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46 Threads found on Bias Circuit Cmos
Hello everyone, I have been facing problem in designing a folded cascode cmos opamp. I have designed the mosfets aspect ratios for the amplifier circuit but i could not design the bias circuit. I admit i am not very good at designing circuits. so can people here help me with the bias (...)
I think he meant cmos IC biasing circuit.
I am a first time analogue designer and need help with my Gilbert cell multiplier(cmos 0.18um technology). The problem is that my circuit doesn't bias correctly.I work in low frequency. the output that I need, the plot of four quadrant of multiplier. *Gilbert cell analog 5 .options brief *********************Main (...)
Hi, I am making a supply independent bias circuit as shown in Razavi cmos integrated circuit book (Figure 11.5). I simulated the circuit but it does not seem to work properly. See output current vs vdd supply curve attached with this email. Can some body help? circuit has following W and (...)
Hi, all, I'm using the TSMC 0.13um cmos proccess. I would expect some influence to the frequency response, for example for one amplifier stage, when I was using a huge resistor as the AC coupling bias resistor for the next stage. But the simulation results show almost no influence, and I found that the resistor, for example rphpoly, has no paras
in Razavi's cmos book Chapter 12, see figure below 82262 how to bias the opamp properly since the opamp is configured with capacitive feedback (C2) at both phases? thanks!
hi... u can refere 1. B.Leung, “VLSI for Wireless Communication”, Pearson Education Inc,2004. 2. B. Razavi, “Design of Analog Integrated cmos circuits”, Mc-Graw Hill, 2001. 3. Allen hollbergue, "cmos-Analog-circuit-Design" 4. T.H.Lee , "the design of cmos radio-frecuency entegrated (...)
All outputs open circuit. The comparator inputs want to be at different potentials to avoid chatter. It doesn't really matter which, bias current is relatively constant. As long as the ground connection is close-in a direct connection is fine. If it's a long "antenna" or there's a chance of offset then a few-K resistor is OK, but probably unnecess
Hello all, In razavi's design of analog cmos integrated circuit, chapter 3, it states/shows that body effect decrease the output resistance. But I find it puzzling. I bias the NMOS source with a certain voltage, eg 0.3V. Setup 1: Base and Source are connected together to 0.3V bias. (No body effect) Setup 2. Source (...)
The cmos version of 555 has a supply current demand in a 100 uA order of magnitude, so it can't compete with the low power transistor circuit. 555 is designed for up to MHz rate, so it needs a higher bias current. But the output will a clean rail-to-rail squarewave.
Hi, I have a few questions on bias current generators and Bandgap reference voltages: 1. To generate a bias current why is a PTAT current generator used. The current will be proportional to absolute temperature so won't that affect the circuit performance. Instead shouldn't a bandgap reference voltage be generated and then use that (...)
cmos>>68R>>..|>1n4148... base add a 1k res between 1n4148 cathode and ground the 68R resistor limits any current from the cmos i/o more than desired the diodes gets rid of .7v the 1k to ground allows for the right bias lift up from diode cathode use a bd139 in this circuit
Break it down into pieces. Some devices are only used as capacitors. Some are only for limiting voltages and the rest is only a very simple bias and protection voltage generation circuit. It is basically what adamantiumxx told you to analyze. You can find analysis in any cmos circuit design book. You might want to (...)
good day everybody.. i'm doing simulation right now about high swing cascode current source. this is about the self bias high swing cascode current source. please refer below for the figure. (i found this circuit in cmos Analaog Design by Allen, 2nd edition page 133.) In this configuration, he eliminates an Iref, from the two Iref (...)
Hello everyone. I need to design this circuit for a full flash ADC 4 GS/s in 65nm cmos. There are some rules to do that? for example, how can I choose W, I bias and Rload for this circuit? please, I need a big help. circuit:
I have designed a LNA circuit in RFIC with charted RF cmos 0.18um process. The LNA's measured current and bias voltage agree with its simulated ones. Also, the LNA's input and output port have been matched well with VSWR<2 at 1.55GHz. However, the LNA's gain at 1.55GHz is only 5dB, far lower than the simulated vaule-15dB. Anyone can (...)
Hi, Id (M8 ) = Id(M9a) + Id(M9b) so vbias = Vgs value which gives Id(M8 ) considering the effects of Vds8 Practically u can find this Vgs value by plotting V-I curve for M8 you can refer to any books on Analog cmos design. Hope this helps. Thanks,
GIDL currents arises in the high electric field under the gate/drain overlap region. GIDL occurs at a low Vg and high Vd bias and generates carriers into the substrate and drain from surface traps or badn-to-band tunneling, (taken from: Kaushik Roy :"Low Power cmos VLSI circuit Design")
Hello. I need to design a substrate charge pump to generate a negative substrate bias. The picture shows a simple substrate pump basic cell proposed in the Baker Li "cmos circuit Design, Layout and anyone tell me any formulas to design this circuit
Hi Guys For most of the voltage bias points, they connect to the gate of cmos, so drive infinite load, but how to set the driving DC point. For example, you have a battery of 2V, your circuit working voltage is 1.2V@2mW, so how to set the DC voltage in this case. The only way I can think is to make the bias current big (...)