Terminology

SOP, or Small Outline Package, is a type of surface-mount package characterized by lead pins extending from two opposite sides of the package. These leads are typically in a gull-wing (L-shaped) configuration. SOP packages can be made from either plastic or ceramic materials. They are widely used for memory LSIs (Large Scale Integrations) and ASSPs (Application-Specific Standard Products) that do not have a large circuit scale. SOP is the most popular surface-mount package in applications requiring a moderate number of input/output terminals, typically ranging from 10 to 40 pins.

The orientation of the pins, whether on the shorter or longer side of the package, categorizes them into TYPE I (pins on the shorter side) and TYPE II (pins on the longer side). The standard pin pitch for SOP is 1.27mm (50 mils), and the pin count ranges from 8 to 44 pins. Additionally, SOP variants with a pin pitch less than 1.27mm are called SSOP (Shrink Small Outline Package), and those with a mounting height of less than 1.27mm are known as TSOP (Thin Small Outline Package). SOP is sometimes also referred to as FP (Flat Package).