Quantization and sample/hold in spice

Started by Klaus Kragelund in sci.electronics.design3 years ago 19 replies

Hi I need to introduce and error in a signal, both quantization and sample/hold Sofar I have done it by placing an opamp based sample/hold...

Hi I need to introduce and error in a signal, both quantization and sample/hold Sofar I have done it by placing an opamp based sample/hold followed by a 8bit ADC (ADC8break) and a 8 bit DAC (DAC8break) But it doesn't feel right to use that much circuitry just to simulate an error in the system Anyone know if it can be done with ABM blocks? (sample and hold can be done with a zero order...


low pass filter in PC soundcard?

Started by Rob in sci.electronics.design5 years ago 20 replies
DAC

When looking at the output of a cheap C-Media CMI8768 based soundcard (one of those tiny PCI-X cards that hold barely more than the chip, a...

When looking at the output of a cheap C-Media CMI8768 based soundcard (one of those tiny PCI-X cards that hold barely more than the chip, a couple of output series caps and the connectors) I noticed there is no low-pass filtering of the DAC output. The output when sending a sinewave is a staircase. The samplerate was set to 48000, 96000 also tried with similar effect. Of course, when the...


LTspice simulation is taking too long to run

Started by MUHAMMAD FAHAD BHUTTA in sci.electronics.design5 years ago 11 replies

Greetings people ! So lately, I have been working on my Sigma Delta ADC and before going advance, I wanted to have a base model WORKING (1ST...

Greetings people ! So lately, I have been working on my Sigma Delta ADC and before going advance, I wanted to have a base model WORKING (1ST ORDER, 3 bit digital output) . The circuit is quite simple. Input (x) -> Difference Amplifier -> Integrator (op-amp) -> Quantizer-> Encoder -> 3-bit Output (Y) -> Feedback DAC to the non-inverting pin of Difference Amplifier (I am using I


SainSmart relay board

Started by Paul Colby in sci.electronics.design5 years ago 9 replies
DAC

I'm trying to switch two 24 volt coaxial switches using a LabJack U6. I bought a sainsmart solid state relay board rated for 240AC @ 2A under...

I'm trying to switch two 24 volt coaxial switches using a LabJack U6. I bought a sainsmart solid state relay board rated for 240AC @ 2A under the (wrong?) assumption that it should have no issue with switching 24VDC. I'm using the VS output of the LabJack (4.9V) to power the input side of the relay board. I'm switching the logic inputs using the DAC 4.8 - 0 outputs (assuming the 3.3V l...


Frequency Detection Suggestions

Started by Bradley Kimbrough in sci.electronics.design4 years ago 12 replies

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a...

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a beat frequency between the modes. The beat frequency is 450-600 MHz and is sensed from the waste beam at the back of the laser tube. For a prototype I used an amplified moderately high speed Si detector that fed into a 12 bit 125 MSPS DAC. T


USB thing for test automation

Started by John Larkin in sci.electronics.design7 years ago 50 replies

Can anyone recommend a USB gadget that has an ADC, 8 or so logic port bits, and maybe a DAC? Something easy to program, maybe a serial...

Can anyone recommend a USB gadget that has an ADC, 8 or so logic port bits, and maybe a DAC? Something easy to program, maybe a serial port emulator. 10-12 bits would be good on the analog stuff. The DUT is a photosensor. I need to turn on/off various LEDs in the test rig, and digitize the analog output of the DUT. -- John Larkin Highland Technology, Inc jlarkin at hi...


Frequency Detection Suggestions (corrected)

Started by Bradley Kimbrough in sci.electronics.design4 years ago 4 replies

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a...

Hello All, I am currently building a stabilized Helium Neon laser that uses a 3 mode tube and stabilizes the optical frequency by monitoring a beat frequency between the modes. The beat frequency is 450-600 kHz and is sensed from the waste beam at the back of the laser tube. For a prototype I used an amplified moderately high speed Si detector that fed into a 12 bit 125 MSPS DAC.


Nice MCU for small jobs

Started by Phil Hobbs in sci.electronics.design2 years ago 96 replies

LPC804: 15 MHz Cortex M0+, 32kB flash, 4k RAM, 12-bit 2 us ADC with 1 LSB DNL, 10-bit DAC, the usual serial stuff, 20-TSSOP: 67 cents in...

LPC804: 15 MHz Cortex M0+, 32kB flash, 4k RAM, 12-bit 2 us ADC with 1 LSB DNL, 10-bit DAC, the usual serial stuff, 20-TSSOP: 67 cents in reels, dev board $27. We're using it for a super-quiet diode laser controller where it will run the temperature control and automatic power control loops. I'll never use another ATmega. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principa...


Octal eight-bit DAC for 80 cents

Started by Phil Hobbs in sci.electronics.design3 years ago 10 replies

The Rohm BH226F. If it's any good, it could replace a lot of PWMs. https://www.digikey.com/short/qptnn7 Anybody used...

The Rohm BH226F. If it's any good, it could replace a lot of PWMs. https://www.digikey.com/short/qptnn7 Anybody used them? Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net https://hobbs-eo.com


+- 90 phase shifter revisited

Started by greysky in sci.electronics.design7 years ago 65 replies
DAC

You guys had a lot of great ideas to my original post, but I realized I probably didn't give enough information concerning the application. In...

You guys had a lot of great ideas to my original post, but I realized I probably didn't give enough information concerning the application. In a block diagram, the phase shifter has 2 inputs, one is for the 1MHz sine wave and the other is for a control voltage, probably a ramp generated by a 16 bit DAC. The output is the phase shifted sine wave. The ramp causes the sine wave to be cont...


Frequency synthesis, all-digital type

Started by whit3rd in sci.electronics.design7 years ago 1 reply

In addition to (AD9838 style) things with DAC outputs, there are PLL solutions to the make-me-a-frequency-to-order problem. Basically, start...

In addition to (AD9838 style) things with DAC outputs, there are PLL solutions to the make-me-a-frequency-to-order problem. Basically, start with a reference oscillator (F_ref) and divide it by a counter-based logic (which gets F_ref / N_one), and phase-lock to a voltage-controlled oscillator F_vco, with its own divider F_ref/N_one = F_vco/N_two There are reasons to prefer that both N_o...


Improve PWM outputs with S/H?

Started by whit3rd in sci.electronics.design3 years ago 24 replies

A simple timer can set a pin HIGH for N clock cycles out of 1024, then LOW for 1024 - N clock cycles. That output pin, with some RC filtering,...

A simple timer can set a pin HIGH for N clock cycles out of 1024, then LOW for 1024 - N clock cycles. That output pin, with some RC filtering, generates about the same range and precision of voltages as a 10-bit DAC. But, cheaper. It also has ripple, because the filtered output ramps UP while the pin is high, and DOWN while low, dithering around the intended value, in addition to slowly ...


In The Ever lasting Chain Of Experiments The Next Project, ultrasonics part 7Part 7

Started by Jan Panteltje in sci.electronics.design5 years ago

In The Ever lasting Chain Of Experiments The Next Project, ultrasonic anti-fouling for boats. Part 7 Made a change in the...

In The Ever lasting Chain Of Experiments The Next Project, ultrasonic anti-fouling for boats. Part 7 Made a change in the circuit diagram, changed pin 16 to pin 15 on the PIC: http://panteltje.com/pub/ultrasonic-anti_fouling_circuit_diagram_IMG_5132.JPG this to get the comparator 2 as current sense and on its other input the PIC DAC from its Vref, so you can set the cycle by ...


Signals and Systems for Dummies

Started by John Larkin in sci.electronics.design3 years ago 156 replies

I have the...

I have the book: https://www.amazon.com/Signals-Systems-Dummies-Mark-Wickert/dp/111847581X/ref=sr_1_1?ie=UTF8&qid =1508604326&sr=8-1&keywords=signals+systems+dummies Here's my DDS sim. A tiny ARM cpu generates a DDS sine wave in software, with a 50 KHz interrupt rate and its internal 10 bit DAC. The spice sim uses a sample+hold and quantizer to simulate that. When V4 is around 400 Hz,


"Bogo process"/plant transfer functions for PID testing

Started by bitrex in sci.electronics.design3 years ago 16 replies

I'm looking for a "bogo process" transfer function for a PID loop plant. That is to say something that's not real hardware but just so I can...

I'm looking for a "bogo process" transfer function for a PID loop plant. That is to say something that's not real hardware but just so I can calibrate the software/ensure that the loop is generating sane values prior to connecting it to a real plant and working on tuning. The "bogo loop" would just be say PID core -> PWM output/DAC -> analog filter -> back into uP via ADC -> digital fil


RIS-797, programmable isolated current-source charge-pulser

Started by Winfield Hill in sci.electronics.design9 months ago 1 reply

The RIS-797 project is for an isolated, programmable current-source charge-pulser, using the op-amp MOSFET techniques analyzed in...

The RIS-797 project is for an isolated, programmable current-source charge-pulser, using the op-amp MOSFET techniques analyzed in x-Chapters 4x.26. This uses four 0.5pF isolator channels to run an I2C DAC and the current-source, including a range switch. Total output node capacitance to ground = 5pF, mostly due to DC-DC power-supply module. Two-terminal floating current sources...