Questions tagged [surface-mount]

Surface-Mount Technology (SMT) refers to the way components are mounted on a PCB: SMDs (Surface-Mounted Devices) have pins or contacts which lay on top of the PCB's pads, without the need for holes in the PCB.

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196 views

Tolerance on SMD Aluminum Electrolytic Capacitors

I'm searching for some polarized surface mount device capacitors on lcsc.com and notice that they only have tolerances of \$20\%\$ tolerance devices in their catalog for this type of SMD device ...
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1answer
229 views

Component identification (SMD)

Help me identify this component: test results identify it as a diode. I believe the manufacturer is Vishay, but I can't find anything when I search for it. There is a label placed on the component: "....
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1k views

MLCC - Can I use high voltage rated caps for very low voltage scenarios?

Is there any important reason why I can`t use high voltage mulilayer ceramic capacitors for low voltage scenarios? For example 50V or 100V rated MLCCs for 3.3V DC applications? I have bad eyes, and ...
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83 views

What ceramic capacitor is this?

I'm almost sure this is a ceramic capacitor, but I have trouble finding its characteristics. The first picture is the top side, the second the bottom side. The first shows: 120G (or 12OG) and an F. ...
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52 views

Faulty Voltage regulator?

Cant identify what is this ...SMD The only thing i can understand is that is Motorola. Any help appreciated.
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1answer
844 views

SMD diode part number from marking code [duplicate]

I can't find SMD diode part no from Marking code,pls suggest if possible.
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3answers
2k views

Voltage rating for SMD Resistor

Is it safe to use the 330K, 1206 pack as shown or to use 2x of 115k,1206 resistors in series? Input is 230v AC.
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2answers
203 views

Are IOT wireless network protocol right for high throughput point to point communication?

I am trying to build a "professional" 2 way point to point radio system (like this) to control a RC 1/10 scale car (like this ) using UART, the challenge I am currently facing is finding the right ...
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4answers
1k views

Keeping SMD parts in place while soldering with paste and heat

I was very happy to learn that I could solder SMD parts in place, by dabbing dots of solder paste on all the pads, placing my parts, and heating. I've done it using a modified toaster oven, or ...
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4answers
488 views

How many times can an IC be desoldered and resoldered?

For a long time now, I had a fear, that when you solder a SMD IC to a PCB, that you won't be able to desolder and resolder it again without destroying it. Recently, I did just that, but it didnt ...
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2answers
133 views

Surface Mount package standards guide?

Is there a universal guide-line for the mechanical dimensions and tolerances of Surface Mount packages across the industry? I'm very new to SMT machine programming (<1 year), so I've been trying ...
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2answers
356 views

Is it OK to put traces under castellated PCB

If we would speak in general: what is the strength of the solder mask in terms of breaking voltage? So if we put one PCB with castellated pads on another board like this: What will heppen if both ...
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3answers
140 views

SMD solder failure due to probing? How to solve it?

I was visually inspecting a board that had functional problems, and I have noticed a strange pattern in the pads surrounding the IC. Upon electrical inspection, there are two pads that are shorted ...
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3answers
3k views

Anyone either read japanese or know about laying tracks for a micro SD card slot?

I'm trying to include a micro SD card slot in a project I'm working on and I'm having a little trouble with the datasheet. Unfortunately I don't read japanese. Just wondering what the text says in ...
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1answer
59 views

SMD-Potentiometer question about Datasheet

I am a bit confused about this Potentiometer-Datasheet. http://www.bourns.com/docs/Product-Datasheets/PVG3.pdf Am I right, that the resistance-range is only +-20% of the resistor value? For example,...
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5answers
2k views

SMD IC mounted upside-down inside a drill hole for extreme low-profile requirements

I don't know if the title is descriptive enough, but I came across this PCB and could stop to wonder about its brilliant design. It is an aftermarket trigger controller for an airsoft gun that works ...
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1answer
215 views

Can anyone please help me identify this component, SMD (R40 515 Z5J)?

Can anyone please help me identify this component. It's marked R40 515 Z5J Dimensions are roughly 6.5mm x 6.5mm x 3.0mm my verniers have disappeared but it's pretty close.
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4answers
974 views

Can a surface-mount ceramic capacitor fail partially and intermittently?

My focus is on surface-mount ceramic capacitors. The obvious failure extremes are open and short. Other than these extremes, can the failure be that the effective value of the capacitor is either ...
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1answer
152 views

Can you identify these two SMD components? [closed]

A couple of components get knocked off by some loose elements during the shipping of some equipment. I'd like to identify the elements and solder in some replacement. My guesses: left one is a 270uF ...
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3answers
191 views

How to fix incorrect routing to SMD transistor terminals

I've got a doozy of a situation: On this circuit I had made, I routed an IRL530N D2Pak transistor with Source and Gate switched....the large heat pad should be the gate input, but instead I routed it ...
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4answers
6k views

Identifying an unmarked SMD capacitor and chip

So I'm setting myself into SMD components, as I want to create my own compact 5v step down converter, based on this component. I've read that these small brown ceramic capacitors are most likely ...
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1answer
165 views

How to Solder TQFN packages that are on both sides of the PCB

Due to a careless selection of components (and you could say also bad layout) I ended up having a PCB with surface mount pads on both sides and on the same x,y coordinates. I have already used my ...
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3answers
8k views

Difference between 1206, 0805 and 0603 SMD resistor

What is the difference between a 1206, 0805 and a 0603 SMD resistor, as far I know they all have a resistance of 10.7K? I going to need one for my little 5v DC buck converter.
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2answers
288 views

Datasheet / footprint for this weird USB-C connector?

I've got this SMD USB-C type connector I want to use: It has a single row of 12 pins along the back, presumably meaning the other 12 USB C pins are pre-connected internally. Neat. This also suggests ...
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0answers
182 views

Self Resonant Frequency VS Package Size for capacitor

In general belief, smaller capacitors have better charactristic(more capacitive behaviour) in high frequency than bulky capacitors. On contrary in one of my RF project (8.5GHz - 9.5GHz) when checking ...
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2answers
246 views

Accidental solder in vias

I am doing some assembly on a PCB which has a variety of SMD components. I accidentally got a little crazy with some paste on a large GND pad for an ESP32 component. I went to place the component on ...
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2answers
2k views

How do surface mount components withstand heat of reflow while through hole components can not?

I have read some online tutorials about soldering through hole components which say that transistors and ICs are delicate components and can be easily damaged by heat. So they recommend to keep the ...
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3answers
681 views

choosing the right fuse for a PCB

I am experimenting with making a PCB and have created some short circuits when wiring everything up which have fried one of the traces. i was wondering whether it would be a good idea to put a fuse in ...
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1answer
896 views

How to decode the markings on an SMD choke?

I have a broken Ravensburger Tiptoi pen for kids. I opened it and the choke L7 broke. It is SMD and marked 420. I found out that this could be either 42 micro or nano Henries. Question is, which is it,...
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2answers
245 views

How to mount component perpendiculary to PCB

I'm designing small PCB(20mm*20mm) where I'm also limited by height of whole project that can't exceed 20mm. I have to place few sensors on the edge of the PCB but not facing up but facing out of the ...
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1answer
201 views

MMBT2222 (SMD) transistor over 2N2222 (Non SMD) transistor

I am using a 2N2222 transistor circuit to drive 2 Relays which are parallel to each other. Can I use MMBT2222 (SMD) transistor instead of 2N2222 (Non SMD) transistor? What will be the disadvantages?
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1answer
165 views

RF limiter for -20dbm

I am working on a receiver in which I would like to limit the RF power at input to -10dBm to -20dBm, the receiver is working for frequency 1GHz. I Have checked pin diode limiters and shottkey diode ...
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2answers
216 views

SMD SOT89 identification

I am trying to Identify this SMD component, Pin 1 GND , 2-VCC, 3-? Out I can identify top letter is C , Bottom is G11, I think it might be a transistor but it odd being connected to the main power ...
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237 views

Can't identify HT74 Texas Instruments smd chip

I'm trying to find a replacement for this burned out chip, but I'm bit confused which one do I need. Thisi how it looks like: According to this datasheet, there are several HT74 chips in SSOP and ...
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1answer
128 views

How to buy electronic components for little projects? [closed]

I have some projects in mind, some of them under development, and I want to design PCBs for them with little SMD components. So I have been choosing some of the ones I need in websites like Digikey or ...
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1answer
386 views

Help me identify an SMD diode?

I think it is a Zener diode but there is no marking except a '5' and five parallel lines (polarity?). The component is on a Dumbo2 Rev2.1 motherboard for the Ideapad Z710.
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1answer
2k views

SMD Ceramic capacitor MLCC 0805 vs 0603

I'm trying to choose the right size of smd mlcc ceramic capacitor. Two of the biggest values of my capacitors are, 4.7uF and 10uF which I first chose to be 0603 because my pcb space is very limited. ...
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3answers
2k views

Help me identify a component on a PCB

What's the white component? The one besides the green resistor. It has 5 pins, the pictures are below. Here is the circuit.
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1answer
526 views

smd orientation for pick and place

I am trying to confirm the right orientation for all the packages I am using in Eagle before sending for pick and place assembly. After reading a bit, I understand that there is no standard from one ...
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1answer
92 views

SA605 input impedance

I am trying to find the associated input impedance to the SA605 mixer RF inputs. I have found several App notes associated with the Chip that discusses the design. On the datasheet they present the ...
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2answers
57 views

could I just add a microcontroller or timer to this transmitter circuit to turn it on and off so that it lasts longer?

I am thinking of making my own UHF tracking transmitters for a wildlife study. Could I just connect a low power microcontroller to the Vcc part of this circuit http://www.instructables.com/id/Tiny-...
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2answers
212 views

02B k SMD part misbehaving

First, I would like to identify an SMD part in this image, having 02B k printed on it. Where can I find some documentation? I think it should work as some kind of AND gate. There are three of them on ...
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1answer
171 views

Choosing an SMD JFET [closed]

I've prototyped a simple circuit for interfacing a ceramic mic to an iPad. It uses a 2N5457 JFET. I just happened to have that component on hand and it worked well. I'd like to implement this ...
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3answers
301 views

How to compare footprints of SMD? [closed]

How easy compare dimensions and footprints for different size SMT components. I mean how compare footprints of 0603 with 0402 size components. For example. I want to know is there possible to use ...
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2answers
32 views

remote assessment of an SMD slide switch

I am designing a PCB with one of these switches. However i have not received them yet and so i cant test which pins are connected to which when the switch is on and off.there is a little mechanical ...
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1answer
115 views

What kind of capacitors are these small, cube-shaped surface-mount components?

Complete newbie question... I'm troubleshooting a PCB that includes 4x very small cube-shaped components, labeled C2, C3, ...
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0answers
275 views

Different balun configurations

I am looking for a balun to be used as a single-ended to differential converter, 1:2 impedance ratio, including range 1.5-2.5GHz, SMT and phase balance as good as possible (and return loss). Center ...
3
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3answers
1k views

What is “folded SMA” package of SMD?

There are three types of package in specification: SMA, Folded SMA and Clip SMA. The link for datasheet: SK32A What is the differences between them ??? I suspect, that Folded SMA it is SMAF, but I ...
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2answers
839 views

Advantages of SOT Packages

after having googled I would like to Post this question here because I couldn't find reasonable answer. I have noticed at my University that hardware developers are mostly tending to use SOT Packages....
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3answers
726 views

Decoupling capacitors for 7400 type chips

I am currently designing a circuit involving several 7400 TTL series ICs that include SSI ans MSI chips, so I may need to include several decoupling capacitors for the circuit design. Documentation ...