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Startup Circuit For Bandgap

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25 Threads found on Startup Circuit For Bandgap
Add some deliberate leakage (a very low current source or large resistor) to prevent it starting. Then add the startup circuit and check it does start. You may be able to do it with "initial conditions" although I usually add deliberate leakage. Keith
It's a normal zero current startup circuit I think, and I want to use it in a low power bandgap. But someone told there's startup risk in real chip. Can anybody tell the detail analysis and how to simulate it. 78546
Hi Guys: I am working on a bandgap circuit for a internal regulator in a DC-DC converter. The core circuit is a simple BROKAW bandgap circuit and i need a startup circuit for it.The problem is the input voltage is from 5~23 and the high (...)
this architecture is bad for low voltages. I like it since it is reliable. In your case you probably will have a bit high current through startup circuit - but you can fix it. Temeperature coefficiant - you can try to play with 1:n ratio. I noticed in my case that if I use usual 1:8 or 16, it does not work well so I went to 132 and made my (...)
Will the bandgap ref work well if I add 2 cap and 2 res in the circuit? startup without any problem? stability for work?
hi, would you pls suggest a startup circuit for Conventional BGR,which consumes less current(in nA) and improves the response of the bandgap? Thanks
I designed bandgap voltage reference and startup circuit for it. I have read topics about BGVR and startup. I verify startup this way: make Vdd constant value (or use vpwl source and ramp on Vdd), set initial conditions for nodes and make transient simulation. Vref (...)
Hi Surianova, Yes in this circuit u very much need the startup circuit... This circuit has two stable states one with zero current and other one with defined branch currents... and the second state is desired. So to pull it away from first state and pushe it into second one we need to inject some current into its branches
Try using a schimitt trigger to genarate a pulse use that pulase to urn on the mos connected to which ever node u want to inject current into... You can modify the "on" time of pulse according to ur worst case ... Once the pulse goes off startup mos is off. This the basic idea... Ihave implemented in my bgr .... It works fine!
go for the bekar book for startup circuit
Do you know any book or ref to design the startup circuit for bandgap both in cmos and bicmos process. Please advise. thanks
hi can anyone of u suggest me a good paper or a link to design the startup circuit for the bandgap reference. If u have the circuit then can u pls upload it. thanx in advance
I need startup circuit for bangap voltage reference and value for R1 and R2. VDDA=5V
There are few such materials about startup circuits for bandgap in IEEE. Where can I find relative materials? Thank you there is one start up circuit in the chaper of bandgap in Razavi's book
Does the brokaw-cell bandgap reference need the startup circuit?? Thanks
If a current reference circuit doesn't exit zero solution, does it need a startup circuit or not?
1. startup cap. 2. it must be compensation cap of the feedback loop.
for the startup circuit below used for bandgap I have found that for a fast ramping of supply voltage (10us) it takes a while for the bandgap voltage to reach steady state >10us, under different corners. However if you put a MOS cap at the current mirror (...)
Is that possible to design the power-down and start-up circuit for the bandgap voltage reference at the same time? When I add the startup circuit for my bandgap, then the power-down isn't work anymore. Anyone can recommend the paper or examples about badgap with both of (...)
for a bandgap, i have simulated some parameters, such as: 1. the PSRR; 2. the output impedance; 3. the input referred noise; 4. the temperature coeffient; But the three sides : startup circuit, frequency and stability . i do not know how to simulate them. for startup (...)
I consider what you think is right. Without the startup circuit the bandgap reference circuit has two stable state, so you must use .ic command to set the circuit to another stable state. So with or without the startup circuit you can see the difference.
I have a bandgap with 2 startup circuits. When I run a transient analysis it takes very long to simulate. This has to do with the output waveform shown below. Is the circuit unstable? Or does it has to do with the 2 startup circuits? By the way I am ramping the Vdd (...)
If the A or B is used as bias for gate of PTAT current, i think the circuit will not work. Generally , the statup circuit generates the current for core circuit, once the core circuit work normally , the startup circuit is isolated from the core (...)
it can work. it design for a low supply voltage. you should add a startup circuit at the gate of Q12&Q6 or Q16&Q3
The main circuit is the PTAT core. It is enclosed into a regulation loop which try to equalize the currents I1 and I2. The resulting current IPTAT=I1=I2 is the PTAT current. The equations for the PTAT circuit is I1*R+VT*ln(I1/(a*IS))=VT*ln(I2/IS), "a" emitter area ratio the solution for I1=I2 is (...)