Posts by Olin Lathrop
The RFIC manufacturer recommends to "add filtering caps" for high RF output cases. It seems your questions are really about this RF IC, not the oscillator. The oscillator itself seems to be prett...
That circuit is drawn rather obfuscated, but it does seem to make sense: Start by looking only at D1, D2, C1, and C2. Pretend D3, C3, and D6 don't exist. Although not drawn very well, this is ...
Is there a scientific way to estimate the resistance of a pogo pin? Ultimately there must be, but it generally requires knowing things you don't know. Worrying about the resistance of the barrel ...
When should a transformer core be potted? Whenever you need some of Mechanical ruggedness. High dielectric strength. Minimize vibrations (and therefore audible whine) from capacitive, inductive...
My first knee-jerk reaction was to use opto-isolators. There are some that have been around for decades and are unlikely to go obsolete any time soon. I wasn't previously aware of these "digital ...
It has two female inputs on the backside that are labeled as "Grounding". This is incorrect. Take a closer look at the two connections and you will see that the left is labeled "Antenne" and t...
I see that Monica answered your question directly. However, there is another point to keep in mind. Comments are not for content. That was supposedly the case at SE too, but was poorly enforced....
You should not be relying on the internal circuitry of whatever senses the 4-20 mA current. Note that the two implementations you show both use current sense resistors. The only difference is the...
Yes, you seem to understand the concept. From the case to the ambient air, there will be 1.3°C per watt across the pad, and another 2.0°C per watt across the heatsink. In total, there will be 3.3...
A higher voltage can be produced at 1:1 ratio because the transformer is being run in flyback mode. Unlike normal forward mode, the primary and secondary don't conduct at the same time. The input...
Your third equation defines impedance. Rearranged to solve for Z, it is: Z = V / I Note that this is exactly Ohms law when V and I are real numbers. In the general case of impedance, all th...
Follow the current. Q3 is a controlled current sink. Whatever voltage is applied to its base appears across R11 minus the B-E drop. That voltage on R11 causes a particular current to flow. That...
Those are good questions, and I don't have a single definitive answer for them. I'd start with putting an appropriate TVS (or maybe separate diodes to ground and 3.3 V) between C3 and S1. My reas...
My control system gets a signal representing the plant output, but that signal has a lot of noise on it. The control system goes nuts trying to react to the noise. I need to filter out the noise ...
Can anyone explain the theory behind this pin You have already done so yourself: used to give a common mode stabilization and thereby reduce radiated emissions As far as I know, that is exactly ...
What is a typical value for capacitance of a real inductor? "Typical" capacitance is a useless to design circuits with. It will also vary considerably by inductor size, geometry, and materials us...
That's a rather strange thermal relief pattern. It's also not clear where the hole is supposed to be. A proper thermal pattern has a plated hole and annular ring around the hole as usual. Then t...
I see you already have an answer based on the device physics. I'll answer that this means in a circuit. BJT (bipolar junction transistors) do work in reverse, at least somewhat. Generally, the c...
"Stream" and "memory mapped" should be defined in the documentation for whatever microcontroller you are using. "Memory mapped" can mean different things. It might be just a different way of sayi...
Whichever you choose. I notice that you deliberately made the gain of one transistor a little higher than the other. That is irrelevant. The positive and negative outputs don't depend on the pow...
Reasons this is sometimes done: To get higher power dissipation. To get higher voltage capability. To get lower parasitic capacitance. For 1 and 2 the "normal" answer is to use a resistor rat...
I always had trouble understanding the terms "digital" and "analog" A digital signal is intended to indicate one of a finite set of discrete states. The number of discrete states is usually two fo...
You haven't provided any context, so there is little to say about this particular design. For all we know from what you told us, this could be homework from a student that just made a mistake. How...
First let's define what a "Pi filter" is: The name comes from the inductor and two caps forming the shape of the Greek letter Π. These filters are used for EMC compliance because they attenuate hi...
The short phrase is trying to capture the two broad classes of topics here: Electronic things, like opamps, transistors, microcontrollers, 20 W power supplies, and the like. Utility-scale power sys...
