COMPONENT PACKAGES

TO-92 (TO-226) Component Package

Article by:

Date Published:	April 7, 2015
Last Modified:	April 7, 2015

Overview

Name	TO-92 (Transistor Outline 92)
Synonyms	TO-226 Z Package (Analog Devices) 29-11 (On Semiconductor)
Variants	TO-92 (TO-226AA) TO-92/18 (TO-226AB, TO-92MOD)
Similar To	TO-226
Mounting	TH
Pin Count	3
Pitch	Variable, commonly adjusted to 2.54mm.
Solderability	Perfect for hand soldering and prototyping! Fits well into breadboards.
Thermal Resistance	\(220^{\circ}{\rm C}/W\) (package only) \(175^{\circ}{\rm C}/W\) (plated through-holes) \(145^{\circ}{\rm C}/W\) (plated through-holes and \(0.25inch^2\) pad per lead)
Land Area	n/a
Height	10mm (typical, including body and enough space to get the through-hole legs mounted in the PCB).
3D Models	n/a
Common Uses	BJTs MOSFETs Linear regulators Active linear analogue temperature sensors Digital 1-wire temperature sensors

Usage

TO-92 is a very common package for low-power through-hole transistors, MOSFETs, and linear regulators.

Variants

TO-92

If a package is just labelled as TO-92, then it is most likely to be the “standard” variant, which is also known as TO-226AA.

TO-92/18

The TO-92/18 variant of the TO-92 package is similar to the standard package (which is just called the TO-92), except that it has a longer body. It is also known as the TO-226AB or TO-92MOD package.

Pin Numbering

Pin numbering is always done from left-to-right, when the flat side of the TO-92 package is facing you and the legs are pointing downwards, as shown in the following diagram:

This is applicable to both the standard TO-92 (TO-226AA) and TO-92/18 (TO-226AB) variants.

Standard Pinouts

The pinout for JEDEC-named 2N series transistors is standardised as per the following table:

Pin Number	BJT Connection
1	Emitter (E)
2	Base (B)
3	Collector (C)

Thermal Resistance And Heatsinks

There are a limited range of heatsinks available for the TO-92 component package. Aavid Thermalloy makes two TO-92 heatsinks, one of which is currently available (as of May 2016) on DigiKey.