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77 Threads found on Stage Cascode Amplifier
The assumed first order gain characteristic isn't bad as an estimation. There's an additional cascode stage pole, but you can probably ignore it. The other expressions are however only right if C2 >> Cf, otherwise the amplifier output impedance matters. As a short cut, it's rather unlikely to drive an amplifier with (...)
Hello, I am attaching here a multi-stage cascode amplifier schematic operating at very high frequency at bw of 28GHz. A part I have understood about the circuit as following From RFin signal travels through L and C matching network then from source degenerated CS stage to cascode (...)
Folded cascode would be your current source limited gain stage. Class AB would be your source follower (or, a fancy-controlled common source) output stage meant to deliver any necessary current.
I am designing a stacked CMOS power amplifier using st65nm design kit. The device I am using is nsvt25_rf. While designing cs stage maximum Vdd I took was 2.5V. Can someone suggest the Vdd that should be used in cascode configuration (2.5V or 5V?). Is Vds value specified in design kit the maximum Vdd that should to given or maximum Vds (...)
I am designing a difference differential amplifier following the attached schematic. With a folded cascode first stage & Common Source as a second I am wondering how would the CMFB circuit look like? What i
Hi guys I have made a two stage opamp with pmos differential input and CS stage for the second stage in .18u technology. I got a GBW of 800MHz and I am trying to get near 3GHz. Equation says GBW=gm/Cc and despite increasing gm to even 2mA/V the GBW does not increase further. Any advice on how to increase the GBW. There is no constraint on (...)
gain of alone CS amplifier is -GM*rd. Using the simplified transistor model assumed in your gain expression (infinite output impedance), the additional cascode stage doesn't change the gain of the basic CS stage. Your circuit however implements additional source degeneration. With Rs = 200 ohm and Rd = 100 ohm, the (...)
When You designing two stage ota, the first of all You need to add a compensation network (e.g. Miller cap with nulling resistor or used a cascode compensation). Your amplifier is unbalanced - output transistor should be matched with first stage current mirror load. In addition the phase margin and GBW depends to feedback (...)
Adding a cascode stage in an amplifier increasing the output impedance. What the advantage of this? The main benefit of a cascade amplifier is better high frequency performance because the "Miller Effect" is eliminated. The increased output impedance might be a problem, not an advantage.
I have attached a picture of a folded cascode amplifier with class AB push pull stage. My question is regarding the SLEW time of the amplifier. During the 'internal slewing' when the compensation capacitors CM1, CM2 are being charged up, what is the status of the M4, M4C, M8A, M9A, M2C, M6 ? Do these mosfets operate in (...)
Hello, I have attached a folded cascode amplifier with class AB stage picture which is commonly seen in text books. I would like to know : * Supply VDD = 15v. On the NMOS side, the cascode nmos (M1C, M2C) are 30V devices and the bottom nmos (M5, M6 ) are only 5V devices. What is the special reason to do this ?? * (...)
Hi, I want to analyse the circuit below. It is an RF power DC mode: Assuming that Ld is ideal then there is no DC voltage drop across it. => VD2 = VDD. In the mean time, the capacitor is open at DC => no current flowing through Rb => VG2 = VD2 = VDD In
WHat is significance of cascode amplifier? why do we use cascode amplifier?..why to use folded cascode and why is that called as folded?...
hi, i'm designing an integrated k/ka-band power amplifier with cadence virtuoso which looks similar to this one: 90974 in my case the load inductivities L1 of the cascode stage are about 100 pH. i simulated the s-parameter stabilityfactor kf. it is below 1 for a very wide frequency range from 20 GHz to 70 GHz. the m
Hello, the amplifier in the attachment is a folded cascode with class AB stage. Is there a suitable 'current limiter' circuit architecture that you can suggest ?? I need to limit the max. current to + /- 10mA
Hi all, Given a millimeter-wave multi-stage common source/cascode CMOS amplifier. Which method would be the proper design: inter-stage conjugate matching or resonance load (adjacent stage should be place close in the layout)? For CMOS transistor, it is gate-source voltage controlled device, it is more (...)
the cascode amplifier,works by changing the input signals voltage into a current in the first stage. In the second stage the signal current is changed into a voltage. The advantage of this is that as the input impedance of the second stage is very low, the signal current develops very little voltage st this (...)
Make a Telescopic cascode for the first stage for high gain of atleast 300. This would be easy. A telescopic itself would give a gain of around 1000 if designed well. Make a Regular Common source stage as second stage with a gain of atleast 10. Also easy. Put appropriate compensation for stability. You can refer (...)
Hi! I am doing a class AB common source output amplifier with a folded cascode gain stage. The load is 1pF and 10 kHz. supply is 0-5V. the gain is > 70 dB Everything was working as expexted until I changed the DC voltage of the load. When loads are grounded the phase and gain are as I expected, but as I turn up the common mode load (...)
Hi all I just have a doubt on cascode amplifier. Is it really necessary to use the same dimension device for the cascode stage transistor in a cascode amplifier. If so, what is the reason and if not what are the benefits by choosing other dimension device. One more (...)