MPS2222A Transistor

Comments about RadioShack MPS2222A Transistor:

To start off, I bought this product for myself for a home improvment project. I've just been frustrated by this product.

Looking at the MPS2222A datasheet

http://www.datasheetcatalog.org/datasheet/GeneralSemiconductor/mXvurqw.pdf

Pin 1 is the emitter and Pin 3 is the collector.
The package of the radioshack transistor has the two switched.

The base-emitter voltage should be and is near 6V.
That is between pins 1 and 2.

By the way the pinouts for the msp2222a and the 2n2222a are the same, see url below:

http://www.fairchildsemi.com/ds/PN/PN2222A.pdf

Comments about RadioShack MPS2222A Transistor:

FOR SERVICE... This famous, general purpose device replaces most small-signal, NPN, silicon transistors. (For example, 2N3904 and 2N4401.) Before you make the replacement, you should check the circuit requirements against device specs. Also, the 2N2222A pinout might not match the pinout of the device that you're replacing.

FOR DEVELOPMENT... The 2N2222A is an excellent choice. Devices of recent manufacture have fairly good uniformity. The maximum current gain is usually about 200. Expect to see 200 at audio frequencies, and a declining gain into the shortwaves and VHF. The top frequency is often about 300 MHz. This is a small-signal device. Yet it can easily drive an LED, or even a 100-ohm speaker.

TYPICAL... In typical applications, the current draw ranges from 0.1 to some 50 mA. The lower current ranges permit long battery life. The typical voltage range is about 3 to 18 volts. (These current and voltage ranges are well within device maximums.) Operation requires current-limiting and voltage-bias resistors.

LIMITS... A 2N2222A won't compete with some specialized devices. For example, don't try to use a 2N2222A in a UHF circuit. And don't expect the 2N2222A to replace a low-noise device. This is an average device, and sort of a semiconductor "Swiss Army knife."

OVERALL... The 2N2222A is extremely versatile. It will work fine in most typical audio, radio, mobile, home, office and experimental applications. It's inexpensive enough so that you can buy three or four and experiment. (For non-critical experiments, consider the economy pack of 15 generic, NPN devices. If you need uniformity, though, buy 2N2222A-brand devices.)

If you design conservatively, the 2N2222A will give excellent performance and last indefinitely.

Comments about RadioShack MPS2222A Transistor:

This Transistor is great for electronic projects. I use it in my Natural VLF radio receiver experiments.