9

Those old bipolar processes could only be used to make crummy lateral PNP transistors with quite low gain so not very good for high current. Using all NPN, especially those NPN, transistors is bad (because of the extra Vbe drop), but not as bad as it would be with monolithic PNPs. Popular? Probably for legacy applications and hobbyists, but I doubt any ...


3

Is it because the table is stating the maximum? Yes. That's what 'Max' means. If so, what factor can cause Vce to change so much given that Ib and hfe are the same? Hfe isn't necessarily the same. Internally the Darlington is a concatenation of two transistors. Due to process variations the current gain of each transistor can vary widely, and is strongly ...


3

Looks like 90,000,000 Hertz Oscillation, on top of your 10,000,000 Hertz input. Figure 39 shows ringing near this (90MHz) frequency. With this much gain_bandwidth, its easy to have oscillation. Notice Fig 62 about capacitive loading. ============================== Use a Ground Plane. It you are not using a Ground plane, on a PCB, then stop and use a Ground ...


2

The fact that the pins are listed by name in the package spec, but not further defined, indicates to me that they're either ports for automated end-of-line testing or for diagnostic purposes. Less likely, but quite possible, is that they're special purpose functions such as fine adjustments or reference voltages that are used only internally or by a few ...


2

In your H-bridge schematic, the same signal is being used to drive the bases for the upper and lower transistors. Because the top ones are PNP, and the bottom are NPN, the tops will conduct when the signal is low, and the bottoms will conduct when the signal is high. The L298 schematic shows that inputs for the lower pair are inverted. That's the little ...


2

If the schematic is to be believed, that encoder has mechanical switches. That means that it doesn't need to be powered -- you just need the pull-up resistors so that when an encoder switch is open, the corresponding pin is high.


1

The led is connected to GPIO2/UART1_TXD as seen in the Chinese datasheet https://docs.ai-thinker.com/_media/esp8266/docs/esp-01s_product_specification_zh_v1.0.pdf It flashes on power on because like all esps the gpio2 is toggled during boot.


1

So the thing is that it is much easier to move electrons than to move holes. So a PNP has to be 3-10 "better" than a regular PNP to handle the current a NPN transistor can handle. That is the reason in the real world people prefer to use NPN transistors. Bottom line, You can have a PNP transistor that complement a NPN OR you can have 3-10 regular ...


1

It appears to be a voltage regulator: http://www.elm-tech.com/en/products/voltage-detector/elm75-series/


1

The encoder is literally a mechanical switch (or 3 switches if you prefer- the two phased encoder switches and the independent push switch). Here is what is inside one of them: The inner two fingers are connected to the center terminal. The outer bifurcated fingers go to the two outer terminals. Not shown is a dome contact that bridges the two inner ...


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