# Questions tagged [units]

A specified amount of a quantity (e.g. voltage, current, power, time, etc.) by comparison with which any other quantity of the same kind is measured or estimated. The standard system of units is the International System of Units (SI).

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### LDO units for noise [duplicate]

In this Link, on page 6,they have mentioned the LDO noise in terms of uV/(sqrt)Hz. Can someone tell me what does this unit mean and how to understand this unit?
161 views

### Battery capacity in mWh instead of mAh [duplicate]

I know that the capacity of a battery is expressed in mAh, i.e. A/s (international system of units). Today I used a command in PowerShell (*) in order to get the battery capacity, but the unit of ...
106 views

### Why are we able to ignore the henries, Hz, farads, siemens and ohms when calculating the characteristic impedance of a transmission line? [closed]

I have seen calculations, and every time we just take the coefficents of these values and end up calculating a simple complex number. The units all equate to various exponents of area, second, metre ...
91 views

### Schematics Standard for Space between Value and Unit

On electrical schematics, is there a standard for whether there is a space between the numerical value and unit symbol? I can find standards that require it in general writing, but none that ...
26 views

### How to interpret the “surface power density” of a battery/capacitor

I’ve come across this research and one point of representing a power output confuses me: This enzymatic fuel cell is based on non-immobilized enzymes that exhibit a maximum power output of 0.8 mW cm−...
85 views

### 1-dB compression point is in the range of -20 to -25 dBm

I am reading the Razavi's textbook RF Microelectronics 2nd edition p. 18. It says 1-dB compression point is typically in the range of -20 to -25 dBm (63.2 to 35.6 ...
276 views

### How to convert amplitude (V) to dB (V^2/Hz or V/sqrt(Hz) or V?)

I took the FFT of a signal and am currently plotting amplitude (V) vs. frequency (Hz). I'd like to change the Y-Axis units to dB. How would I go about doing this? What would be the units? It is from ...
1 vote
553 views

### What is the difference between "Storage Temp", "Ambient Temp" and "Operating Temp" mean?

To my understanding, ambient temperature is the temperature of the surrounding area while the unit being worked on is powered. While operating temperature is the temperature of the unit itself under ...
85 views

### In semiconductor physics, how can we know which units to use for Boltzmann's constant?

I'm working through Example 3.9 from Sima Dimitrijev's Principles of Semiconductor Devices textbook, and I'm not sure how to know which units to use for k in solving for $v_{th}$ in part a. The ...
52 views

### capacitor unit is not specified

I am currently working on a circuit but I can't figure out the non-polarized capacitor values, since some of them are not clearly specified as unit magnitude. Some of them are: 100, 500, 180, 5.6, 56, ...
61 views

### How to recalculate amperes to amperes/micron (transistor characterstics)

I measured the transfer characteristic of P-type FET (so I have drain current versus gate voltage.) The authors usually present results in μA/μm (microampere/micron) versus V (volt.) Because I have ... 86 views

### How does Ohm disappear in noise/power spectral density unit?

Power spectral density is commonly expressed in Watts per Hertz ($W \over Hz$) or $V \over \sqrt{Hz}$. When I try to derive these for a resistor I get confused on the units. If we define noise ...
1 vote
160 views

### What does Nu (ν) prefix mean?

Stumbled upon this in ZVN4525E6 datasheet: Zero Gate Voltage Drain Current (IDSS): 35 νA @ VDS = 250V, VGS = 0V The letter is U+03BD and it is not in any common unit prefixes that I know. My guess ...
33 views

### Units of PID for car' velocity?

I'd like to duple check from units of PID gains for the velocity of car. This my equations for PI controller V (m/s), kp (1/sec), ki(1/sec^2), kp' (radians/sec) , ki' (radians/sec^2) and kd (no unit)...
466 views

### What is the meaning of VFS

I am working with a Dataq DI-1100 whose specs tout: "The analog inputs offer a fixed measurement range of ±10VFS..." VFS looks like a unit, but I find the language confusing. Researching turns up ...
790 views

### How to convert between G and mV/g of sensitivity?

I cannot for the life of me understand how mV/g or LSB/g can be related to the g sensitivity. For example, how can I find 0.0025 G sensitivity accelerometer given the sensitivity in mV/g? I haven't ...
231 views

### analog values to ppm

How to transform a set of analog voltages from V to ppm/K? I have to use this to calculate the temperature coefficient of a bandgap. Is the derivative the same as the temperature coefficient ...
66 views

### Why is the Farad unit so large? [duplicate]

I have wondered this on and off for years, and was prompted to find out the answer: Any time I've seen capacitors, they're listed with milli- or pico-Farad ratings. I understand that, nowadays, we ...
550 views

### Compare white LED radiated optical power: lumens vs milliwatts

I'm trying to compare the brightness of various white LEDs, some of which are listed in lumens and others in milliWatts (this is milliwatts of optical output, not watts of electrical power consumption)...
220 views

### Inconsistency in Values of Laplace Transformed Current when Changing Units

I was trying to convert the units of the following current in Time Domain and Complex Frequency domain (s-domain): $$i(t)=20\cdot e^{-t}H(t)\,\,\,\,\,\text{[mA,ms]}$$ Where $\text{[mA, ms]}$ ...
2k views

### What units are kpts?

I am parsing data from a Siglent SDS2000X oscilloscope. The first chunk (0x00 - 0x003) is for wave_length. The data sheet ...
55 views

### Can I represent the value by using this unit [closed]

I want to represent this value in a better way for my report. This value is 3.1x10^-4 the unit is dBi Can I rather represent this value using this: 310 udBi The u in udBi is micro dBi
64 views

### What are the units when solving Transmission Line iterativelly?

I would like to know the conductancee,$C$, and capacitance,$G$, of my lossy transmission line which is configured as an open circuit. In such a case, I know that the expression that defines the ...
2k views

### Altium designer, changing from imperic to metrics primitives won't work?

I'm using a trial on Altium, where for I guess support ignores me (Altium Designer version 19.0.14). (I really hope it's better for real users if someone can confirm that, it would be most ...
128 views

37k views

### Transform pulses per second (PPS) to RPM

I have a stepper motor that turns at 5000 PPS and has a step angle of 1.8º. What would be the formula to transform these PPS into RPM?
1 vote