What is TSOP package? TSOP package means small-outline packages Thin small-outline packages, or TSOPs are a type of surface mount IC package. They are notably very low-profile (about 1mm) and have tight lead spacing (as low as 0.5mm).
They are frequently used for RAM or Flash memory ICs dues to their high pin count and small volume. However, they are being supplanted by ball grid array packages which can achieve even higher densities. TSOP package picutre.