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https://www.allaboutcircuits.com/technical-articles/voltage-buffer-simulation-composite-amplifie r-simulation-boost-output-current-drive/ -- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

Hi, all, we had a bank holiday here, nicely positioned close to the weekend and I took the free time to play with my multi-IF3601 low noise...

Hi, all, we had a bank holiday here, nicely positioned close to the weekend and I took the free time to play with my multi-IF3601 low noise amplifier. That was not so funny because it features a negative input impedance over most frequencies, so with a suitable inductance on the input it makes a stable oscillator. Some observations: - Zin is negative also with the feedback loop cu...

I like to do the tricky parts of a pcb layout myself, rather than trying to explain it to a pcb designer. Actually, I don't know how parts...

I like to do the tricky parts of a pcb layout myself, rather than trying to explain it to a pcb designer. Actually, I don't know how parts should be arranged until I push things around for a while. It's chaos until something clicks. https://www.dropbox.com/s/rgjkb17itlkpud3/Z508A3_pcb1.jpg?raw=1 That has two 20 GHz $20 MMICS summing into a 20 GHz $350 distributed amplifier. That's sc...

Hi, I'm trying to build a 2-200 MHz isolation amplifier. For 13 dBm I need abt. 120 mA peak current, 70 mA quiescent. The circuit is a...

Hi, I'm trying to build a 2-200 MHz isolation amplifier. For 13 dBm I need abt. 120 mA peak current, 70 mA quiescent. The circuit is a voltage to current converter, followed by a double cascode. 2N3904 is too slow, BFQ19S is too hot, it would do 1 GHz, but brings me negative input impedance, gain peaks and so on. I'm playing with the usual ferrite beads, but that does not bring com...

Hi all, I am currently working on a range-switched photodiode design for use in our laboratory [1]. It took me a while, but I've arrived at a...

Hi all, I am currently working on a range-switched photodiode design for use in our laboratory [1]. It took me a while, but I've arrived at a design I'm fairly happy with (in no small part thanks to Phil Hobbs' helpful writings on the topic): My current draft uses a simple BF862 source follower at the summing node of a ADA4817-based 2 M?/2 k? transimpedance amplifier to bootstrap t

A long time ago I made a cable tracer from a coil of 2,000 turns of wire on an old solder spool, connected to a high gain amplifier that...

A long time ago I made a cable tracer from a coil of 2,000 turns of wire on an old solder spool, connected to a high gain amplifier that fed headphones. After using it for the job that needed it at the time, I put it away in a box "just in case". Today I realised that my watch was no longer on my wrist although I remembered putting it on this morning; a thorough visual inspection of the h...

I got a 5316 counter off ebay with OCXO and 1GHz channel. There's a differential amplifier/receiver in there, HP pn 1826-0589. Of course, the...

I got a 5316 counter off ebay with OCXO and 1GHz channel. There's a differential amplifier/receiver in there, HP pn 1826-0589. Of course, the x-ref lists I've found so far jump from 1826-0588 to 1826-0590. Either of those parts have nothing to do with amplifying. Anybody have a clue what this part could be? The BOM claims it's a TO-8, but the schematic shows 12 pin numbers... I'll take t...

Designing an RF amplifier. Concept is, high power, complementary cascodes for the output stage (with heavy class A use, but being PP, class AB...

Designing an RF amplifier. Concept is, high power, complementary cascodes for the output stage (with heavy class A use, but being PP, class AB is an option). 50 ohm output, direct drive, say 10W level. I happen to have a complementary pair that's not too slow (2SC2690A and 2SA1220A), and I'd like to maximize the bandwidth around that. The NPN side is fine, I have a 30V, 1A, 2GHz tran...

So we've got this custom product that includes a voltage-controlled amplifier. VCA chips as used in ultrasound and so on have nice low noise...

So we've got this custom product that includes a voltage-controlled amplifier. VCA chips as used in ultrasound and so on have nice low noise at the highest gains, but at low gain they stink on ice. The same is true of all transconductance-based VCAs unless you use a zillion stages. Sooo, we're faking it with a dpot, an op amp with a mux-controlled resistor ladder, and an LPC804 Cort...

Hi, I have a few questions about gain and noise in the transimpedance amplifier. I've been mainly reading Hobbs (2nd edition) and H&H AoE (3rd...

Hi, I have a few questions about gain and noise in the transimpedance amplifier. I've been mainly reading Hobbs (2nd edition) and H&H AoE (3rd Ed). References below are to those editions. Most importantly, thank you to the authors for these wonderful texts! === Rolloff of transimpedance === Hobbs Eqn 18.10 gives an expression for the transimpedance Zm, and states t

I use a 1210 X5R 25V 10% MLCC for input DC blocking. Supply is drying up and I want to place an order to support production for a while. In...

I use a 1210 X5R 25V 10% MLCC for input DC blocking. Supply is drying up and I want to place an order to support production for a while. In performing a Digikey/Mouser search I see there are now X7R devices in the same footprint. I know the X7R will be more stable under DC voltage which is an advantage *if* there is much DC on the input. The amplifier circuit has a 6 volt DC bia

Hi to all my fans, -------------------- see pic of possibly the most famous stereo power amplifier ever...

Hi to all my fans, -------------------- see pic of possibly the most famous stereo power amplifier ever made. https://cdn11.bigcommerce.com/s-6naz0isypk/images/stencil/2048x2048/products/3247/20471/5569873- 7432-5__81144.1510738289.jpg?c=2 The Crown DC300A was first released in the early 1970s and sold in large numbers, world wide. The letters "DC" refer to the fact it has response dow

Hey Folks, I need to design a broadband TIA for photo current amplification. I am using a LMH6629. I simulated the circuit in Tina-TI an it...

Hey Folks, I need to design a broadband TIA for photo current amplification. I am using a LMH6629. I simulated the circuit in Tina-TI an it is working pretty well for a feedback resistor of 330Ohm and a feedback cap of 4pf and a signal of 10MHz. However the simulation is showing oscillation if I increase the cap to something above 20pf. In my opinion it should be stable for higher caps and o...

This part, an 8 pin bridgable 1W audio amplifier with volume control input is going obsolete and last order date is end of this...

This part, an 8 pin bridgable 1W audio amplifier with volume control input is going obsolete and last order date is end of this year. When I designed it in around 10 years ago they were old then but plenty available. We will eventually need to design in a replacement. We are running these at around 9V VCC and they work great into a small speaker. 8 Ohms I believe. We also use...

Hi all. I'm running through some test of a phototransistor signal conditioner, and I'm facing with wild noise issues. The conditioning is a...

Hi all. I'm running through some test of a phototransistor signal conditioner, and I'm facing with wild noise issues. The conditioning is a basic TIA stage: http://i.imgur.com/PcgglKZ.png Feedback resistor is 5K, feedback capacitor is 470pF, negative bias is -12V, and photocurrent is in the range 8uA-800uA. The bandwidth should be about 50kHz. Opamp is OPA2277UA. Problem is that phototrans...

I've placed 22-ohm 0805 resistors in series with the HV supply lines in the latest version of my easy-to-build AMP-62 high-voltage amplifier...

I've placed 22-ohm 0805 resistors in series with the HV supply lines in the latest version of my easy-to-build AMP-62 high-voltage amplifier board. This version is often made with aggressive output current-limit values, e.g., 150mA. But it's intended that such currents last only a short time, e.g., to rapidly charge a capacitive load (during the rapid output slewing, the 22-ohms only drops ...

I've been looking into buying an Audio Generator (Sine and Square Wave). I mainly want this to run thru an amplifier to listen to the...

I've been looking into buying an Audio Generator (Sine and Square Wave). I mainly want this to run thru an amplifier to listen to the frequency repsonse of the amp and speakers. Nothing very scientific, just to see what these amps and speakers can do.... And on occasion to inject an audio signal into amp sections to dee if the audio is passing that stage. Originally I was looking at some ...

https://www.dropbox.com/s/tugwe4mnoj2ri80/Z508_AC_Coupling.jpg?raw=1 0306 cap, capacitive bump. 0603 cap, inductive bump. No surprise that the...

https://www.dropbox.com/s/tugwe4mnoj2ri80/Z508_AC_Coupling.jpg?raw=1 0306 cap, capacitive bump. 0603 cap, inductive bump. No surprise that the 0204 is best. In the 25 ps sort of domain, on FR4, there's no need to buy exotic caps. That 0204 is a 0.47 uF 16 volt cap. With 9 volts DC bias from my distributed amplifier, it loses 80% of its capacitance. -- If a man will begin with certa...

Looking for operating info on an ENI Verteq VNA-1987-21121 amplifier. Operating manual, schematics, anything you've got. Yes, I tried...

Looking for operating info on an ENI Verteq VNA-1987-21121 amplifier. Operating manual, schematics, anything you've got. Yes, I tried Google, and it wasn't my friend on this one. Thanks and 73--

The circuit linked below appears to be a conversion of a three stage inverting tube amp tube to a transistor circuit, powered by...

The circuit linked below appears to be a conversion of a three stage inverting tube amp tube to a transistor circuit, powered by 3VDC. https://app.box.com/s/dwflbolnqe58ra9c1kssqjuq14dulxo0 It appears to be intended to capture high frequency ambient signals and re-broadcast them. It may also be designed to self-oscillate to add a carrier wave. In any case, I would like to build it o...