Both experience with oscillating regs and simply datasheet reading.
It helps to do something normal (but wrong in the eyes of very exact people): simplify. Classic regs: no ceramic. Recent (u)LDO regs: possibly/often ceramic. All regs: electrolytic and tantalum usually work OK. Check out after choice for which regulator how to decouple exactly. Despite possibly less optimal numbers decoupling with electrolytic/tantalum caps practically never leads to issues (safe choice).
Don’t know the impact in this circuit but with SPDIF receiver ICs it does make a difference when having ultra clean PLL supply voltage. When the better regs are also cheaper it is a nobrainer. “Better” does not hurt.
You know what? You design with best choice SMD. I solder one board for you if you do have trouble soldering. Same week return. Simple 😉
It helps to do something normal (but wrong in the eyes of very exact people): simplify. Classic regs: no ceramic. Recent (u)LDO regs: possibly/often ceramic. All regs: electrolytic and tantalum usually work OK. Check out after choice for which regulator how to decouple exactly. Despite possibly less optimal numbers decoupling with electrolytic/tantalum caps practically never leads to issues (safe choice).
Don’t know the impact in this circuit but with SPDIF receiver ICs it does make a difference when having ultra clean PLL supply voltage. When the better regs are also cheaper it is a nobrainer. “Better” does not hurt.
You know what? You design with best choice SMD. I solder one board for you if you do have trouble soldering. Same week return. Simple 😉
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Ok, understand.
I will give update.
Michael
Unfortunetly i have to decline, this is DIY, not done by the others and stay supid. I am thankful that you and the other experienced pro's here, take time to explain me something and pushing me in the right direction.
I will give update.
Michael
Soldering SOT23-5 is faster and easier than SOT223 (1117).
MSOP10/WSON1 (like TPS7A39) is also easy and fast, but required hot air gun.
X2SON and other "BGA-like" are not so easy, but fortunately are usually not required for DIY.
In general, to build smt board with user friendly components (R,C >= 0603, no BGA, etc) is better end faster than through hole board.
Alex.
Make that 0805 for a first SMD project. I think OP will experience soldering SOT223 to be easier than SOT23-5. One should not want too much at once, just learn step by step.
I need to replace only one (1) 0402 resistor in a device and that is just terribly tiny. Well soldering anything smaller than 1 mm is as one can not hold that with tools at the right place anymore.
I need to replace only one (1) 0402 resistor in a device and that is just terribly tiny. Well soldering anything smaller than 1 mm is as one can not hold that with tools at the right place anymore.
I agree - 0805 is the most versatile.
Also, if to solder manually, it is possible to put 0603 and 1206 on the 0805 footprint.
For me too.
Although I have a microscope and a good soldering station.
But 0402, 0201 often just "fly away" when you hold them with tweezers....
Alex.
I have just 3 cheap soldering irons available, 1 trash, 1 good for melting screw nuts in plastik and 1 good for soldering troug hole. But would like to give me a birthday present for example better soldering equipment.
The idea is, to add some footprints in the boards free space, for some soldering experiments, to find out, what is working for me. I have to order min. 5 boards and i have a use case for the boards they are not needed.
The idea is, to add some footprints in the boards free space, for some soldering experiments, to find out, what is working for me. I have to order min. 5 boards and i have a use case for the boards they are not needed.
You can solder SMD even with a Weller WTCP-S with the right tip.
If you want to test: I have a brand new Chinese station for SMD with all tips and OLED display, auto power save etc. Send me a PM if interested.
If you want to test: I have a brand new Chinese station for SMD with all tips and OLED display, auto power save etc. Send me a PM if interested.
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A colleague from china has also picked up one with hot air and iron at his last visit, we plan to check together. Thanks for your offer, maybe i will come back later to it.
Updates:
DA101C pulse transformer added
one 220nF cap at DA101C skipped
seperate LDO for the toslink inputs; i had designed with TS1117, AP1117 also possible because of same footprint, decision depends on online availability. For the decoupling capacitors, i have added 2 footprints one through hole and one smd. After another look in the TS1117 data sheet i am uncertain, they prefer MLCC capacitors, other type of cap is available as through hole version.
added a mini 75Ohm mini coax socket, at the moment i don't not have audio source with just coax spdif, everything is with toslink. But you never know, if it is necessary later on, a coax input can be easily added to the housing.
added some footprints for solder checks, at unused boards
Feel free to comment, please.
DA101C pulse transformer added
one 220nF cap at DA101C skipped
seperate LDO for the toslink inputs; i had designed with TS1117, AP1117 also possible because of same footprint, decision depends on online availability. For the decoupling capacitors, i have added 2 footprints one through hole and one smd. After another look in the TS1117 data sheet i am uncertain, they prefer MLCC capacitors, other type of cap is available as through hole version.
added a mini 75Ohm mini coax socket, at the moment i don't not have audio source with just coax spdif, everything is with toslink. But you never know, if it is necessary later on, a coax input can be easily added to the housing.
added some footprints for solder checks, at unused boards
Feel free to comment, please.
I don't like the idea with the to footprints for one cap, i had decided to use trough hole, because i have some in stock and everything available as TH.
As last change, on each voltage regulator output a led was added, to create a minimum load for the regulators and optical indicator. The assembly is optional, just planned in.
If there are no further hints and critics, i would like to go with this version.
As last change, on each voltage regulator output a led was added, to create a minimum load for the regulators and optical indicator. The assembly is optional, just planned in.
If there are no further hints and critics, i would like to go with this version.
There is always a load isn’t it?
Still think the coax connector should be either RCA or BNC in the same direction as the others. This is such a design choice regretted when a (normally superior) coax interface device will be connected. The way it is done now will require an ugly extension cable. PCB mount BNC have the benefit of having a large nut to mount the complete PCB to the plastic casing.
I solve the SMD/TH cap choice by having footprints for both. Costs nothing.
The 45 degree corners of the thin PCB tracks come too close to other pins without a valid reason. They also not go in the middle of for instance L7 pins. Ugly. Solved by adding more corners.
Having both large TH resistors because you have them AND SMD resistors is weder Fleisch noch Fisch 😉 and also frowned upon by yourself later on. As an example: 0805 10 kOhm and 0805 22 Ohm at the left make the board smaller and/or connections are shorter. When also done at the coax section the PCB can be smaller with same functionality. Smaller usually means more easy to mount in a device/casing.
Still think the coax connector should be either RCA or BNC in the same direction as the others. This is such a design choice regretted when a (normally superior) coax interface device will be connected. The way it is done now will require an ugly extension cable. PCB mount BNC have the benefit of having a large nut to mount the complete PCB to the plastic casing.
I solve the SMD/TH cap choice by having footprints for both. Costs nothing.
The 45 degree corners of the thin PCB tracks come too close to other pins without a valid reason. They also not go in the middle of for instance L7 pins. Ugly. Solved by adding more corners.
Having both large TH resistors because you have them AND SMD resistors is weder Fleisch noch Fisch 😉 and also frowned upon by yourself later on. As an example: 0805 10 kOhm and 0805 22 Ohm at the left make the board smaller and/or connections are shorter. When also done at the coax section the PCB can be smaller with same functionality. Smaller usually means more easy to mount in a device/casing.
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Not sure, how much load it has without input signal. The AP1117 data sheet includes a minimum load row. Is optional, as you said costs nothing, if not needed.
I is there an advantage from electrical point of view, mounting the RCA/BNC connector to the board. I would like to prefer the more flexibility in mounting the connectors. Housing is an open decision, regarding size, material and so on.
Yes, was always planned as XOR solution.
😳
Good point with the 0805 resistors, at the moment soldering the ST485 is the challenge for me. IMO this would at more challenges form me. Nevertheless i have to improve my solder skills in the future, because the board with Teensy has to be SMD and size will matter.
Michael.
Shorter connections are better. No cabling is always better too. Unless you are of the modular design faith group, design for least possible wiring/cabling. Does not hurt the eyes and the wallet either. Simpler is better and more reliable. Modular is a curse invented by programmers and cable manufacturers 🙂 A Komplott! Not many reuse modules for a new design (a reason often cited) as new ideas overrule the old. It is BS, just make esthetic pleasing short connections no excess wiring well performing stuff.
Don't prepare for the future, prepare for the now. The present (SMD as it was and as it is now) is already hard enough. The future is no manual soldering anymore!
ST485 will work out just fine with the famous solder wick trick. You might as well have the other IC too in SOIC. SOIC are easy to solder, you will notice. Don't fear the unknown, embrace it.
Going out now, my Drufi started to leak and needs a new Flanschdichtung. Water is not my comfort zone but I manage just like you will manage SMD soldering.
Don't prepare for the future, prepare for the now. The present (SMD as it was and as it is now) is already hard enough. The future is no manual soldering anymore!
ST485 will work out just fine with the famous solder wick trick. You might as well have the other IC too in SOIC. SOIC are easy to solder, you will notice. Don't fear the unknown, embrace it.
Going out now, my Drufi started to leak and needs a new Flanschdichtung. Water is not my comfort zone but I manage just like you will manage SMD soldering.
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A DC blocking capacitor and its discharging resistor could be put in at the input side of the transformer, they are good to have just in rare case of hostile potentials presence.
Good thinking but how often does that happen? Chances are that the device has either a cap or a transformer itself. This was concluded after years of implementing the cap and checking the sources 😉
I follow the advise of a coaxial connector. And regarding the mechanics, if you have used M3 hardware, make sure you have a circle of 7mm diameter around your holes free of everything. No pads, no components, no traces, no via's. Top and bottom. then you can be sure that even if you use a bolt with a washer and a metal pillar at the bottom that it won't make contact.
So i had done the most brave decision in my live, and switched the resistors footprints to 0805 and saved 13mm of width. Hopefully the tracks looking better.
Do you have experience width in pad via? Jlc is offering via under pad, maybe i have to check this with jlcpcb.
Yes i will use M3 hardware, i had a look and it should work without any unexpected contacts. Generally i plan to keep the housing GND-free. For the power supply, 2 torodials will be used, one for analog and one for digital section. If the housing will be from metal only earth potential will be added, because of safety reasons. Generally the pcb holders coming out of a 3d printer, ESD protektion is also a point.
Do you have experience width in pad via? Jlc is offering via under pad, maybe i have to check this with jlcpcb.
What is the risk? Destruction of the Transformer, voltage breakdowns or something else. Can i use simple diode to shorten these voltages if there are to high?
Yes i will use M3 hardware, i had a look and it should work without any unexpected contacts. Generally i plan to keep the housing GND-free. For the power supply, 2 torodials will be used, one for analog and one for digital section. If the housing will be from metal only earth potential will be added, because of safety reasons. Generally the pcb holders coming out of a 3d printer, ESD protektion is also a point.