19 votes
Accepted

Why datecode is SO IMPORTANT to chip manufacturers?

Date codes (and sometimes batch codes which are usually on the packaging) are important for traceability both for the device manufacturer and the customer. In safety critical applications (such as ...
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  • 21.5k
19 votes

What is ohm joules unit used for?

That's not J for joules. It's probably J for 5% tolerance. The component is just a 10 mΩ resistor with a 5 W rating.
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  • 4,706
17 votes

PCB Logic Board Reference Designator "E"

IEEE Std 315 suggests that you use "TP" for testpoints. The single letter "E" can be used for many things, including "circuit terminal", "electrical contact", ...
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17 votes
Accepted

PCB Logic Board Reference Designator "E"

It's a pad for a flying probe test (which happens at assembly and you can see indentations from a probe or meter, if this is a production board then it's probably a flying probe test point). Flying ...
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  • 63.7k
17 votes

What is ohm joules unit used for?

"J" means a resistor value tolerance of +/- 5% as per this site. The resistor in question has a value of 10 milli-ohms (\$m\Omega\$). It also applies to capacitors as per this wiki site: -
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  • 384k
14 votes

What do capacitor markings in dash-dot style mean?

After having found out that the capacitors at hand were manufactured by Panasonic (by searching the web for similar capacitor images; for instance, these capacitors look quite similar: 6224634 and ...
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  • 415
8 votes

SMD LED polarity marking: is the cathode marking standardized?

It is entirely per component manufacturer, and when the PCB is manufactured some companies will ask that component placement overlays are given with designators are provided and polarity marks for all ...
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  • 6,198
8 votes

Ceramic capacitors: how to read 2-digit markings?

The yellow green capacitors are Philips brand capacitors introduced in the 1960's. The top markings are: Green: Temperature coefficient -330 ppm/°C. Tolerance -20/+50%. Capacitance value range 1nF to ...
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  • 81
8 votes

What is a good methodology to identify small SMD components?

I'm surprised noone mentioned the various SMD codebooks [for active components] one can find a google search, e.g. the largest seems this one. I've identified fairly obscure Ricoh chips [voltage ...
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  • 14.1k
8 votes

SMD diode identifying marking 96

Rohm RB055LAM-60 Schottky Barrier Diode in SOD128 Package with marking code 96. The how: Firstly, what package is the diode in - knowing the package limits the search massively. In this case it's a ...
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8 votes

Having trouble identifying value of inductor, what is its inductance?

From the photo it looks like 10uH +/-10%. The band color appears to be silver (not grey/gray), plus 80uH would not be an E12 value (8.2uH would be) and brown is a rather unlikely tolerance (1%) for ...
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8 votes

PCB Logic Board Reference Designator "E"

Test point? That's the designation we use for such things. Edit 1 Note, we also use "E" for the uses Elliot mentioned in his comment. I'm gonna venture a guess that someone along the way ...
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  • 7,224
7 votes
Accepted

Why are capacitors usually marked on the negative terminal, not positive?

Why are capacitors usually marked on the negative terminal, not positive? Here some polarized capacitors: - Now you tell me which is the dominant polarity marker?
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  • 384k
7 votes
Accepted

How to identify SMD device marked LEFBV?

It's an IRLML0060TRPbF N-channel MOSFET Maybe, anyway. From the International Rectifier (now Infineon) datasheet, it matches your pinout: And the markings seem very familiar, too: L̲...
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  • 2,328
7 votes
Accepted

MKT capacitor with ohm value on case markings

I would like to provide an alternative answer, as to me it makes no sense to have a complex impedance of 0.25J + 200 Ohms printed on a capacitor-looking device, when I know that components that are ...
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  • 89.6k
7 votes

Unknown SMD Component

The usual search from s-manuals (https://www.s-manuals.com/smd/aa) didn't bring useful results. The part looks like a low voltage op amp judging from the schematic. The right-hand side sub-circuit ...
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7 votes

Unknown SMD Component

This is roughly how that circuit can be re-drawn: simulate this circuit – Schematic created using CircuitLab And here is it re-drawn to be easier to follow: simulate this circuit
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6 votes
Accepted

Reverse engineering a high side MOSFET driver SMD circuit board

Drawing the schematic in a more conventional way usually helps at understanding it better: higher voltages should predominantly be on top and signals should flow from left to right. simulate this ...
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  • 8,334
5 votes

What do the "F+" and "F-" pins on a power supply unit stand for?

My guess is that the media player used a vacuum fluorescent display (VFD) and that the -24 V was required for that. Figure 1. Vacuum fluorescent display. Source Wikipedia commons. +5 V is clearly ...
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  • 160k
5 votes
Accepted

Radial capacitor marking

333 = 33*10^3 pF = 33 nF 235 RCN is MFG date code and factory code for traceability e.g. 23rd week of 2015 RCN could mean any location, unique for each OEM.
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5 votes
Accepted

Capacitor Numbers, What do these markings mean?

I would agree its a 330uF 16V capacitor. The 282 appears to be a production or lot code. The information is found in datasheets, so you would need to determine the manufacturer and series to be sure....
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4 votes

SMD LED polarity marking: is the cathode marking standardized?

I believe that PCB manufacturers are aware of the fact that surface mount LED can have the tab on the Anode side. I have worked before with several manufacturers and they have always asked about the ...
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  • 377
4 votes
Accepted

SOT 23 package marked as A1⌐

Well, a quick Digikey search for "baw56" does turn up double diodes in a SOT-23 package. Of these, at least Fairchild and NXP sell them with A1* case markings. I'm not certain exactly which ...
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  • 664
4 votes
Accepted

SMD Component Identification 6 pin with diode properties

"K5" identifies the PESD5V0S4UD, a 5 V ESD protection diode array made by Philips NXP Nexperia:
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  • 14.6k
4 votes
Accepted

What does the reference designator DB mean when printed on a PCB?

Judging by the silkscreen symbol , it appears to be a BIdirectional Tranzorb or TVS which has bipolar Zener diode like properties useful for spike clipping. DB = Diode Bidrectional vs unipolar. A ...
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4 votes

What is this component? Marked R5

I think bidirectional or unidirectional TVS diode, but not sure. Because there are many in series next to what looks like a bus. Since the board is so old it is unlikely that you will find the SMT ...
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  • 63.7k
4 votes

Old capacitor markings (M) letter - actual capacitance

M is also used to indicate +/- 20 percent tolerance and this is the most likely meaning in this case. In this era a fractional value always meant microfarad. (Curd seems to be a prankster.)
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  • 877
4 votes
Accepted

What is the difference between these two IC suffixes: EUKG and IUKG?

The "I" is guaranteed over the full -40C to +125C range, while the "E" variant is guaranteed only from 0C to 85C.
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  • 17.7k
3 votes

Transistor with S250 marking

It appears to be a BS250 P-MOSFET. Here's one with similar markings at bg-electronics.de
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  • 51.4k
3 votes
Accepted

SMD transistor marking

It is a date/manufacturing code. Does not change pinout in any way. Look at this datasheet:https://www.mouser.com/ds/2/308/MMBT4401LT1-D-108598.pdf
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  • 1,729

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