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236 Threads found on Voltage Controlled Current
I have designed a ring vco with the input voltage ranging from 0.7 to 1.8V, but i need it to work below threshold voltage too. The increase in frequency with respect to the voltage has to be linear.135293 Regards, Vidj
Poorly controlled peak current? FB pin simply not designed to provide an exact current limiting. I have used a voltage clamp for FB in an application of a current mode controller with similar internal circuit and it did at least "work". Getting specifications for tolerances etc. of this unsupported function (...)
You need to be more specific about the application. What do you mean by impedance and impedance to what and what are the voltage and currents in question? Are you talking about a controllable termination in a high speed bus, variable resistance for voltage controlled gain, or a variable high power load? Any of those (...)
Even if both currents would be exactly equal, the circuit doesn't generate a "voltage window" rather than a voltage difference V1-V2 with unknown & floating absolute voltage somewhere between 0 and 5 V. I'm not aware of ready made controllable current source ICs in the ?A range. I designed similar (...)
Hi, all amplifiers I am aware of, "modulate" the power supply voltage/current at their output. The amount of "modulation" is controlled by the lower level signal at their input (base for a bjt, gate for a fet etc). In other words, the original signal waveform is not touched at all. It just drives the transistor, so that it can modulate the (...)
You could use "Step-Up voltage Regulator Module" like LM2577 with below circuit: 133170 For your application you need to change several thing: 1-Remove 7805, C11 and C12 . 2-Replace Zener diodes by 1N4746A (18V,1W); If circuit current consumption is higher than 100mA ,you should increase the maximum Power Dissipation of dio
Think of the BJT only as a Ibe current controlled Rce resistance much lower than the input bias R. Vce may start with a saturation voltage, Vs between 20 and 200mV depending design of transistor then Vce rises with pullup current Ic*Rce in a linear fashion. Rce is the differential collector emitter resistance that is (...)
Hi All I have a current controlled dc/dc full bridge converter with complementary output +85V and -85V that feeds audios amplifier. I'm trying to find the best way of measuring the full bridge output voltage (+85V/-85V) to provide the proper below 2.5V level signal for voltage loop of full bridge. The differential output (...)
You need to learn about the current-controlled transconductance amplifier to understand how the voltage-controlled lowpass filter works. Many years ago the CA3080 was the first current-controlled transconductance amplifier, then later came the LM13600, then the LM13700. Look them up in (...)
Hello, I need small help regarding the floating gate device. I am designing a non-volatile memory cell and foundry does not have model for floating gate . So I used the voltage controlled current source to mimic floating gate. For output characteristics, I already had the measurement of previous fabricated custom made floating gate and I (...)
current scaling is only a matter of FET and shunt selection. FETs with large Cgs and Cds might require some compensation and load capacitance isolation with fast OPs, but should work in any case. For higher supply voltage, I would use two OPs with individual supply voltages, the I/V level shifter can bridge even higher supply levels like (...)
Thanks Brad For example I need 40 dB gain for my amplifier design means Is there any relation to the current vs gain. Because if it has any relation then I choose the current from that relation to achieve my gain spec. The transistor is a voltage controlled device and the gain depends on the transconductan
I was reading a paper "A Novel Simple current-mode Multiplier/Divider Employing Only Single Multiple-Output current controlled CTTA" regarding analog multipliers. And in the introduction part they have mentioned abt BJT. "Unfortunately, they are suitable for working only in voltage-mode. They cannot be applied to employ (...)
No, my circuit is constant voltage, not constant current. The input is listed as RMS so it might be a sinewave. The series resistor and input voltage establish the current. A Slight re-arrangement makes it a voltage controlled low side current
Hi All, I have a current source (in 65nm CMOS technology) which pulls down the output from a logic tree and is controlled by a voltage (EN). I want to change it so that I now have this control using current instead of voltage. So essentially, I want it to be current (...)
When Vgs is > Vth it means above the threshold of saturation and must have a supply of current available between Vds so thus Vds is not zero and the voltage drop is the standard spec characteristic of RdsOn. When Vgs = max i.e. >> Vth then it is fully saturated and reached the maximum conductance or best case low RdsOn. In between these level
i think its because A FET is voltage controlled device because its output characteristics are determined by the Field which depends on voltage applied. - - - Updated - - - FET is voltage controlled current source
Tl431 Pin 3 is connected to Shunt resistor RS via R17. Can i expect voltage greater than 2.5 across shunt resistor?
Hi, I have a question about the voltage amplification stage of an (audio) amplifier. I just took this attached schematic as an example. The VAS transistor Q4 is driven by the output current from the input pair. It is said the VAS (voltage Amplification Stage) is a transimpedance stage, converting a current input into a (...)
If you have a transformerless inverter with PWM control, then the current must be controlled to match the (filtered ) voltage with no phase error, such that the net power dissipation in your inverter is never exceeded. Do you have this control? Do you have ; Suitable margins for component specs. with a design spec? thermal sensi
Hi all. I am currently working on a project which involves an mp3 module and i would like to get an led to react (in light intensity level) to the amplitude of the signal it generates. i am using a transistor to drive the led with the base connected to one of the mp3 modules speaker outputs which is amplified(enough to power a 5w speaker).the emitt
How to control the Magnetizing current..?? I have an toroidal transformer with ratio of 1:10 for 40 amp secondary at 15v. The transformer primary Resistance is in miliohms. I am trying to switching the transformer with triacs but the triac of 15 amp rating does not handling the Magnetising current at start up. Can anyone having solution
im using a xssr-da3805p solid state relay which is connected to a uc. whenever the input voltage is 0/low, there is still a reading. btw, my load is an 3watts Led buld controlled by a PIC18F4550. Thanks!
Hi I am studying HSPICE. I want to reuse the result as an input variable like controlled source(current controlled voltage source). For example, if assume the current I1 flows through resistance R1, I want to use the I1^2 in the current controlled (...)
If you have a DC supply for a motor being controlled by a SCR or thyristor then switching the device off would have no effect until the current through it falls to a low value (Ihold). This would occur naturally if the DC supply was unfiltered since the voltage would fall to zero between every half cycle. If you connected a second device (...)
I was thinking something like this for adding the modulation current: 113699 Will the switch cause spikes in the pulses? What voltage controlled current source do you propose? Does some one has simulation model for laser diode? plz help
I suppose you want to simulate this in a true application, meaning the inputs are controlled by a generator with known output impedance? In this case connect the inputs with noiseless resistors to the required bias voltage. Or subtract the resistors noise, if you can't find noiseless resistors in your libs.
THis is a broadband Op amplifier controlled by C ratio with DC blocking breakpoint at R19//C20 on feedback. Since the diode is anode grounded with reverse biased PD the cathode is at V+ with null current and drops input voltage , inverts to a positive peak AC amplifier with detected light.
Without specs or details on implementation, I assume Relay provides for slow adjustments with tap change and lifetime limit on current load switches is unknown. This is common for some high power (MVA) distribution or feeder transformers to have active load switch taps with relay control. Servo implies stepper motor controlled variac which als
Hi all, I just start to learn verilog-a and want to create a voltage-controlled current source(vccs) in cadence virtuoso. I learned that cadence would check my syntax automatically and create the symbol if the code is OK. However, when I open a new cellview in verilog-a, I can't save the code, so I can't convert the code to symbol... (...)
mainly two types of control one is scalar control and other one is vector control see the basic formula N = 120f/p N in rpm F >> supply frequency p >> no of poles. u can vary the speed of induction motor by varying frequency. but in order to work with constant torque application. T $ phi * I Phi >> flux Phi = E/F (derived from trnsfmr
The control topology makes no sense. You can either operate the system with current or voltage controlled feedback. But what's the purpose of substracting voltage and a current proportional value?
Left circuit is well known Widlar current mirror.. Right circuit is a voltage controlled current mirror/source..
If you have no load, where is your 100uA going? It sounds like you have a voltage output, and what you want is a current output. So, what you want is a voltage-controlled current source. This might help:
Hi, In a textbook the emitter follower is depicted as a voltage series negative feedback amplifier and a current series negative feedback amplifier as well. Difference between the two circuits shown is only that the one, which is a current series feedback amplifier uses another load resistor coupled to the emitter resistor using one (...)
You should read some basics before asking questions. Knowing nothing you mAy be confused. When the junction transistor was invented, the main collector current was controlled by the base current. Before transistors people used vacuum tubes to control the current by an input(grid) voltage. Therefore (...)
The relay contact at transformer secondary side seems does not make sense, due it is controlled by transistor output, which interrupts its biasing current. Except it, seems to be a primitive control for over voltage, interrupting the power leading at output just under a certain limit defined by potentiometer. By the way, the secondary (...)
I'd think VPP & VNN are controlled by the same DC voltage (which is correct), but also by the same ac voltage (in phase), so there's no ac differential input at all.
Hi there, I'm working on buck converter. I have got confused for differences between open loop and closed loop buck converter. I designed open loop converter.I have been considering a lot of parameters and trades of between them, such as output voltage ripple, inductor current ripple, switching frequency, load current,and like them. I have (...)
Unipolar or bipolar current? Output voltage range? 1k*100mA would already require 100 V. - - - Updated - - - What is your load capacitance? This could be your problem. Can you measure it? I presume, load capacitance is just given. For the current source design, the allowed maximum (additional
A pot is a voltage level control because you place it in a voltage divider with the 5V supply. Are you trying to control is from a 0-5VDC microcontroller? I guess I don't understand the question.
Batteries have a very low effective series resistance (ESR) which rises with low charge levels and end of life sharply. PV panels have high impedance like current sources but not constant. Often maximum power transfer is around %75 of Vmax. The voltage will be controlled by the part with the lowest impedance, but OHm`s Law can be (...)
Since the intensity of a LED is controlled by current and not voltage, the best way to dim it is to use PWM and a variable duty cycle. You set the max current by the output voltage and a resistor to generate the current through the LED, or you can use a special switch mode driver that (...)
Can anyone suggest me some good circuits working at 90nm for- 1) current controlled voltage Sources (CCVS) 2) voltage controlled current Sources (VCCS) 3) current controlled current Sources (CCCS)
Hi I am trying to switch current in load using low side switching through controlled voltage into hi precision resistor in series with the load 1st I used a pnp transistor "FMMT593" for switching the problem was hi rise and fall time at low current of 50uA snap shoot is shown in attachment aaaaaa10.bmp Then I used a (...)
Vdd 2 0 DC 5 GND 1 0 DC 0 You probably start with learning SPICE syntax. Component type is identified by the first letter: Vdd is a independent voltage source (O.K.). GND is a controlled current source without transconductance specification.
Aim: :!: I want to design a voltage controlled current source based on Look up table in ADS 2012. I searched and I could not find anything useful. Problem: I used DC simulation on a diode to get I-V curve. Now I want to make a current source generator based on the simulated values. :?: What should i do?
Hello, I would like to know how is the relation between the voltage and the current in a voltage controlled current source. In my case I have a gain of 1 does that means that for 1 Volt I will have 1 Amper? If not which is the relation between the two of them? Regards
I need to study for a test and one of the criteria will be similar to this rectifier; 98970 Given: RMS voltage, L, R and back EMF, alpha with continous load current. To determine; -Output voltage and current. -Second and fourth harmonics and Output RMS current. -Power delivered to the Load. (...)
Apart from the question if the connection of MOSFET switches is reasonable or not, to allow a swing below ground, the gate voltage can be controlled by PNP in common emitter circuit, you'll probably need another NPN as level converter to drive the PNP base. I would usually expect a source-to-source tied pair of antiserial FETs with common gate c