I would like to ask a very basic question regarding the input return loss (S11) of any amplifier.

I understand S11 describes how much power is reflected back to port 1 ; therefore , most designers tend to keep the magnitude in dB less than -10 dB (the lower the better) over the desired frequency of operation.

My question is why the return loss drops at certain frequencies before it rises again ? I understand that this might indicate that the amplifier is perfectly matched at those...

Input return loss of Amplifiers]]>

1. When do we choose time domain or frequency domain method to design a control system?

2. I see that bode plot is sufficient in most cases to assess stability, then what is the role of routh hurwitz, nyquist and polar plot?

3. Can root loci be used when multiple parameters are variable (not just gain)?

4. Does...

clarification on key concepts of control theory]]>

I have been trying to plot the DC characteristics for RRAM. I am getting the Transient characteristics correctly but when i do the DC sweep analysis it produces faulty results.

even in the benchmark circuits provided by the RRAM model developers even in the DCC sweep analysis they apply pulse at the input and use .tran command.

Pulse Operation

.OPTION POST

.OPTION RUNLVL=4

.hdl rram_v_1_0_0.va

X1 in 0 rram_v_1_0_0 gap_ini =...

RRAM (Resistive Random Access Memory)]]>

Please, may you advise me if my circuit connection(in attachments) is right or not?

]]>

I need your help to know the theoretical equations of (BW, Noise, gain of transimpedance amplifier type (resistor feedback)).

Also, I need to learn how can I measure BW, Noise, Gain of a Transimpedance Amplifier using ADS(Advance Design System), so that to make comparison between the theoretical values and simulation value of (BW,...).

Please, anyone can guide...

How to measure BW, Noise, Gain of a Transimpedance Amplifier using ADS(Advance Design System)?]]>

I can not see any effect on the simulation results after adding decoupling capacitor. Even when i tune the capacitance value, I can not see any effect. Is this normal?]]>

I have several current limit circuits for several LEDs. In another post on this forum we have been through the voltage, led rating, binning of leds and whatnot. I did build the circuit and it worked flawlessly so I moved on to the final version of the circuit. However stupidly enough I added a diode without testing it. I believe I was reading somewhere and it said you always should have a diode!

So here is the circuit - I have a transistor which pulls the ADJ of the LM317 down to...

LM317 current limit circuit blew up]]>

Breaking no new ground with this one. Another member's thread about a latching off-delay circuit for a relay got me thinking about latching BJT or MOSFET circuits...

I've seen a nice-looking single pushbutton one that only uses an NMOS and a PMOS to latch on and off instantly and I know there are plenty of similar variations on this theme...

Anyway, messing around this afternoon, I came up with this non-contribution to the advancement of humankind:

[ATTACH...

x marks the spot, but where?]]>

If the MCP6001 opamp is set up as a buffer, and receives a triangular wave of peak 0.25V and frequency 1kHz as an input (as in attached green waveform), can it reproduce the waveform at its output?.....or will it not be able to get right down to ground?, as is the case with the LT1006 as attached (LTspice sim and schem)

MCP6001 opamp datasheet

http://ww1.microchip.com/downloads/...1U-2-4-1-MHz-Low-Power-Op-Amp-DS20001733L.pdf]]>

As per Datasheet, To activate AC_OK feature

AC_OK_Pin_Voltage Characteristic

Typ:0.485V

Max:0.518V

For which value i need to design ckt and how accurate it would be?]]>

what is the best power supply design for low noise <100 uv

for analog circuit

LDO ? Opamp based PS ? Else ?

For example application:

Vin 5v

Vout 3v

Noise < 100uv for 0-200Mhz

It will be great also if you can forward me some links to read & learn about this topic

Thanks !]]>

Input signal of 0.2 to 100 mV is from sensor output.

I apply a linear input signal but the output is not linear and its produces noise in the output.]]>

I have to use an NMOS with dimensions (W/L) = (0.42/72). Therefore I stacked up 8 NMOS with dimensions (W/L) = (0.42/9). Now I have another NMOS with dimensions (W/L) = (0.42/74). Please let me know how this can be implemented.]]>

I am using PIC16F microcontroller to get the temperature display on datasheet. Though, I just tested the voltage variation on room temperature only. I am unable to get temperature, because I don't know the right formula for it. I have followed this tutorial...

Right approach to calculate Temperature from voltage and resistor for thermopile sensor TPS434]]>

I am a junior electrical engineer, and I am trying to make sense of a circuit that I have found. This circuit is an RF exciter for a plasma lamp, and it is simply bewildering to me. There are only a few components but I have no idea how this circuit manages to oscillate by itself. I have been reading into Hartley oscillators, Colpitts oscillators, Avalanche transistors, RF amplifier design and yet I am still confused.

Here is what I think I know so far, please correct me...

Trying to understand a "simple" RF circuit design]]>

I wonder is the following connection is the root cause:

Link the "earth GND" to the "power supply GND", the power supply GND is the GND of AC 220V, which has three pins: N , S, and power supply GND.

The contact ESD is +-6KV, ESD3.

Then after ESD test, the AC220V-to-DC5V convert is failure. And the other circuit is good.

Does this connection cause the ESD failure?

Best,

Tony Liu]]>

I have attached a circuit below.

Do you know what would be the closed form expression of vout (t) assuming that C1 is charged to VDD at t=0 and C2 is at 0V at t=0?

The switch turns ON at t=t1

I tried to think about it but I am not able to get a closed form expression after t=t1, as the C1 is charged to VDD (initial value). I feel like this circuit is not linear and doesn't obey superposition because of initial value of C1. What do you think?]]>

I do not understand what does it mean by "One-shot feature" and "turning on MOSFET for one cycle" here what does it mean by powering up MOSFET for one cycle?

I want to turn on ESP8266 by this timer i want to know which MOSFET would be suitable in the circuit

Is there any better alternate approach for same application?]]>

I doing 555 astable simulations in LT spice and I got the output. my problem is expected Ton and Toff time is not matching with my simulation results.

Below is my schematic.

The formula I used to calculate Ton and Toff times are given below with results:

Ton=0.693(R1+R2 x C)=5.04Sec

Toff=0.693(R4 x C)=10.06

Simulation results:

Ton = 5.96Sec

Toff = 11.88 sec

I am...

LTspice 555 timer duty cycle calculation help]]>