SSOP Package — Introduction & Applications

SSOP (Shrink Small Outline Package) is a surface-mount    integrated circuit package with gull-wing leads extending from two opposite    sides of a rectangular plastic body. It is a “shrunk” version of the standard    SOIC package, featuring a finer lead pitch and a smaller body footprint.

SSOP packages are widely used for medium-pin-count analog, digital,    mixed-signal, and interface ICs. They offer a practical balance between    compact size, manufacturability, solder-joint inspectability, and cost.    Typical lead pitch is 0.65 mm, with pin counts commonly    ranging from 8 to 56 pins.

Key Features and Advantages

  • Compact surface-mount package: Smaller than SOIC for the same pin count.
  • Fine lead pitch: Typically 0.65 mm for higher pin density.
  • Gull-wing leads: Provide mechanical compliance during thermal cycling.
  • Optically inspectable solder joints: Unlike BGA or QFN.
  • Mature assembly process: Compatible with standard SMT reflow soldering.
  • Wide availability: Many analog, interface, logic, and memory ICs.
  • Cost-effective: Lower routing and inspection cost than BGA for medium I/O density.

Typical Specifications

ParameterTypical Value
Package TypeShrink Small Outline Package (SMT)
Lead Pitch0.65 mm (some 0.8 mm variants)
Pin Count8 to 56+ pins
Body Width3.9 mm, 5.3 mm, 7.5 mm
Body Thickness~1.75 mm to 2.0 mm
Lead StyleGull-wing, two sides
MountingSurface-mount (SMT), reflow soldering
Operating Temperature−40°C to +85°C or +125°C (device dependent)

Common SSOP Variants

VariantDescriptionTypical Applications
SSOP-88-pin, 0.65 mm pitchOp-amps, comparators, EEPROM, interface ICs
SSOP-1616-pin, 0.65 mm pitchLogic, multiplexers, ADC/DAC, drivers
SSOP-20/2420–24 pinsInterface ICs, memory, controllers
SSOP-28/3228–32 pinsMicrocontrollers, data converters, communication ICs
SSOP-48/5648–56 pinsBus interfaces, logic, memory, display drivers
TSSOPThinner version, ~1.0 mm heightPortable electronics, space-constrained designs
QSOPQuarter-size, 0.635 mm pitchCompact analog and mixed-signal circuits

Major Application Areas

Analog and Mixed-Signal ICs

Operational amplifiers, comparators, data converters (ADC/DAC),    multiplexers, analog switches, and sensor signal-conditioning ICs.

Interface and Communication ICs

RS-232, RS-485, CAN, USB, UART, and other interface transceivers for    industrial communication, networking, embedded systems, and peripherals.

Logic and Memory Devices

Logic gates, shift registers, bus transceivers, decoders, EEPROM, Flash    memory, and SRAM for control systems, data storage, and embedded designs.

Microcontrollers and Embedded Systems

8-bit, 16-bit, and 32-bit microcontrollers for consumer electronics,    industrial control, automotive modules, and IoT devices.

Consumer Electronics

Smartphones, tablets, set-top boxes, televisions, audio equipment,    wearables, and portable media players.

Industrial Control and Automation

PLCs, motor drives, sensor interfaces, data acquisition, instrumentation,    and process control equipment.

Automotive Electronics

Body control modules, infotainment systems, sensor interfaces, power    management, and legacy ECU designs. AEC-Q100 qualified versions available.

Medical Devices

Patient monitoring, diagnostic instruments, portable medical devices, and    medical imaging equipment.

Computing, Networking, and Data Storage

Motherboards, network routers, switches, optical modules, SSDs, and embedded    computing boards.

Advantages and Disadvantages

Advantages:

  • Smaller than SOIC for the same pin count.
  • Solder joints are optically inspectable.
  • Mature, low-cost SMT assembly.
  • Wide availability across analog, digital, and mixed-signal devices.
  • Good mechanical compliance from gull-wing leads.

Disadvantages:

  • Larger footprint than QFN or BGA for equivalent pin count.
  • Fine 0.65 mm pitch requires careful PCB routing and stencil design.
  • Higher parasitic inductance than leadless packages.
  • Moderate thermal performance compared with QFN with exposed pad.
  • Not ideal for very high pin counts or extreme miniaturization.

SSOP vs. Related Packages

PackageLead PitchBody ThicknessMountingTypical Pin CountNotes
SOIC1.27 mm~1.75 mmSMT8–28Larger, easier soldering
SSOP0.65 mm~1.75–2.0 mmSMT8–56+Smaller than SOIC
TSSOP0.65 mm~1.0–1.2 mmSMT8–64+Thinner, portable electronics
QSOP0.635 mm~1.75 mmSMT16–40Quarter-size, compact
QFN0.4–0.5 mm0.8–1.0 mmSMT16–100+Leadless, thermally enhanced

Selection Considerations

  • Pin Count: 8–56+ pins based on I/O requirements.
  • Lead Pitch: 0.65 mm standard; verify PCB manufacturing capability.
  • Body Width: 3.9 mm, 5.3 mm, or 7.5 mm depending on pin count.
  • Thermal Requirements: Consider QFN or exposed-pad packages for high-power devices.
  • Temperature Grade: Commercial, industrial, or automotive (AEC-Q100).
  • PCB Design: Proper pad geometry, solder mask, and stencil design for fine-pitch leads.
  • Assembly: Reflow soldering is standard; optical inspection is possible.
  • Availability: Confirm long-term supply and second-source options.