Many manufacturers use an extra letter
as their own identification code.
If the device is from Philips it will sometimes have a lower
case 'p' (or sometimes 't') added to the code;
Siemens devices usually have a lower case 's'.
For example, if the code is1A,
according to the table there are a number of possibilities:
- 1A BC846A Phi ITT N BC546A
- 1A FMMT3904 Zet N 2N3904
- 1A MMBT3904 Mot N 2N3904
- 1A IRLML2402 IR F n-ch mosfet 20V 0.9A
This has been a problem in the
past, however recently manufacturers have been adding lower
case letters which clarify the code.
Many recent Motorola devices have a small superscript letter
after the device code, such asSAC.
(This smaller letter is merely a month of manufacture code.)
Many devices from Rohm Semiconductors which start withGhave direct equivalents found in the rest of the number.
For exampleGD1is the same asD1which is a
BCW31.
Some devices have a single coloured letter (usually on extremely
small diode packages). Colour, if significant, is shown in
small type after the code letter.
An 'L' suffix
usually indicates a low-profile package, such as an
SOT323 or SC70. |
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Reverse joggle devices do present a few problems. They oftern
have an 'R' in the type number.
A reverse package is one where the lead have been bent up
instead of down. So it's a mirror image of a conventional
device.
Identification is usually possible from the code number, but
some manufacturers use the same code. In these cases, it's
a case of looking at the device with a magnifying glass.
The leads of most normal packages come out closer to the circuit
board side of the device; conversely a reverse joggle package
will have them coming out closer to the 'top' of the device.
Sometimes a series of devices, derived from the same die,
have related type (not code) numbers.
Often an 'R' will indicate a reverse joggle package,
and/or a 'W' indicate a smaller package variant, such
as SOT343.
Sometimes similarities are also found in the code numbers.
For example:
Recently some manufacturers have used a symbol or lower case
letter to indicate the country of manufacture. These have
been ignored in the alphabetical ordering. For example:
- '67' is the code for
a BFP67 (SOT143 package) ,
- '67R' is the code for
the reverse joggle variant BFP67R (SOT143R),
- 'W67' is the code for
a SOT343 package version.
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'Z-S'and'ZtS' are both 2PC4081Q devices
made by Philips; the first made in Hong Kong and the second
in Malaysia; this appears in the codebook classified underZS. |