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1000 Threads found on edaboard.com: Transistor Protection Circuit
What sought of protection u want to go for, current limit, over voltage for PDD, For current limit u can simply build ur circuit around two PNP transistor. For overvoltage detection also u can go for simple opamp with a zener voltage reference . But decide wat protection u want to go for
Hi Shai, If in an regulator if the load ouput point has accidently been shorted to ground then a large amout of current will flow through the circuit and this can damage the pass transistor. Hence a short circuit protection can be used to detect this. Over current in a regulator can arise if the output load falls to a (...)
Hi gays: I have a question about LDO over current protection. the question is following: When the current of output transistor is to high, the protection transistor (PMOS) will pull up the gate of the power transistor to high voltage and close the power transistor. but the current flows (...)
What?s the idea behind the actual circuit? Load disconnect if input voltage lower than some fixed level? In this case I think you need to wire zener diode in series with the input of transistor?
105250 Hi,I am laying out an OPAMP in cadence IC 615using AMI 16 tech and would like to implement a thermal protection circuit that will shut off the power to the transistor if the temperature rises above a preset value. Could anyone point me in the right direction?
In case of using X9572XL to receive digital (TTL and CMOS) input directly from connector. Any recommendation for input protection circuit that will prevent CPLD pin to destroy from uncertain condition. THX
Hello, Could you provide me a schematic or needed devices for a Li-Ion accumulator protection circuit? Thank you in advance, Cube007
Hi Experts!!! Please give me a advice or other solution for below circuits. It's a over temperature protection circuits. Thanks!!!
hi, all: now i am designing (obverse design) a VFM step-up dc-dc converter with 3.3V output and must protect the power switch. can you provide me a LX switch protection circuit or VLX limiter? thanks in advance. kind regards, wonbef 2005/06/03
Deat All, Can anyone give me any comment about the short-circuit detection and protection circuit used in PowerMOS? My operated current is 50mA for normal and 250mA for short-circuit . Thanks a lot.
besides adding those ESD protection circuits. For those transistors which directly connected to IO pad, you better use drain extended transistors.
Hi folks, Can anyone here recommend any paper or book on ESD protection circuit? Regards, Wind
Please, Give me detail circuit diagram and theroy about "UNDER AND OVER protection circuit FOR AC & DC VOLTAGES". Thanks, S. Kendre
I want to put a speaker protection circuit at the output of audio amplifier (LM386). I am using 8ohm, 0.5W speaker. The voltage swing at theinput is 12V. I plan to increase the gain of audio amp until 200. Please suggest simple circuits. Regards, Imman
I need to design ESD pretection for my circuit, but I don't have any idea about that. Could anyone give me some hints on ESD protection circuit design?:|
Are there test bench available (for example, with Human boday model, 2KV)with which the ESD protection circuit can be simulated?
I currently have to design a analogue input circuit that measures 0-10v for an industrial envronment. The 0-10V will be buffered (op-amp) and then low pass filtered (RC) then used as a input to a ADC. What circuits do people use to protect their inputs from over voltage, voltage spikes, shorts ...etc? I mean apart from current limiting resi
Hi guys, Im new to this forum...need some help on my project. I need to build a protection circuit for my PSU so it wont fried the circuitry...fuse on wall plug is not an option. Anyone can help? Thanks!
Hi guys: in recent days, I looking for the papers about the over current protection circuit of the LDO, but I only find one paper in IEEE and the circuit can't work over all corners, can some one recommend some papers to me. and give some opinions about over current protection circuits. thaks a lot!
Could someone give me some advices for how to design a overcurrent(or short circuit) protection circuit for power amplifier IC's output stage. I use the pseudo source follower output stage. Reference: "A High-Performance CMOS Power Amplifier" John A. Fisher "Class-AB High-swing CMOS Power Amplifier" F.Mistlberger and (...)
how to design the undervoltage protection circuit for SMPS?
yes, I can afford 1k Ohm resistor, then how to protect the Op Amp? As this is a MOS Op Amp, the parasitic reverse diodes of the output transistors of your Op Amp should stand the ≈15mA ((16V - Vf(diode)) / 1kOhm) - depending on the w/l ratio of the output transistors of your Op Amp. (If you can afford a series res
I need to know how to design a Surge protection circuit. Can anybody help on this?
This is a simple overload protection circuit in a power supply. Usually that configuration(the differential opamp and diode) is use to control the power supply whether function in current mode or voltage mode(refer to 2nd attachment). However, i modified it become an overload protection circuit(the part that i drawn in the (...)
Hey i want to simulate undervoltage protection circuit in orcad. How can i design the circuit so that load voltage decreases to say half its original value after 5m seconds?
Hi, I'm looking for building a custom protection circuit for rechargeable lithium ion polymer batteries. The three protection offered by the standard PCM are : - overcharge voltage - over discharge current - cut-off voltage Assuming, the charge voltage is regulated and controlled by the charger IC, the over discharge current is (...)
Hi, I am measuring current across a resistor by connecting an electrometer across it.i want to make a overvoltage protection circuit for the electrometer that as the voltage across the resistor increases say 5 volts protection circuit supress the overvoltage and not direct the overvoltage to the electrometer. Kindly give (...)
Dear all, For the battery protection circuit, i found this schematic diagram. How do i construct this circuit...and what is Eb+ and Eb-??? appreciate the help
Hi, We are facing problem to make our board get passed in the EFT testing. The same circuit is used in many PCBs which passed the test standard. But, in the present board, we couldn't. For the protection we used only one bipolar TVS diode and there is no ferrite bead or resistor in that path. Please help me by providing few design tips, equati
Hi All, Can any one help me what architecture of CMOS over current protection circuit suits for NMOS driver. Bye.
Hi, I am designing a circuit, in which the signal level rises to the maximum of 24V, but there is a potential that somebody can wire 230VAC to the input supply instead of 24V. I need to design a protection circuit that uses SMD parts to create the protection from 230VAC. The circuit I designed (...)
I am making a audio current limit protection circuit.and I got a block which share me some ideas. you can find the block. 79802 they recommend to use LT6100 for current sensor,I use LTspice to simulate the result and find it is useful to DC but not good for audio signal. the output is also a sine wave and the amplitude i
Hello.can anyone tell me which diode is the best choice for reverse polarity protection(12v DC)?Can you mention its voltage¤t spec?
please suggest some reference designs of protection circuit that receives digital input??
please help me designing a protection circuit in which surge protection as wel as mosfet based reverse polarity protection is included...the maximum current that the device can handle is 2 ampere and the voltage that it can handle is accorsingly please specify the fuse specifications and zener diode specifications..how to (...)
hi guys, could you give me some advise about how to design a effective protection circuit as mentioned and the cicuit should consist of the simple componets only, cause the boss do not wanna spend too much money on it!! :cry: .i have tried some devices like zener diode or power TVS,but they can not solved my problem completely,and the 120v
I have given a 10 v ac for adc circuit by using voltage divider circuit.after that i have to give this voltage as a input to adc.inbetween that i have to include protection circuit which is used to protect my adc from over voltage.for that i have used schottkey question is the input of the diode is ac the diodes required a (...)
I am making an over charging protection circuit for a 12V, 30Amps battery. I am confused that when charger will be removed, will the battery voltage remain at same potential as the potential with charger? E.g when charger is connected voltage measured is 14.2V, when the charger will be removed, battery voltage will be 14.2 or less than 14.2?
You would be better off, I suspect, using a MOSFET as a switch as the voltage drop across a transistor would drop the voltage below GPS voltage requirement. I am sure you can find many MOSFET switch circuits on the internet.
Hello Everyone, I have a spec given as, there is a output voltage of 12V from an external connector. This 12V should be used to power our circuit board (Our circuit needs 12V). But before connecting we should have input protection circuit in our circuit board because from the external connector there could (...)
It?s a fairly simple scheme the current limiter. Think of the current-limiting circuit as a resistor that can change its resistance. It will automatically detect the amount of current that should be flowing through and change its resistance accordingly. The incoming current first goes through a current sensor (R1) whose output signal goes to a PNP
You show a DC input of 16V but also a 10V capacitor over the same point? What are the voltage and current range you want this to work? The circuit will have very bad regulation as there is no proper feedback to compensate. At the moment, the output is only dependent upon the gain of the two transistors. That will change with temperature.
which tools can i use easy to draw transistor level circuit schematic and can output spice netlist for hspice simulation in linux enviroment? i hope the tools can be easy get, free or cr*ck already.thanks Hi A. Oregano (Free for d/l) 1. Xcircuit (Free for d/l) 2. h**p://bach.ece.
I need of a simple circuit for protect integrated circuits 74HC245 ( that i use like buffer to interface PC with test circuits ) from unforeseen event strong absorptions of current. Thank you in advance
The block may be used for thermal and star-up circuit for bandgap. It protects the power transistor(pass transistor). The circuit may be a LDO. There are bandgap, protection circuit and star-up ciruit blocks.
attached is a figure of normal esd circuit. we have three diodes: Zenner diode and diode to PWR will protect circuit when power pin is floating. However, what about when esd happens, the ground pin is also floating, what is the discharge path? to substrate?
The need for extra protection really depends on the process. Some of the processes I work with have very fragle NMOS transistors (drain silicide shorts to body) others are more robust. If the output transistor is large enough and is designed with the same rules as the ESD device then it could be OK. You really need to discuss this with the (...)
Hi, Have a look at these posts * by t
Hey folks... What should I use to protect my electronic module (LDO 3.3V regulator, uC, RF transceiver) on automotive enviroment... This module will consume about 50 mA. I found this on ST site... is it good enough or should I add something else, like inductor, PI filter, and so on...
Please, give me detail circuit diagram and theroy for UNDER & OVER protection for electrical devices. Thanks, S.S.kendre