Semiconductors:
Little details you will need to know:
Finding Pin 1.
Some of the ICs used in this kit have a dot or indentation at the Pin 1 corner of
the chip. For others, the Pin 1 locations isn't as obvious. The manufactures logo
is sometimes used (as is the case for U1 and U2) or sometimes there is a line
along the Pin 1 end of the chip. In all cases, there is a beveled or rounded edge
along the side of the IC package. When the chip is viewed so the package is
orientated vertically, Pin 1 is always in the upper left corner.
Before placing an IC or transistor, tin one of the corner pads and then tack that
lead of the part down first. Before soldering any other pins, make sure all the leads are lined up on the pads.
This is especially important for U7, where these isn't much room for error. Then solder the lead on the opposite
corner from the tacked lead to make sure the body doesn't move when you solder the rest of the leads.
U4 and U5 are very similar. The way to tell them apart is the fact U4 has 5 leads and U4 has 6. U4 has a faint
dot which marks the pin 1 end, also the lettering “CC5R” will be upside down when installed correctly.
U11 is the rectangular box with the silver top. Be sure to get solder to flow into the little “U” shaped cups near
each corner of the part. A number of builders have had trouble with this and not made solder connection to the
pads under the part. A fine tipped iron is required here. Also, be careful of using too much solder and making a
short to the metal top of the package.
D1 and D4 have very faint lines printed on them to indicate the cathode end. Look carefully for these line and
face them towards the line printed on the board.
The two regulators and the TO-23 sized transistors and IC carriers have been color coded with a sticker and
corresponds to the color on the layout diagram. Simply match colors like with the caps.
There maybe more numbers or letters on the semiconductor packages then indicated on the layout diagram.
These are date or lot codes and can vary depending on when the parts are purchased. Therefore these are not
used for part identification on the layout diagrams.
FRONT SIDE
U1, U2: SA612A
U3: LM4808
U4: CC5R Note dot showing orientation.
U5: AC
U6: M430F1232
U7: AD9834
U8: AC02
U9: Orange sticker, C3E
U10: Green sticker, C2P
Q2,Q3: Pink sticker, 12W or 702
D4: W8, small black rectangle Note polarity!
U11: 60 MHz clock osc. This is the silver can. Getting solder to flow under the pad can be tricky, be sure to put
the iron up to the little cup on the side of the pad. Be careful not to short to the metal top of the package.
(Note the U11 designation is duplicated on the front of the board for the uP rest chip)
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