What is TSSOP package? TSSOP package means Thin-Shrink Small Outline Package A TSSOP (Thin-Shrink Small Outline Package) is a four-sided, rectangular, thin body size surface mount component. A Type I TSSOP has leads protruding from the width portion of the package. A Type II TSSOP has the leads protruding from the length portion of the package. A TSSOP's lead count can range from 8 to 64. TSSOP package image.