In SX Microcontrollers, SX/B Compiler and SX-Key Tool, g_daubach wrote:

Hi all,

here it is - another SX48 carrier board. I have presented this design in one of the other threads before, but it took me a while to finally get my design manufactured.

This carrier board does only come with the SX48 and two 100nF filter caps between Vdd and Vss and no other components, like a resonator, an EEPROM, the SX-Key header pins etc. I have designed this board to be able using an SX48 together with a plated-through "main board" with a standard DIL-48 Socket for the SX48DIP, so all support components, like the resonator, the SX-Key header pins, etc. are supposed to be located on the "main board".

In order to minimize EMI, the carrier board has ground planes whereever possible on both sides, two filter caps, and to minimize the length of the OSC1 and OCS2 traces, I have changed pin assignments, i.e. the pin numbers on the carrier board do not match the original SX48 pins.

The attached picture shows the "plain" SX48DIP board at the bottom. In the middle, there is an SX48DIP board with small header pins (0.45mm diameter) installed that can be inserted into a standard DIL48 socket. At the top, I have placed a board with standard header pins (0.65 by 0.65 mm) that would fit into two rows of standard 24-pole header sockets.

Although I have cut off the header pins extending out of the board on the solder side for this picture, it may be an idea to keep them during the prototype phase as they nicely allow you to clip on test probes.

As all original SX48 pins are made available on the SX48DIP board, there are four Vss and four Vdd pins. For minimizing EMI, I recommend that all supply pins are connected to the Vdd and Vss potentials on the "main board" (although they are already tied together on the carrier board), and that additional filter caps are also placed on the "main board", close to the four pairs of Vdd and Vss pins.

As you may guess from the picture, I did not hand-solder the SX48 and the caps. Instead, I had a professional manufacturer with and automated pick-place-and-solder facility do the job.

Based upon the initial number of boards I have on hand right now, a single SX48DIP board (with the SX48 and the two filter caps, but without header pins) would cost US$ 19.00 including shipping from Germany. In case, there is a greater demand from the US, I can arrange shipping the boards through my daughter in the future at a reduced price. Since last week (after her marriage), she is now a permanent US resident in Georgetown, SC.

---------- End of Message ----------


You can view the post on-line at:
http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=187804

Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com

The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2007 (http://www.dotNetBB.com)