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TO-99 Component Package

Authors:
Geoffrey Hunter
Geoffrey Hunter
Published On:
Mar 13, 2021
Last Updated:
Mar 13, 2021

The TO-99 (Transistor Outline 99) is a 8-pin can-type through-hole component package. It is an older through-hole part which has been used for ICs, especially op-amps.

A photo of the TO-99 component package. Image from https://www.amazon.com/LM741H-OPAMP-1-5MHZ-TO99-8-LM741/dp/B01CNL17NC, retrieved 2021-03-13.

The dimensions of the TO-99 package are shown below. The pins are arranged of the circumference of a 2.54mm (0.1inch) radius circle with a pin placed every 45°. A metal tab indicates pin 8.

Dimensions of the TO-99 component package. Image from https://www.analog.com/media/en/package-pcb-resources/package/pkg_pdf/headerh/h_08_1.pdf, retrieved 2021-03-13.

The popular LM741 op-amp comes in this package, the pinout is shown below:

Pinout for the LM741 op-amp in the TO-99 component package. Image from https://media.digikey.com/pdf/Data%20Sheets/Texas%20Instruments%20PDFs/LM741_Series_Rev_July_2016.pdf, retrieved 2021-03-13.