TO-92 (TO-226) Component Package

Overview

Name TO-92 (Transistor Outline 92)
Synonyms
  • 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, MOSFET’s, 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.

A 3D render of the TO-92-3 component package.
A 3D render of the TO-92-3 component package.

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.

A 3D render of the TO-92/18 (TO-226AB) component package.
A 3D render of the TO-92/18 (TO-226AB) component 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:

A 3D render of the TO-92 component package with pin numbering.
A 3D render of the TO-92 component package with pin numbering.

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.

The TO-92 clip-on heatsink by Aavid Thermalloy (part num. 575200B00000G).
The TO-92 clip-on heatsink by Aavid Thermalloy (part num. 575200B00000G).

 

Posted: April 7th, 2015 at 1:19 pm
Last Updated on: April 12th, 2016 at 3:35 pm