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Bandgap And Regulator

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31 Threads found on edaboard.com: Bandgap And Regulator
Hi, I thought a regulator error amplifier needed a Vref on Vin+ and the feedback on Vin-, maybe I'm wrong for your design. What's a bandgap core? Home-made or manufactured? I ask as it's nice to learn things, and discrete voltage references are something I like but know will never be any good, (...)
zeners are not efficient nor stable compared to bandgap reference diodes used in all LDO's (LM317 type and many others) Zeners must draw more than the worst case load to ensure when loaded there is still enough current to get past the knee in the zener. Then when no load, that current * voltage can lead to thermal problems for high (...)
Hello, Attached is a picture of an LDO schematic seen in the IEEE paper: A 1.21V, 100mA, 0.1uF - 10uF output capacitor LDO voltage regulator for SOC applications. The vref is a bandgap voltage (1.2V) and the resistors R1 and R2 are adjusted to deliver the desired output voltage (2.5V). The VDD = 3V The (...)
1) You can't. Precision bandgap references are almost always trimmed for accuracy. 2) I don't think there is any reason, other than it being a nice rounded numbers that industry partners thought was good for standardization of ADC/DAC references and regulator feedback margins. 3) Vbg = Vbe + k * delta(Vbe) (...)
There are two tricks for low noise voltage regulators: 1) choose one that allows you to put an external capacitor across the bandgap reference, such as LM723, NCP623, etc 2) Have enough input shunt capacitors (and maybe input series inductance or small resistance) to form a lowpass filter for any input noise above 10 (...)
In a power IC the bandgap and any cascoding is unlikely to be significant in the end, area-wise. It's the power devices' area. The current for a reference and housekeeping analog should not need much device width. Stacked MOS diodes and a resistor make a good enough shunt (...)
How to setup in laboratory to test PSRR of a voltage regulator / bandgap circuit
Since the input power is fundamentally limited I would go with a shunt regulator, right after the rectifiers. A very low power bandgap and shunt transistor. Or even just a simple FET stack (say, 3*VT) maybe with a high ratio current mirror at the bottom so you have usable drain headroom. Question is, how good (...)
i think i need a pre-regulator circuit . tks Right. As most bandgap ICs are rather low power devices, a simple resistor - zener diode combination should do. BTW: Such questions (nothing common with Analog IC Design & Layout) should better be asked in this forum .
first you can generater the internal VDD by regulator and the bandgap can be use VDD for power supply
In conventional bandgap topologies the minimum voltage is VBE+a*VT+VDSAT It is the series path of the parasitic PNP, a kT multiplier and a PMOS regulator current output. In a non-curvature compensated band the absolute temperature coefficients of VBE and a*VT should cancel (...)
Can I use a voltage regulator before a bandgap to further inprove PSRR? In this case, it create a loops between bandgap and voltage regulator, where bandgap supply reference voltage to regulator. Anyone have experience in (...)
Now I use high voltage process, Vds can reaches 30V, Vgs can't exceed 5V, then my previous method using high voltage bandgap, OP, and power mos to generates inner votlage 5V is impossible, can anyone give me some instruction or suggestion of generating inner voltage 5V, thanks!
Hi Everybody, I think I have to make it straight for everybody. I have designed Opamp, bandgap, regulator, Rectifier and ? with HSPICE and also checked the simulation with Spectre, and silicon results. As you may know, BSIM models are the most accurate models exist for MOS transistors. (...)
what is the best books/papers on bandgap voltage reference? please give me some advices, thanks.
For any DC-DC converter, there is a feedback loop to sense the output voltage and apply either more or less input voltage in order to regulate to the desired output. Usually just an op-amp comparing an internal reference voltage (bandgap voltage) to a feedback pin (FB). A linear regulator uses a pass device operating in (...)
CMOS shunt regulator with bandgap reference for automotive environment IEE Proceedings - Circuits, Devices and Systems -- June 1994 -- Volume 141, Issue 3, p. 157-161 thanks
Hi, My knowledge in analog design is very limited. Thus, can someone please tell me what is a bandgap? why is it so important in Analog Design (mix signal)? Highly appreciated Thanx in advance, -no_mad
Increase your startup helper current injection and switch it off after the bandgap reach near its full voltage.
bandgap is a kind of circuit to provide a temperature independene voltage reference. Voltage regulator is a circuit to keep a node voltage constant. and usually it require a voltage reference.
I need design a bandgap reference of 2.485V or so ,my boss said he need torlerance is ?2mv ,i can't reach it beacause The TC≈4ppm at 2.485v bandgap reference ,at the same time ,temperature -40~125,vcc 4~6.5 ,PSR about 100ppm.. although the bandgap cann't be desgin ,but i want to try (...)
low quiescent current LDO regulator how low current ?? 1ua or 0.1ua ?? we can easy design OPA or bandgap work on < 10ua .. if you want let you LDO work on < 1ua , maybe bandgap have some problem . for small current and Vbg keep 1.2v you need large "resistor" in chip .
A. Internal high voltage management: a. Charge pump: positive and negative b. regulator c. Bias generator (voltage bias: bandgap reference, tyipcal; current bias: current mirror) d. Voltage boost (for read operation) e. Current limitter (avoiding latch-up) B. HV switches -- for well-bias control (...)
hello every one, i need to design a low noise LDO linear regulator whose noise is lower than 20?Vrms(10~100KHz). i have adopted a low-pass filter to filter the noise of bandgap voltage, and i eager to know how to reduce the amplifier noise. how shoule i do and especially, what structure can i choose. thanks (...)
Specs for design: CMOS tech forced to use bandgap and a ballast to build up the simple regulator input 5V+/-20% output 2.5V +/=1% current <2mA Ro < 0.05 Ω Robg < 1 Ω temperature coeff kT < 500 ppm / °C Any design doc or school project report will be very helpful. thx for share!
hello all: i am designing a vco, the structure is regulator(bandgap+op), V-I converter and CCO, but i found that even with noiseless power supply, the jitter of the vco is much more worse than design the vco without regulator(only v-i converter and cco). i am really confused. wo (...)
I can offer the following idea: a high input voltage low dropout regulator with output voltage about 1.6 ... 1.8 V and low input voltage bandgap. What technology you will use? 0.6u, 0.25u, 0.18u or others?
use bandgap and OP to make a regulator, then you can get a stable, low noise voltage supply. you can get high PSSR double voltage supply is not a good choice i think
Gurus, I need to design a voltage dectector circuit and the supply voltage range is 1.6v~6.0v.But I have no bandgap reference voltage as my reference, can anyone give a hint or some reference sources? One more thing to add: suppose the voltage range is roughly divided into three parts: 1.6v~2.5v,2.5v~3.8v,3.8v~6.0v by two (...)
Hi How about your LDO speci ?? I ever design a LDO use bandgap + OPA buffer and driver "large Pmos " , becuase Pmos is large and R_on samll V_drop < 1v .. but this chip current < 1A
I am designing a regulator. which uses a close-loop opamp and a bandgap to get double or high output voltage. But in my design, since output has accurate require, so the opamp open-lop gain must be enough high. So I use fold cascode (first stage) + PMOS+two resistors (second stage). But the main pole in the first stage (...)