ltspice nmos4 and pmos4

Started by Michael Robinson in sci.electronics.design10 years ago 3 replies

I have to simulate a CMOS circuit and I am going to try it in LTSpice. The dialog box where you can put in parameters for a mos4 device has no...

I have to simulate a CMOS circuit and I am going to try it in LTSpice. The dialog box where you can put in parameters for a mos4 device has no place to enter parasitics! That means I need a subcircuit. To save time is there anyplace where I can grab subcircuits for nmos4 and pmos4 devices? That would save a lot of time, I can just change the values.


Adding a Full Selection of Parts to LTSpice

Started by Anonymous in sci.electronics.design8 years ago 2 replies

What is the most painless and straightforward way to add a full selection of "standard" compnents to the LTSpice library? For example, op...

What is the most painless and straightforward way to add a full selection of "standard" compnents to the LTSpice library? For example, op amps, regulators, CMOS IC's, switches, etc., as you would find in programs like DipTrace and EagleCad. This is the only thing I could find, but it looks a bit rough and possibly out-of-date. http://ltwiki.org/index.php5?title=Components_Library ...


cmos circuit analysis

Started by Michael Robinson in sci.electronics.design10 years ago 19 replies

I'm trying to analyze this circuit's step response. It's a current source, with the output at the drain of M14. This is a modification of an...

I'm trying to analyze this circuit's step response. It's a current source, with the output at the drain of M14. This is a modification of an earlier circuit that I wanted to improve the stability of. That circuit didn't have mosfet M16, just a wire connecting M9's drain to M15's source. It range in response to switching. It's because of huge gain in the loop that goes around M6, M11 ...


Circuit for Randomized Pulse Width Modulation

Started by Robert Martin in sci.electronics.design3 years ago 43 replies

I have a CD4060 outputting a 5Vpp 4Hz (4 hertz) square wave at 50% duty cycle. How can I randomly pulse width modulate this so that when a...

I have a CD4060 outputting a 5Vpp 4Hz (4 hertz) square wave at 50% duty cycle. How can I randomly pulse width modulate this so that when a low pass filter is added a constantly changing, "wave-like" arbitrary waveform will be produced? I would prefer analog or CMOS IC's, not a microprocessor, and minimum parts count. The "randomness" does not need to be true but only a reasonable ...


discrete JFETs vs CMOS analog switch

Started by Adam Seychell in sci.electronics.design1 year ago 29 replies

I need a switchable 0 /40dB attenuator for a 10Hz-20MHz 1Vp-p signal into a buffer amplifier (10k|3pF input loading). First I thought of using a...

I need a switchable 0 /40dB attenuator for a 10Hz-20MHz 1Vp-p signal into a buffer amplifier (10k|3pF input loading). First I thought of using a SPDT analog switch and resistor divider, but even 'low capacitance' devices come with 15~20pF capacitance on the common pin and have poor off isolation for my purpose. in --.--SW1--.--> to buffer | | 1kR | |--


RRIO LV jellybean

Started by bitrex in sci.electronics.design2 years ago 4 replies

My go-to quad lately for higher-performance low-voltage tasks has been the OPA4332. But it's a little pricey for some more pedestrian...

My go-to quad lately for higher-performance low-voltage tasks has been the OPA4332. But it's a little pricey for some more pedestrian jobs. Is there a CMOS RRIO down to ~2 volts equivalent of the LM324 that you use? The TSV99x is fast, low voltage (2.5 vs 1.8, though), and cheaper than the OPA4332. But not unity-gain stable. I'm not clear if an amp that's only stable for gain > = 4 or


new 90GSPS 8bit ADC

Started by Jamie M in sci.electronics.design8 years ago

Hi, Just saw this story today about a new high speed ADC IC from IBM: http://phys.org/news/2014-02-scientists-big.html 128GSPS at 8bits...

Hi, Just saw this story today about a new high speed ADC IC from IBM: http://phys.org/news/2014-02-scientists-big.html 128GSPS at 8bits in the 2channel variant with on die tuning: "The 64 GS/s (giga-samples per second) chips for Semtech will be manufactured at IBM's 300mm fab in East Fishkill, New York in a 32 nanometer silicon-on-insulator CMOS process and has an area of 5 mm2. ...


Topological material switched off and on for the first time

Started by Anonymous in sci.electronics.design3 years ago 3 replies

Topological material switched off and on for the first time https://www.sciencedaily.com/releases/2018/12/181210142050.htm A new study...

Topological material switched off and on for the first time https://www.sciencedaily.com/releases/2018/12/181210142050.htm A new study represents a significant advance in topological transistors and beyond-CMOS electronics. First time that the topological state in a topological insulator has been switched on and off using an electric field at room temperature.


4 ghz opamp

Started by John Larkin in sci.electronics.design6 years ago 10 replies

This is interesting: 4 GHz and CMOS inputs. http://www.linear.com/product/LTC6268-10 http://www.linear.com/docs/46371 What's amazing is...

This is interesting: 4 GHz and CMOS inputs. http://www.linear.com/product/LTC6268-10 http://www.linear.com/docs/46371 What's amazing is that it's available as a dual. Looks like they just dice up two amps in one chunk and package that. Slew rate is sorta low, so it's not good for high-swing stuff. The schematic on data sheet page 11 is interesting. -- John Larkin ...


line trigger

Started by John Larkin in sci.electronics.design5 years ago 16 replies

This is sort of goofy. Given some isolated/grounded AC voltage, 3 to maybe 12 volts RMS from a transformer, I want to derive a line trigger....

This is sort of goofy. Given some isolated/grounded AC voltage, 3 to maybe 12 volts RMS from a transformer, I want to derive a line trigger. The 1N914s represent the ESD diodes inside the Schmitt. The cap in series with the CMOS schmitt trigger looks weird, but seems OK to me. The swing at the schmitt input self-centers, from the ESD diodes conducting. Version 4 SHEET 1 1032 680 WI...


Using 4000 series logic to drive....?

Started by bitrex in sci.electronics.design4 years ago 209 replies

Another jellybean logic implementation question: I have a circuit where I'd like to to count some pulses coming out of a 4000 series IC (4011B)...

Another jellybean logic implementation question: I have a circuit where I'd like to to count some pulses coming out of a 4000 series IC (4011B) operating at 6 volts into a '163-type counter and am running into problems with the interfacing. The 4011 output in question is already fanned out into into 2 other 4000 series CMOS gates and is putting out 10% duty cycle positive-going pulses...


insane flipflop measurements

Started by John Larkin in sci.electronics.design5 years ago 46 replies

I'm doing a fast thing and thought I might go all CMOS, instead of traditional expensive ECL. We have the Fairchild NC7SV74 tiny...

I'm doing a fast thing and thought I might go all CMOS, instead of traditional expensive ECL. We have the Fairchild NC7SV74 tiny logic flipflop in stock, 16 cents each. I thought I'd play with one. Here are the rise and fall times at the Q output, 3.3 volt supply: https://dl.dropboxusercontent.com/u/53724080/Parts/Logic/NC7SV74_2.JPG That fall time is amazing, but the rise time is h...


Spurious triggering of 4013 flip-flop

Started by Terry Pinnell in sci.electronics.design3 years ago 72 replies

One of my garden lamp circuits is shown here: https://www.dropbox.com/s/10cc6lwfrsqjp68/DiningLamp-Post.jpg?raw=1 But the CMOS 4013...

One of my garden lamp circuits is shown here: https://www.dropbox.com/s/10cc6lwfrsqjp68/DiningLamp-Post.jpg?raw=1 But the CMOS 4013 flip-flop circuit suffers from occasional spurious triggering. Somehow it frequently gets activated overnight. Frustratingly I?m unable to pin it down. But I suspect it may be due to the very long wire (60 ft or so) carrying the high-going brief input signal...


Funny specification for CMOS input for microcontroller, unused inputs and slow transitions

Started by Klaus Kragelund in sci.electronics.design5 years ago 22 replies

Hey So I was just browsing a datasheet for a RX130...

Hey So I was just browsing a datasheet for a RX130 microcontroller: https://www.renesas.com/en-us/doc/products/mpumcu/rx100/r01ds0273ej0100_rx130.pdf It has a precaution note on page 115: https://dl.dropboxusercontent.com/u/44228185/CMOS_Inputs.jpg So basically in point: 1: A slowly transitioning signal can cause the device to malfunction 2: An unused input (not terminated), c...


Single Button On/Off Circuit with Delay

Started by Ricketty C in sci.electronics.design1 year ago 15 replies

I'm trying to figure out a way to design an On/Off circuit that uses very little power when off and requires holding the push button for two or...

I'm trying to figure out a way to design an On/Off circuit that uses very little power when off and requires holding the push button for two or three seconds before it accepts the change. A pair of CMOS gates/inverters can provide the low power two state circuit and a push button connected with a simple capacitor/resistor arrangement will default to off on power up and allow toggli


SPICE simulation -- how to bias a crystal oscillatoir

Started by Anonymous in sci.electronics.design6 years ago 26 replies

Could some electronics/SPICE guru please help ? I have a simple model of a quartz crystal, as used in an oscillator. With my SPICE simulation, I...

Could some electronics/SPICE guru please help ? I have a simple model of a quartz crystal, as used in an oscillator. With my SPICE simulation, I can measure both the parallel and series resonant frequencies of the "pure" crystal. However, when I attach the same crystal to a biasing circuit, and run the simulation, the output is a flat DC offset. The biasing circuit involves two CMOS(1.0u m...


AN: Spice Model Updated on my Website... Behavioral Diff Pairs

Started by Jim Thompson in sci.electronics.design6 years ago

Spice Model Updated on my Website: See B_DIFF_PAIRS.zip on the Device Models & Subcircuits Page of my website. Improved/Updated (squirmy talk...

Spice Model Updated on my Website: See B_DIFF_PAIRS.zip on the Device Models & Subcircuits Page of my website. Improved/Updated (squirmy talk for serious bug fix ;-) Parameters added to match bipolar or CMOS behavior. Please direct all questions/comments/error-reporting via the E-mail (envelope) icon on my website or via the LTspice List. .....


one-IC digital PLL?

Started by frank in sci.electronics.design6 years ago 15 replies

Hi all, I'm looking for a small-real-estate solution to generate a clock (ttl/cmos 5V) from a given quartz oscillator. The output clock I need...

Hi all, I'm looking for a small-real-estate solution to generate a clock (ttl/cmos 5V) from a given quartz oscillator. The output clock I need is 4/9 or 4/7 ratio of the original input clock. I know I can easily make a VCO/PLL solution, but the real problem is a very small space on the PCB, so I might be able to use a couple of small ICs, but probably not too much else. Input clock is < 2


Gallium Arsenide CPU's ie Cray 3 and solar panels

Started by Jamie M in sci.electronics.design6 years ago 20 replies

Hi, I was reading about the Cray 3 supercomputer from about 20 years ago, 500MHz clock with lots of small gallium arsenide die bonded...

Hi, I was reading about the Cray 3 supercomputer from about 20 years ago, 500MHz clock with lots of small gallium arsenide die bonded IC's connected together to form the processors.. I thought that GaAs was a poor material to use due to being difficult to do CMOS due to the P channel taking up 10x too much die area or something like that. Did the Cray 3 have this P channel transistor p...


CMOS op amp datasheet: Lies! All lies!

Started by Phil Hobbs in sci.electronics.design6 years ago 28 replies

So I'm just getting round to testing the super low cost front end for the cotton spark detection gizmo. Total BOM at Digikey prices (1ku)...

So I'm just getting round to testing the super low cost front end for the cotton spark detection gizmo. Total BOM at Digikey prices (1ku) is about $1.85, including about 60 cents' worth of protection circuitry. The front end amp is a TLV272IS (a splurge at 23 cents), with a couple of 100M 1206es in series for feedback. The resistor's 1-Hz Johnson noise is sqrt(200M/60.4) nV = 1.8 uV, so ...