SOT-323 Component Package

Overview

SOT-323 (Small-Outline Transistor 323) is a small family of SMD component packages.

Just like the SOT-23, there are 3, 5, 6, and 8 lead variants in the SOT-323 package family:

• SOT-323-3 (3 lead)
• SOT-323-5 (5 lead)
• SOT-323-6 (6 lead)
• SOT-323-8 (8 lead)

All of the variants on the SOT-323 family have a typical body width of 1.25mm and a body length of 2.0mm^{1 2 3}. The width including the leads is 2.1mm. All variants except the SOT-323-8 have a pitch of 0.65mm. The SOT-323-8 has a pitch of 0.5mm (this is needed to fit all the pins on the side of the body without changing the body length). Again, this is similar behaviour to the SOT-23 package family.

If the pin number isn’t specified, it is likely to be the 3 pin variant (this is the most common). The SOT-323 package has a significantly smaller PCB footprint than the SOT-23.

SOT-323-3

SOT-323-3 is the 3 lead variant in the SOT-223 family. This package is also commonly known by it’s EIAJ name SC-70. It is commonly used for discrete semiconductors such as diodes, transistors, and voltage regulators.

Synonyms

• SC-70: EIAJ¹.
• SCx: Analog Devices.
• SMini3-G1-B: Panasonic.
• SOT-323: If the pin number isn’t specified, it is likely to be the 3 pin variant (this is the most common).
• SOT-323-3.

Dimensions

Recommend Land Pattern

The occupied PCB area of the SOT-323-3 is \( 6.23mm^2\ (2.65mm \times 2.35mm) \) when included with the recommended reflow PCB footprint above.

Thermal Resistance

• \( T_{ja} = 380°C/W \) (mounted on 10x8x0.6mm FR4, still air)
• \( T_{jc} = 60°C/W \)

SOT-323-5

SOT-323-5 is the 5 lead variant in the SOT-323 family.

Synonyms

• SC-70-5: EIAJ.
• SOT-323-5.

Dimensions and Land Pattern

SOT-323-6

SOT-323-6 is the 6 lead variant in the SOT-323 family.

Synonyms

• SC-70-6: EIAJ.
• SC6: Analog Devices².
• SOT-323-6.

Dimensions and Land Pattern

Below are the dimensions and recommended land pattern for the SOT-323-6 package (SC6, SC70-6) from Analog Devices:

SOT-323-8

SOT-323-8 is the 8 lead variant in the SOT-323 family. It differs from both the SOT-323-3 and SOT-323-5 in that it has a pitch of 0.5mm rather than 0.65mm³.

Synonyms

Synonyms for the SOT-323-8 include:

• MO-203BA: Uncommon JEDEC name³.
• SC8: Analog Devices’ name³.

Dimensions

Below are the package dimensions for the SOT-323-8 package from Analog Devices:

Similar To

The SOT-323 family is similar to:

• SOT-23
• SOT-363

References