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An outline drawing of a Type I TSOP with 32 leads

Thin small outline package (TSOP) is a type of surface mount IC package. They are 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 due to their high pin count and small volume. In some applications, they are being supplanted by ball grid array packages which can achieve even higher densities. The prime application for this technology is memory. SRAM, flash memory, FSRAM and E2PROM manufacturers find this package well suited to their end-use products. It answers the needs required by telecom, cellular, memory modules, PC cards (PCMCIA cards), wireless, netbooks and countless other product applications.

TSOP is the smallest leaded form factor for flash memory.[1]


The TSOP package was developed to fit the reduced package height available in a PCMCIA PC Card.[2]

Physical properties

TSOP48 type I: Silicon Storage Technology 39F1601
TSOP54 type 2 Winbond W982516BH75L

TSOPs are rectangular in shape and come in two varieties: Type I and Type II. Type I ICs have the pins on the shorter side and Type II have the pins on the longer side. The table below shows basic measurements for common TSOP packages. [3]

Type I

Part number Pins Body width (mm) Body length (mm) Lead pitch (mm)
TSOP28 28 8.1 11.8 0.55
TSOP28/32 28/32 8 18.4 0.5
TSOP40 40 10 18.4 0.5
TSOP48 48 1 18.4 0.5
TSOP56 56 14 18.4 0.5

Type II

Part number Pins Body width (mm) Body length (mm) Lead pitch (mm)
TSOP6 (SOT457)[4] 6 1.5 2.9 0.95
TSOP20/24/26 20/24/26 7.6 17.14 1.27
TSOP24/28 24/28 10.16 18.41 1.27
TSOP32 32 10.16 20.95 1.27
TSOP40/44 40/44 10.16 18.42 0.8
TSOP50 50 10.16 20.95 0.8
TSOP54 54 10.16 22.22 0.8
TSOP66 66 10.16 22.22 0.65


HTSOP (Heatsink TSOP) is a variant of TSOP with an exposed pad on the bottom side.[citation needed] The pad is soldered to the PCB to transfer heat from the package to the PCB.

Similar packages

There are a variety of small form-factor IC carrier available other than TSOPs

See also


  1. ^ Intel (1999). "Small Outline Package Guide" (PDF). p. 1-1. Archived from the original (PDF) on February 11, 2017. Retrieved December 17, 2021.
  2. ^ Texas Instruments. "Recent Advancements in Bus-Interface Packaging and Processing". 1997. p. 2
  3. ^ SiliconFarEast: "TSOP - Thin Small Outline Package"
  4. ^ "Sc-74; Tsop6 (Sot457)".