I have specifically 20x LM317 constant current circuits which drive LEDs and I would like to turn them on and off using a microcontroller.

Would you put some mosfet before the LM317 to shut it down? or perhaps after? Or would you do it differently?

If so how do I choose a mosfet which can take 30v @ 600mA ?

Perhaps you are aware of another IC which can give constant current but with Enable pin?

Thanks]]>

I selected ADXL356 as an Accelerometers.

But I don't know two things:

1. Velocity effective value resolution should be 0.01 m/s, does ADXL356 meet the requirement?

2.Displacement peak peak resolution：0.01 um, does ADXL356 meet the requirement?

Best,

Tony Liu]]>

As the title implies I have a 24v (500mA) DC motor for a vacuum pump and a power supply of 30v. I do not need an H Bridge or complex drivers, I only need to turn it on or off using a microcontroller and preferably without relays. How would you go about it?

What I was thinking of is using a TL2575 ADJ which is a switching regulator that can take my 30v down to 24v and also have the enable pin which can...

Driving 24v Vacuum Pump - DC Motor]]>

Because we are comparing DC voltage to DC voltage in the proccess shown Bellow.

Thae comperator (which is implemented as OPAMP) has GND connected to it.All the calculations we assume a virtual ground.

But there is a contadiction because if we compare DC voltages then we have BIAS voltages on the input of the OPAMP.

a virtual ground exists if we have AC signal which is not the case in SAR ADC.

Where did i go...

SAR ADC converter analog problem]]>

Ignore the pictures inside README because they do not reflect the current circuit.

Without using external capacitor, could anyone advise how to solve this issue of LDO load transient response in the event of a sudden load change ?

I'm a beginner for analog circuit design, and I'm reading a following book written by Prof. Sedra.

https://www.amazon.com/Microelectronic-Circuits-Electrical-Computer-Engineering/dp/0195323033

Ideal voltage amplifier model has an infinite value of input resistance (Rin) and a zero output resistance(Rout).

I understood that entire input voltage should be dropped across Rin, and its output voltage needs to be dropped to a load resistance...

voltage gain and I/O resistance for ideal amplifier]]>

I would like to use a digi pot to adjust the filter sweep position but wonder if the THD of the resistor is a factor?

I will be using the resistor (digipot ) as a shunt between the balanced lines on an audio input of a preamp.

I can see if you pass the signal directly through a resistor it would introduce noise, but how about in RC filter configuration ?

I would place 2 x capacitor in...

RC HPF filter noise?]]>

While doing electrostatic discharge (ESD) testing, it seems that noise is coupling into the MR pin

of the TPS3823 causing my microcontroller to be reset. I took a 0.22 uF capacitor and soldered this between pins 3 (MR) and 2 (GND) and now I am

Here is a screen shot of the circuit:

I was wondering if there is a better value to use for the capacitor...

ESD on SUPERVISOR POWER IC]]>

Suppose we have a Fractional-N frequency synthesizer employing an MMD + 3rd order MASH loop. If we want to divide by the fractional value 100.XX ( where XX = fractional value ) , the MASH will instruct the MMD to divide by values between 97 - 104.

My question is , which is the maximum delay for a new division value to be loaded from MASH to the divider?

At first glance, you would say it should be 1 period of VCO frequenct in order not to lose a single period between the 2...

MMD division value load maximum delay]]>

I want to simulate the phase noise of a multi modulus divider at the feedback path of a fractional frequency synthesizer.

The input frequency of the divider , which is the output of VCO, is 16G. The divider then divides this value with an average ratio of 200, which is controlled by a MASH. So the division ratio is changed between 197 and 204 , depending on the output value of MASH.

My question is how can i simulate that phase noise? Which is the correct analysis?

Best...

Multi modulus divider Phase Noise simulation]]>

I was not able to get the pole frequency from DCop values of a simple circuit. I need to use the DCop values in order to verify my calculations used to govern my design process. This is also kind of required, or at least much welcomed in my thesis. Also knowing from where the performance limitation are coming from, has a huge value. With this question I ask you to help me figure out where is the source of this discrepancy. This question is basically equivalent to "How to...

Discrepancy btw pole frequency calculated from DCop values and AC simulation results]]>

But Iout_max of LDO is proportional to width of output mosfet (M20) , Rds of M20 is inversely proportional to width of M20.

Given that output impedance is a parallel impedance configuration between Rds of M20 and (R1+R2), so Iout_max is proportional to output impedance of LDO.

If I need Iout_max = 3A, then my PSRR result looks very very bad.

Trade-off between LDO max Iout AND PSRR]]>

I know that the magnet is there to "bias" the choke somehow.]]>

I am trying to design a dual-band Class E power amplifier at 2.4/3.5 GHz using only transmission lines for input matching and output matching networks. In the first step, I designed and simulated the circuit on ADS schematic using microstrip lines as in Figure 1

I extracted the results, the performance at both frequency bands was as expected (about 5.3 W and over 70% PAE).

After that, I had created layout look-like components for...

Huge difference between results from schematic simulation and momentum co-simulation]]>

In the attached EMG amp design the output stage allows for an offset and gain adjustment( for calibration) however there is an interaction between the two adjustments which ultimately prevents the desired output gain. The circuit design includes a preamp stage, 60hz notch filter, RMS to dc converter, and the final amplifier with gain and offset adjustments.

The theory of operation is the inject a 200hz signal (at C61) at two reference levels then adjust the output to to obtain...

Offset / Gain interaction]]>

I'm trying to calculate a feedback compensator for SG3525 IC. I need pwm ramp voltage for this IC but it's not given in datasheet. How can I find or calculate it?

Thank you.]]>

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how do i calculate from the the standart deviation of the whole device(DNL INL)?

I have found a similar manual for the ressistor mismatch in flash ADC as shown bellow.

But in general i am having problem connecting comparator mismatch with total output mismatch (DNL INL)

Thanks.

]]>