High Power Transistor Packages

Transistor packages usually use the nomenclature TO-xx, where TO stands for Transistor Outline.  There are a number of transistor packages that will handle high power or high current, but it also depends on the semiconductor inside the packages.

A number of different transistor packages have been added over the last month, several can handle higher power loads. One package style is the TO-3 flange mount body. The TO-3 style dissipates a lot of heat because of the large metal package and because the metal flange is normally mounted to an even larger metal plate to dissipate even more heat. The most common TO-3 package holds two leads, with the case acting as the third terminal. Two additional new TO-3 related pages were added; the first a 4-lead TO-3 package, and the second an 8-lead TO-3 package.

Another through hole style high power package is the TO-220, although this one has a metal tab to dissipate heat. The 3 terminal package already resided on the site; however a 5-terminal TO-220 and a 7-Lead TO-220 package were added. The 7-leaded package has staggered leads, and there's an additional 5-Staggered Terminal TO-220 package to compliment it. Either of the new packages are designed to hold more than just a single transistor or FET; operational amplifiers in the case of the TO-3 package or regulators in the case of the TO-220 packages.

The other high power transistor case is the TO-263, or the surface mount version of the TO-220. There's a 3-terminal version, a 5-Terminal TO-263 package and a 7-Terminal TO-263 package.

It's easy to determine the number of pins required for a particular package, normally the function will dictate the number of leads. However it's a bit harder to pick the correct package style. So these are a few of the transistor package styles designed to dissipate high heat on the site.

TO-205 FET Package

A new page holding a graphic of a TO-205 Metal Can was generated. This particular page gives the pinout for an FET, with the transistor pinout to be added later. As with any of the pages, this is linked off the FET Packages page.

3-Terminal TO-247 Semiconductor Package

Yet another new semiconductor package style added today. This time the component is a 3-Terminal TO-247AC Package. The 'AC' portion of the package type defines the package style depicted on the page. There are other styles of TO-247 components with many more than 3-leads. It's my impression that the TO-247 base number defines a  package with an exposed metal plate on the rear of the component that connects directly to the semiconductor die; however I did not take the time to look that up.

The page graphic shows a package out-line and the dimensions for a TO-247AC and gives the pinout for an FET, but the text also provides the pin out for a transistor package.

As with any other similar package, any type of semiconductor could reside in the body of this case; however only a FET and BJT are given as examples. A few N-Channel FETs that use this package include; 2N7563, 2N7564, and 2N7565 [150 to 320 watts].

As with all new page additions to interfacebus, the page gets a mention in this blog, and to the external Engineering Sitemap. In addition there is always at least one internal link, in this case off the Transistor Packages page.

So every new page addition receives at least three incoming links, with two of the incoming links being external to the web site. However at last check the links on the site-map were 'no-follow', which means there is no credit for the link. The no-follow thing is Google's idea, and I have no control over that. Even if the sitemap does no really provide any search engine ranking it still works as a site-map, which is what it really is.

TO-276 Three-Terminal Surface Mount Package

What is a TO-276 device?
A 3-Terminal Surface Mount Component, shown on; TO-276 Transistor Package.
As discussed on that page the package may be used for any number of different semiconductors, but the term transistor is used in general. As with all the other related packages the TO-276 page is linked off the Transistor Packages page.

There's not much left to say, as this posts relates to the last two previous posts, which have already covered every thing.

This is the first surface mount package added to that section of the web site, all the other pages cover some type of through hole package. However I have had pending data on several other surface mount styles but the data has not been added yet because I been working other site issues ~ I'm not sure if I can add yet another package type in the next few days or not. Of course the Site-Map was also up-dated.

Transistor Die Bonding

Semiconductor Case Drawings

Added a few new pages covering transistor package styles.
This series of pages really don't generate any incoming hits, but I already had the data so why not just add the pages. Plus its been awhile with out adding any new pages.

The first covers a TO-18 Transistor package.
The second page covers a TO-92 Transistor package.
A third page covering a TO-204 Transistor.
A final page covering the TO-220 Style Package.

The graphics used on these page were already being used on some other page on the web site. So the only new thing that was added today was four new web pages, but the data was already on the site at a different page. However these new additions do round out the main package style page.

At any rate this posting shows the 3 new pages and provides an external site that links to them, I can't really help that they may never see any visitors.

Recommendation on how to Derate a Transistor

Starting with the long list of Transistor Derating Curves, I added in several transistor links to Transistor Derating Guidelines [which is the new page]. Or, recommendations on how to derate a transistor based on a linear equation, with no graphic [Derating Curve].

The new transistor links pick up missing devices in the list, but because I didn't have a derating chart they all point to the new page which provides the derating recommendation for each of the devices. The recommendation for each transistor is how much to decrease power dissipation over increasing temperature, mW/C [and that's all].

Two of the main links off the transistor derating page are NPN Derating Curves, and PNP Derating Curves, but I don't have any plans to add the new links to either of those pages.

Individual transistor pages not yet listed in the blog;
2N3250 Derating Curve.
2N3467 Derating Curve.
2N3485 Derating Curve.
2N3634 Derating Curve.
2N3740 Derating Curve.

A related list; How to derate FETs.
2N6764 Derating Curve.
2N6766 Derating Curve.
2N6768 Derating Curve.

How to Derate a Component.
Site Home page; Computer Bus pin Outs.

FET Derating Guidelines

Derating guidelines for a 2N7000 Field Effect Transistor [FET] was added; 2N2700 Derating.
Unlike the other pages within the FET Derating section, this page only offers recommendations.
All the other pages, or many of them, provide derating curves that should be considered as absolute rules rather than recommendations.
Of course a FET is a style of Transistor, which are covered on the Transistor Derating Guidelines.

The over-all section is Component Derating, if you see a table than it's a guideline, while a curve will imply a rule. The goal is to not exceed the devices junction temperature.

The 2N27002 FET is also covered on the page link.
The 2N7000 device is a plastic TO-92 package, while the 2N7002 is a SOT23 plastic package.

Of course Connector derating guidelines and Cable derating guidelines are also provided within this section, neither of which have a semiconductor junction. Their package or molding is being derated. A Thermal Couple is used to monitor the body of the package for temperature increases. There's a limit to the number of wires in a cable or pins on a connector that can carry some amount of current. Sure one pin may handle an amp of current, but if the connector or cable has 50 leads, does it imply that the component can deal with 50 amps of heat dissipation [no].

For reference;
2N6770 Maximum Case Temperature.
2N6768 Maximum Case Temperature.
2N6766 Maximum Case Temperature.
2N6764 Maximum Case Temperature.