aBowSgcaVrIr_ua?dl=0 I'm still waiting for the Spice model for the 8078. I think I can make it do positive to dual negative conversion. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com


PRBS in LT Spice

Started by John Larkin in sci.electronics.design10 years ago 25 replies

We are considering sending data over CAT6 twisted-pairs, from one FPGA to another at some 10s of meters distance. It might be prudent...

We are considering sending data over CAT6 twisted-pairs, from one FPGA to another at some 10s of meters distance. It might be prudent to transformer-couple the data, to avoid ground-loop common-mode hazards, and the obvious choice would be to use RJ45 connectors with built-in Ethernet magnetics. These seem to have inductance in the 400 uH range, which gives a low-end frequency response in t...


Electronic Workbench Update

Started by RST Engineering in sci.electronics.design7 years ago 29 replies

I've got an OLD copy of Electronic Workbench that jams up Windows 7 every time I use it. Is there a (preferably free or cheap)...

I've got an OLD copy of Electronic Workbench that jams up Windows 7 every time I use it. Is there a (preferably free or cheap) circuit simulator that is somewhat similar to EWB that doesn't cob up the OS? Yeah, I know SPICE does everything but it is a royal pain in the ass to use and doesn't let me do quick and dirty simulations that don't have to be down to the gnat's eyebrow. Suggesti...


Inverter H bridge question

Started by Daku in sci.electronics.design11 years ago 25 replies

Could some electronics guru please help ? I was running a SPICE simulation of an H bridge for an inverter, with 12 V DC input. The H bridge has...

Could some electronics guru please help ? I was running a SPICE simulation of an H bridge for an inverter, with 12 V DC input. The H bridge has PMOS on the high side and NMOS on the ground side. The switching works fine, and the output waveform looks exactly as it should, except that the amplitude is in the milliVolt range. I have adjusted the MOSFET sizes but that has not been very helpful. ...