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267 Threads found on Bipolar Current Current
Full bridge switcher is the usual topology for bipolar peltier supply, it's usually simpler to design it for symmetrical current although dick_freebird is of course right that heating current demand can be expected much lower than cooling current. I have implemented a (...)
I have a lateral bipolar design. how do I plot the graph for Ft, Fmax Vs collector current density (Jc)? the tool I am using is sentuarus TCAD. please help me with the script for this plot....
Hi, I am using dspic30f5011 controller and I can generate PWM wave by using output capture compare module.Now,I want to control the 4-wire bipolar stepper motor with PWM i.e, rotation speed.So,what driver I have to use? Thanks and Regards, M SAI KIRAN.
Your schematic appears to be a flyback. current flow in the secondary is normally in one direction. This means the output stage is designed differently than the conventional tapped secondary bipolar supply. Example, this arrangement:
I presume standard 5V transceivers, although specified only for 4.75 to 5.25 voltage range will work well at 4.5 V. Cheapest are bipolar devices like SN75176, but they have uncomfortable high quiescent current. My standard general purpose transceiver is CMOS SN75LBC176.
A buck-boost inverts supply polarity. Output is referenced to ground. That will give you -12V. You can use an ordinary buck converter to get +12V. Then you'll have bipolar +-12V, both referenced to common 0V ground.
The input current of an opamp that has bipolar transistors on its inputs is very low. They are made so that the input bias current does not change with voltage or temperature changes. An opamp with Jfet or Mosfet inputs has NO bias current, instead it is extremely low (...)
Do you have a 150V supply to generate the pulse from or are you asking the whole thing to run from 5V? If you have a high voltage supply already, all you need is a suitable bipolar transistor or MOSFET and a load resistor. If you need to generate te high voltage from 5V, please tell us how much current you need to provide to your load and (...)
An ordinary bipolar transistor needs a base current of 1/10th the collector current for it to saturate well and not get hot.
BLDC's often use dual full bridges like a DPDT switch which reverses polarity of single supply or applies zero current with both at V+ or both at 0V. Usually each bipolar or "Double Throw" switch or " half-bridge" is a MOSFET pair. A full bridge switches both ends of the coil. There are tons of BLDC web links.
It can sink more than source. 10 vs 3mA Hence "Minimum pull-up resistor of 500 Ω, from VCC to VIOUT | "RL VIOUT to GND 4.7 kΩ" (min) typical bipolar (BJT) specs are asymmetric.
Your schematic does not show Mosfets that have drain, source and gate pins. instead it shows ordinary bipolar transistors that have collector, emitter and base pins.
This depends on a few things. For bipolar mirrors, you'd need base current buffering to keep any decent fidelity (figure each dependent "steals" 1-2% of pilot current, as does the primary). Then buffering puts you down to sub-%-per-stage. Beyond that you probably need more gain and replica feedback to get (...)
Theoretically they don't have reverse recovery (no minority charge carriers), practically they have non-linear junction capacitance which causes a current waveform that isn't very different from a bipolar junction diode. See also this previous thread
L298 is old bipolar technology with limited efficiency. In so far it surely won't stay cool. There may be a problem of irregular (too fast) switching, you should check the waveforms with an oscilloscope. In most SM applications that require hold current, the current can be reduced. This is possible by (...)
MG150Q2YS40 specifications are based on a bipolar +/- 15V gate drive with 5.6 ohm gate resistor, considerable different from what you have planned. It's however a 150 A IGBT module and good for several 10 kW, a bit oversized for a 4 kW inverter.
I would think load dump suppression devices should be satisfied with a bipolar TVS and conducted noise improved with low ESR C on input or series choke. A LISN (50Ω/5?H) is used for AC power line conducted emissions measuring voltage for AC line external connections. Battery conducted emissions , can be done with a current (...)
Without getting into too much detail , understand that your Tx is bipolar signals but this chip uses an Rx threshold of +1.6 +/- 0.8 with hysteresis , approximately and can only supply 2mA if the RS-232 load is zero. The source and load impedances of RS-232 are designed often with 1k source and 10k loads. So 2mA load will cause transient dips in
You are looking for resistance rather than "impedance". Rb has been used with classical bipolar OPs to cancel the addional offset caused by input bias current. As already mentioned "input balancing" could mean a lot of different things, I won't use the term here. Rb = Ri||Rf is the right value. In case, I would talk about source resistance (...)
It all depends on the ESR and load current requirements. 555 can drive so many hundred mA with mV drop which implies the ESR of the driver. typically 10 Ohms and is related to power handling capability of drivers or RdsOn or Rce of bipolar drivers. YOu can get as low as 1mOhm ESR on high current half (...)
Saturation (or the lack) - to get tolerable Vce on a bipolar you have to load up the base with charge (current) and this then has to be turned around, but has a long storage time. bipolars are real fast to turn on. It's turning off that's slow.
I suggest a simple solution... Use a MOS transistor instead of a bipolar for switching applications.MOS transistors have much less Rds resistance and drop-out voltage across D-S is much less than bipolars.
I would use MOSFETs rather than bipolar transistors. Much less power dissipation.
Try to refine your specification: - frequency range - unipolar or bipolar output - current source compliance (output impedance, voltage range)
The circuit is usually called a bipolar current source. But you missed to tell about the problems you experience. The circuit has correct feedback polarity and should basically work. For a practical design, there are several point to consider like amplifier common mode range and stability requirements. It should be also noted that the (...)
bipolar output amplifiers come in a wide range of products from 0.5mA to 5A and wide range of slew rates. So your assumption depends on application.
Lp will be around 1mH Turns ratio such as 2:1 depends on primary voltage if much higher than Vg and has the advantage of boosting current. You will need magnet wire and tape insulation to withstand a surge of 3kV or 2.5kVdc L*dI = V*dt must be well under the core saturation limits. bipolar drive gives twice the (...)
First decision: read bipolar AC current signal and process it in software (needs input bias to Vref/2) or implement a precision rectifier circuit in front of the ADC and process a DC signal. You'll find examples for both approaches in previous Edaboard threads, did you already notice the suggested "similar threads" at the bottom of this page?
Vcasc is not independent and it has to be lower by at least Vce(sat) from VDD to prevent the bipolar transistor to entry into saturation.Also Vcasc defines also Vds of diff pair and Ve of bipolar pair.You should find a so proper Vcasc that satisfy those constraints.Increasing or decreasing Vcasc will not practically change the tail (...)
There are millions of different active switches with constraints for DC, BW, current or Rs, single-side hi/lo and bir-directional. Here are ON-Semi's patented MOS bidirectional switch used in IC's and also for ADSL 110571 Same is done with NPN & PNP with bipolar base/gate drive . If CM , common mode isolation is required
A variety of effects occur in bipolar transistors, which are not included in the ideal transistor model. These include the base-width modulation effects and the current due to recombination in the depletion layers. High injection effects, base spreading resistance and emitter current crowding. As for a (...)
Hello all, I'm new to these forums, so I assume that this would be the most relevant area to post a question. I'm working on creating a schematic for a mixed signal IC. I'm stuck with understanding the interface between a MOS current mirror and a bipolar output switching circuit. The circuit diagram I have made does not work from the (...)
In a practical sense, if both time constants, T1, T2 are greater than the triangle ramp period, then the ripple may be straightforward. V=I*ESR , where ESR = R1//R2. The voltage ripple is regardless of value of capacitor. With source current suggested as bipolar triangular , this results in triangular voltage ripple.
The only problem is the Op Amp used requires a bipolar supply because the input does not operate near the supply rail. This device also has high slew rate dv/dt to switch the MOSFETs fast. The 10 MOhm feedback to (+) creates positive feedback or hysteresis for full speed turn on to drive the capacitive gate during transition. This puts the swit
No. A bipolar transistor doesn't conduct current in both directions.
I`m making bipolar power supply using transformer without mid point. Because of that I`m using single diode. I need larger on the output because the supplied schematic drains current on pulses and I need big buffer. I`ll fix this somehow, but I have another problem. I`m draining about 40mA. In spite of the smaller cap on
Be sure to read all the FAQ's The output stage is designed for use with a bipolar power supply and diodes must be inserted in series with the output , to allow a minimum output bias voltage without creating a measurement offset.
Hi guys, About the transistor, i thought the electron must flow from negative power supply --> emitter --> base --> positive terminal . 104045 But why it also can flow from negative power supply --> emitter --> base --> negative terminal . 104046 I refer from this link: w
ground is arbitrary. So you can define it either way. A split 3V rail with a buffered midpoint or a bipolar 1.5V dual supply.
hey guys, the requirement is to construct a two constant current stimulators delivering a max of 1.3mA (P-P) bipolar square pulses through a 2kohm load. the two current sources are to be isolated from each other, additionally to enable independent control of the two (...)
hey guys, the requirement is to design a dual constant current stimulator (1mA through 3kohm max. load), which are isolated from each other. the right side of the attachment shows the output required from this circuit. its a bipolar square wave at 2Hz with 50% duty cycle. the following description is for a system i think might work but (...)
This is normal behavior of a bipolar junction transistor. It is also present in any PN junction. When you supply more current then you need to almost saturate the transistor, some of the current is stored in the form of base charge. During your negative half of the pulse, this charge has to be removed (...)
Most people are confused with "saturated" and "active" regions for a Mosfet because they are the opposite to a bipolar transistor. Power= the voltage across it times the current flowing in it. When a Mosfet is fully turned on it has high current but almost no voltage then its power dissipation is very low. (...)
Hello all! I found a bipolar power supply circuit and used it for a while successfully. I got +15 (V) and -15 (V). But now I get +15 (V) and -22 (V). Input voltage sof the voltage regulators are +35 (V) and -35 (V). In addition, when measuring the voltage at the point indicated by the arrow I get 75 VAC (!!!). Is this normal for such a circuit?
I'm starting a curve tracer design and the 1st fundemental circuit I need to test is a bi-polar current source I can control digitally as the project is micro-controller based. After looking at all kind of different solutions I've found the good old Howland current pump in an application sheet. Using the DAC (by ADI) or some (...)
Hello guys, I have a bipolar two phase 1Ampere Stepper motor along with a driver IC. My application requires the motor to drive a load with its max power. The IC functions well but its limitation is that it would get burned if motor draws more than 0.3A per coil. KIndly suggest me what should I build to support the function of this IC without any
Matching depends on assumptions like temperature being equal - a bad bet in a pair of power devices if collector voltage or current aren't similar. Like the reason you don't parallel bipolar power devices, even identical ones, without adequate ballasting. I think this concern is why you don't see much of this kind of product, in the (...)
no you cannot , these have built in bipolar transistors in Hbridge configuration to drive the 2 coils of Bi-polar stepper motor . what you really need is a "allegro" A4989 this have all the "hardware" needed for microstepping and gate driving circuitry , So you can connect your outside mosfets directly to this IC . the control is via SPI as i rem
The actual current output of a simple two-transistor bipolar current mirror changes with the voltage at the output terminal. I'm trying to reduce this without using a higher part count mirror (no Wilson, Widlar, etc). I've tried with the transistors on hand, the 2222/2907 and 3904/3906. The latter (...)
To obtain your negative supplies, it is feasible to use buck-boost converters. Or, consider using an H-bridge and transformer (center tap) to produce your bipolar supplies. Can't say whether it will reduce your parts count and labor.