# Tag Info

18

"Rail-to-rail" is a marketing term used to describe an op amp whose dynamic range is able to reach the extremes of the supply voltage. This can refer to either the output or both the input and output. It is not possible for the output to exceed the positive or negative supply voltage (which is why these are commonly referred to in US-English as "supply ...

17

An output pin (GPIO) with both source and sink capability is one that can be used for driving a load up (towards Vcc) or low (towards ground). In other words, it is effectively a push-pull type output driver. The "high capability" means it can support a relatively low impedance load, providing "high amount" (40 mA per pin for ATmega328) of current from ...

16

That's a DIN 41529 loudspeaker connector. It's simple, it's polarized, so it was only a matter of time the Chinese used it for LED lighting power connectors.

14

A Push-Pull output is your normal CMOS or TTL-like output. It's either HIGH (IO pin is connected to VCC through a MOSFET), or LOW (IO pin is connected to GND through a MOSFET). The basic circuit of the output stage is as simple as: simulate this circuit – Schematic created using CircuitLab It is the technical name for any "normal" digital output ...

12

Your typical double transistor current limiter may be your best bet. Shown below is the top-side and bottom side versions. simulate this circuit – Schematic created using CircuitLab Note there is a penalty of about a volt drop with this circuit. Buy dual transistors in a single 6 pin package. The small resistor will cause the current to fold back ...

11

The resistor to ground is exactly as the description says so - to prevent the pin floating high and turning on the FET, thus making the motor move erratically/uncontrolled. Floating MOSFETs are bad, and because the "on" control of the FET is essentially just a capacitor with very low capacitance, it is quite easy for it to float up and turn itself on. ...

11

In general source degeneration resistor "adds" a negative feedback to the circuit (current-series feedback). In this case, we sample the output current ($I_D$) and return a proportional voltage in series with the input ($V_{GS} = V_G - I_D*R_S$). This type of a feedback increases $Rin$ and $Rout$. But notice that the MOSFET itself has a very large \\$...

9

Floating: neither pull-up nor pull-down. Your input goes effectively straight to the gate of a FET somewhere. Should be used with external driver or pullup/down only; don't leave it entirely floating to pick up ESD. Analog (output): not quite clear from the datasheet, but I'd assume this was the output of a DAC somewhere and can therefore take a range of ...

9

The main reason for using open-collector is so that several comparators can have their output connected together in a wired OR gate. All the open collectors can be tied together to a single resistor without any conflicts between comparators. This would not have been easy to do when your comparator has also the capability to source current at its output. ...

9

There is nothing in the specifications, nor in the internal schematics, that defines what the outputs of a JK flip-flop should be at power-on. The only way of getting a known state is to use the CLR input of the chip, which resets the whole chip into a known state. The normal way of doing this is to hold CLR low for a short period while the chip powers up, ...

9

This is a typo. The not in the Note (as transistor points out) should not be there. Then it makes sense. Be sure to tie off any unused input, but unused outputs are fine. Line in TI article, Designing with Logic, Note: Unused outputs of a device should not be left unconnected (open). The title of the section where this line is referenced is: ...

8

Usually we're concerned with how much loading can be put on the output and still have it function properly. The output swing specification will be at a specific load resistance, usually load is between the output and ground on both dual and single-supply op-amps. For example, the dual-supply OP-07: You can see that over the whole temperature range with +/-...

8

I'm using this very often. With little modification, you can adapt to other DC votages or polarities. With good fuse only green led lights. When fuse is blown only red LED light up. Also you can use a dual colour LED with common cathode instead of two single.

8

It's called a Zobel Network. The purpose is to neutralize the effect of the inductance of the speaker. The 250uF simply blocks DC from the output bias point of the amplifier output stage, which normally sits around half the supply voltage with no output, and swings from close to GND to close to the positive rail when it is providing full output.

8

The two diodes within the dotted line represent the bulk parasitic diode in parallel with each MOSFET as per this diagram of a solid state relay (SSR): - what do the diodes facing opposite do When both MOSFETs are activated the MOSFETs will offer low on-resistance and shunt their respective parasitic diodes. You need two back-to-back MOSFETs in a SSR so ...

7

Is there a way to find the transfer function from only your input and the steady state response? Clearly, no. Steady state response means assentially the 0 frequency response. Obviously systems can have the same 0 frequency (DC) response but various responses to other frequencies. For example, consider a simple R-C low pass filter. The DC response is ...

7

No, you cannot "play music" just like that through the USB D+ and D- datalines. USB is a two-way data communication protocol so if you want to use it to play music you have to use something that can output audio and has a USB connection. Also your transmitter needs an analog audio signal as input signal, that's why you need to connect it to your soundcard. ...

7

Rail to rail means that the op-amp inputs and outputs can operate near the supply voltages. Many op-amps that operate on relatively high voltage rails (I.e. +/-15v) can only drive the output to within 3 or 4 volts of the rail - for example, with a bipolar 15 volt supply, the amp may only be able to drive up to +/-12v. Same goes for inputs. The op-amp input ...

7

The image is self-explanatory:

7

Note A says the minimum load current for this circuit is 30 mA. If the circuit will not always have a load of 30 mA or more, you need a resistor there to draw 30 mA and satisfy the minimum load requirement. Without the 30 mA minimum load, the the circuit will not regulate correctly - the output voltage will probably rise. The LM317 by itself (without the ...

7

Take a look at the ProFET high-side driver ICs. These devices give you a switchable high-side drive with protection from all sorts of things, including output over-current. You can find and select ProFETs readily enough from distributors. Have a look at the BSP752T, which is cheap, small and can be driven directly from 3.3 V or 5 V logic.

6

I always thought of comparators as the simplest A-D converter. You may want a different supply voltage on the analog side (maybe +/-15V or something) and the output going to a different digital voltage. (+5 V perhaps.) The open collector lets you easily adjust the output voltage reference.

6

If you find a way to do this then you will instantly become the richest person in the known universe. Voltage and current combine to form "power". The power is a finite amount. If you have 5V at 100mA then you have 0.5W (P = IV). If you want to get 200mA out, then you want 1W out. To get 1W out you will have to put 1W in. In order to get 1W in you will ...

6

You'll need to know the characteristics of the semiconductors, too. The basic idea is straightforward. You calculate the voltages and currents throughout the circuit for one operating point. Call the nominal load I0, giving an output voltage of V0. Then you draw an additional load, say I0 + ΔI, and recalculate the numbers, which will yield a ...

6

Just connect it - and only it - to the MSP device pin. A "push pull" output is one that can't be shared with other outputs (to save I/O pins) and doesn't need a pull-up or pull-down resistor. Which makes it the easiest sort to use. An "open collector" (or "open drain") output can only pull the voltage down to 0V, but not up to +V. This means it can be ...

6

The more current you source or sink through a pin, the more the voltage deviates from the ideal voltage. Here is what the datasheet of some random microprocessor says about the relationship between output current and output voltage (you should find such specifications in any datasheet):   The question is not so much how much current the pin can handle (if ...

6

Digital The first step is to make sure you really need 5 V output. Many digital inputs have a low enough minimum logic high threshold so that 3.3 V is solidly high. If you really need 5 V logic signals, use level converters. These are small, cheap, and readily available. They have a split power supply. You power one side from the 3.3 V supply and ...

5

The versions of the IN and OUT instructions which include an I/O address only allow the bottom 8 bits of the address to be specified in the instruction. For that reason, most Z80-based I/O hardware ignores any address bits beyond the bottom 8, and in most cases programmers don't worry about what the processor does with the upper 8 bits. In actuality, the ...

5

The address bus of the Z80 is 16-bits wide (bits A0 through A15), meaning it can address 65536 locations. The low 8 bits of the bus are bits A0-A7, which can address 256 locations. Each of the I/O ports connected to the Z80 has a corresponding address of 0-255 (256 total addresses). Only one port responds to a particular address. If the contents of ...

5

It's usually called Output Current. Parameter "Io" on this TI part, page 4. ADI calls it Maximum Output Current or "Iout", page 3. Occasionally, it is called Short Circuit Current or "Isc" like in this Linear part which is 5-9mA depending on operating conditions, pages 4 and 6. It is a slightly roundabout way of saying even if you short the output with 0 ...

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