kicad-lib-committers team mailing list archive

[Carl Poirier <carl.poirier.2@xxxxxxxxx>]

Simply sending to all, because it is of great interest, the reply from
Lorenzo which was addressed only to me:

> JEDEC is freely availably, just register.

> IPC is not, I have some of the (paid) relevant standards, but it's mostly
for the formulas and constant tables. The naming standard for IPC (both
packages and padstacks) is free, get it here:

> http://landpatterns.ipc.org/IPC-7351BNamingConvention.pdf

> However it's *so* ugly that I think nobody actually uses it except their
> calculator (made by Mentor AFAIK)

> As the fact 'is JEDEC standard': yes, *most* of the stuff out there
> follows a JEDEC standard, usually a MS (for SOIC) or MO (for
> SOT/SSOT/TSOP). Also TO are in wide use. However take care:
> while the commonly used SOT-23 is actually TO-236 (and with that I mean
> that *usually* the manufacturer package is compatible with the JEDEC
> standard), the commonly called SOT-23-5 and SOT-23-6 (the 5 and 6 pin
> version with the same body) are usually MO-193 *or* MO-178 (hint: the
> height changes is different...). Also the (JEITA, IIRC) SC packages
> often are 'compatible' with JEDEC ones: the SC-59 is for most practical
> purpose a TO-236 (yes, another name for the SOT-23 :D)

> Sadly there are exceptions: for example switchers in DPAKs (or D2PAK,
> D3PAK) have usually custom packages (like the National/TI TJ7A),
> Microchip has an 'oversize' SOIC-8 (same land pattern but wider body)
> and even out of standard TQFP (the C04-110, used for big dsPICs).

> As for the hypen issue: the official name *has* the hypen, but the part
> before is always alphabetic and the part after is always numeric so
> there is no risk of confusion. Letter after the number can be the
> variation code when talking about the package (TO-236AB, for example)
> but be careful because TO-236H means 'issue H of the TO-236 standard'.

> And, by the way, the official designator is R-PDSO-G (never seen it
> outside the drawing, of course).

> My convention for hypens is: use it between manufacturer and code, when
> it's needed for resolving ambiguities and for pinout name variations.
> So I have TO236-BEC, TYCO-RV3402, BOURNS-SDTM and so on. Otherwise no
> hypens; example R2512K is a 2512 resistor with kelvin connections.

> That works for me.

> And don't forget about the zero orientation :D (hint: ISO, JEDEC and IPC
> differs :D)


On Mon, Mar 10, 2014 at 2:44 PM, John Beard <john.j.beard@xxxxxxxxx> wrote:

> On 10/03/14 15:10, Carl Poirier wrote:
> > Let's continue our discussion about this. Lorenzo, do you have access to
> > the relevant documents?
> >
> > On Wed, Feb 26, 2014 at 2:22 PM, Vesa Solonen <vesa.solonen@xxxxxxxx
> > <mailto:vesa.solonen@xxxxxxxx>> wrote:
> >
> >26/02/14 11:00, Kerusey Karyu kirjoitti:
> >>
> >> In 25 lutego 2014 19:46 Carl Poirier wrote:
> >>
> >>> Regarding your last email, do you have any reason why not
> >>> to put a dash between "SOT" and "23", for example?
> >>>
> >
> >The most important thing to consider when deciding is JEDEC standard. It
> >seems they say with dash.
>
> Hi,
>
> I don't know if this standard is the one you are looking for, but
> JEDEC Publication Number 95, Section 1.6 "Outline Classification"
> might be along the right lines when talking about a JEDEC Outline
> Number:
>
> > 1.6 a) Outlines are designated with two letters (DO, TO, MO, UO, CO)
> > followed by sequential numbers (e.g., DO-35, TO-220, MO-16).
> >
> > 1.6 b) Two letters follow the number to designate which member of
> > the family of variation (e.g., DO-OO1AA, TO-226AB, MO-069AE). Often
> > the only differentiation between variations is the lead count.
>
> JEDEC Standard 30 (I looked at Rev. F), section 3.1 describes a
> "descriptive designation", as opposed to the outline number.
>
> >
> > 3.1 General:
> >
> > ...a mandatory field (shown below) consisting of a three-letter basic
> > package designator that indicates the package outline style and
> > terminal position or form, preceded by a field to indicate the
> > package-body material. This mandatory package designator may be
> > extended, through the use user-selected fields, to provide
> > additional package information such specific package features,
> > package differentiators, terminal count, and supplemental
> > information separated from the descriptive designator by a slash (/).
>
> An example is "TS-PDSO2-44(50)/5.3x10.2-1.27". It doesn't say
> anything about the presence or not of a hyphen between "DSO" and
> "2". However, the examples in Table C.1 of JESD30F uses "SOT89" as an
> example. This is the only descriptive designator in the table
> without a hyphen (others include T-PQFP-44).
>
> We also don't see the hyphenation used in section 3.1 in everyday
> usage of packages like TSSOPs, where TS is a "specific package
> feature" (thin shink, see table 3) and "SOP" is the "package
> designator" (table 1), rather we see a hyphen in between TS and the rest.
>
> So it seems to me that JESD30 and JEDEC PN 70 don't fully define the
> question that you're asking re hyphenation, and aren't even totally
> consistent with their own examples. Moreover, SOT may be a bad
> example to use, as it is unique in not having a hyphen in the
> examples table.
>
> Sorry to not have a cut-and-dry answer!
>
> Cheers,
>
> John
>
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