Is This Circuit 100% matchesThis Pcb Layout

Discussion in 'General Electronics Chat' started by viri, Jun 23, 2012.

  1. viri

    Thread Starter New Member

    Jun 23, 2012
    hello dear friends
    i wanna know if my PCB layout designed correctly
    this is the PCB layout {i rendered it with component view to make it easy to check}
    and this is original circuit
    thanks for helping
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    No your pcb is wrong, you have not put in the 2.2R resistor from the juction of the 470uF cap/220R resistor.
  3. kubeek

    AAC Fanatic!

    Sep 20, 2005
    The same goes for the 100nF-1R combination. There is like 9 connections and about the same number of components, is it really that hard to compare it yourself?
  4. Markd77

    Senior Member

    Sep 7, 2009
    It's missing a 1 ohm resistor too. V- input (ground) only needs one pad I think.
    The way to check is to look at each component in turn and check all pins to see if they are connected to the correct components. Tick them off as you go along.
  5. crutschow


    Mar 14, 2008
    When I compare a circuit schematic with the layout I use a highlighter pen to mark off each trace checked on each drawing. That way it becomes readily apparent if there are any differences.
  6. WBahn


    Mar 31, 2012
    Have you made any effort to check this yourself, or do you see this forum as a free LVS service?

    First thing you should do is a component count. Do you have the same number of components on the PCB as you have in the schematic? No? Don't go any further. Identify which components are missing.
  7. steveb

    Senior Member

    Jul 3, 2008
    You'll also want to consider the current levels on the power amplifier chip. Don't know your specs, but the current levels may be over 3 Amps. Some traces may need to be thicker for power input and drive output.

    I don't know why so many people choose to etch away nearly all the copper and leave these tiny thin traces that not only can't handle the current, but are also mechanically weak, especially if you are etching your own board. Why not make very thick traces and etch away relatively little copper? You'll handle the high currents, reduce noise and voltage drops (both inductive and resistive), and the traces are mechanically stronger and less likely to lift up with stresses.
  8. WBahn


    Mar 31, 2012
    I don't know that it's a case of so many people choosing to etch away all the copper as it's a case of dealing with first things first. I've got lots of comments regarding the qualitative layout, but wanted to first get a board that actually had all the components on it.
  9. steveb

    Senior Member

    Jul 3, 2008
    I just mean that it's a common problem I see. Certainly not the only problem in this case, but an important one in this case. I'm not trying to address all issues or suggest that my comment overrides the other good comments above. However, at some point in his process, once the other issues are addressed, he will have to deal with proper trace thickness for the current requirements, and a quick look at the current levels for the TDA2003, as well as the example board layout shown in the datasheet indicate there is a big problem with his layout, in this regard.