Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Adding Bluetooth and AC-DC converter with TDA7498 Audio IC

learning

Member
1. I would like to build a PCB with a TDA7498 audio IC. I want to add Bluetooth and an AC-DC converter to the PCB board, so that a user can just power it up with a direct AC supply (220V) and run it instantly. by DC conversion. I attached the datasheet of TDA7498, and after checking it, please advise me.

2. Please tell me which PCB designing software I should use for it.
 

Attachments

  • tda7498.pdf
    1,007.6 KB · Views: 45

danadak

Active Member
Eagle and Kicad very popular CAD programs. Eagle a little more challenging
but does have auto router.

Bluetooth many vendors, here is one of the leaders -




Regards, Dana.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
EasyEDA is an excellent free PCB design program, better than many costing crazy amounts of money.
You can get it from a link on JLCPCB.com

However, I'd not recommend trying to use a surface mount IC such as that for your first design.

You would be far better off using conventional through hole components and either an all transistor circuit or at least IC amps that can be used with normal screw-on heatsinks.

The TDA7498 needs heatsinking to allow it to dissipate 20 watts of heat - something extremely difficult to do with such a small package, that has no screw on tab.

Plus the layout is quite critical and the tiny connections for high currents are very tricky, likely needing a multilayer PCB.
I've been professionally designing electronics for decades & it's not something I'd use by choice.


And note the PCB cannot be directly 220V in; you need an external power transformer to reduce the AC supply to an appropriate level, then you can put the rectification, smoothing and regulation on a PCB - but it's still a lot easier to keep that separate from the audio PCBs, both for convenience of layout and for separation for avoiding hum pickup from the AC in the power supply board.

[Yes it is technically possible to do everything in one board - but usually with a switched-mode PSU, which in itself is a major design task and probably a dozen or more prototype versions before you get an acceptable result - and it needs all the correct design isolation techniques to keep the high voltage and low voltage sides apart for safety etc. etc. If anyone ever got an electric shock due to a problem with your design, you could be in serious legal trouble.

And if you intend to sell to other people, it needs to meet strict legal standards and in much of the world be tested and certified by an independent specialist, if it uses 50V or more.

A simple power transformer with off-board AC switching and fusing, then low voltage to the PCB, avoids masses of problems and expensive failures].
 
Last edited:

learning

Member
EasyEDA is an excellent free PCB design program, better than many costing crazy amounts of money.
You can get it from a link on JLCPCB.com

However, I'd not recommend trying to use a surface mount IC such as that for your first design.

You would be far better off using conventional through hole components and either an all transistor circuit or at least IC amps that can be used with normal screw-on heatsinks.

The TDA7498 needs heatsinking to allow it to dissipate 20 watts of heat - something extremely difficult to do with such a small package, that has no screw on tab.

Plus the layout is quite critical and the tiny connections for high currents are very tricky, likely needing a multilayer PCB.
I've been professionally designing electronics for decades & it's not something I'd use by choice.


And note the PCB cannot be directly 220V in; you need an external power transformer to reduce the AC supply to an appropriate level, then you can put the rectification, smoothing and regulation on a PCB - but it's still a lot easier to keep that separate from the audio PCBs, both for convenience of layout and for separation for avoiding hum pickup from the AC in the power supply board.

[Yes it is technically possible to do everything in one board - but usually with a switched-mode PSU, which in itself is a major design task and probably a dozen or more prototype versions before you get an acceptable result - and it needs all the correct design isolation techniques to keep the high voltage and low voltage sides apart for safety etc. etc. If anyone ever got an electric shock due to a problem with your design, you could be in serious legal trouble.

And if you intend to sell to other people, it needs to meet strict legal standards and in much of the world be tested and certified by an independent specialist, if it uses 50V or more.

A simple power transformer with off-board AC switching and fusing, then low voltage to the PCB, avoids masses of problems and expensive failures].
Very good and honest advice!
 

Latest threads

New Articles From Microcontroller Tips

Top