4.5mm SMD Tact Switch 4 Pin – 4.5×4.5mm Tactile Push Button

The TS-1109S is a 4.5mm SMD tact switch — a compact 4.5×4.5mm surface-mount tactile push button designed for PCB control applications where reliable momentary switching and efficient board-space utilization are required. This 4.5×4.5mm tact switch provides a crisp tactile response with a short 0.2mm travel, making it suitable for consumer electronics, IoT devices, industrial controls, and portable equipment.

This 4 pin SMD tact switch features a four-pin SMT construction that enables automated PCB assembly and stable mechanical mounting. The 4-pin configuration provides redundant electrical contacts and enhanced PCB retention compared to 2-pin alternatives, improving reliability in high-cycle applications. The switch is available in two operating force options — 180gf for lighter touch applications and 260gf for applications requiring a more deliberate actuation feel.

Manufactured in an ISO 9001:2015 certified facility, this 4 pin SMT tact switch is fully compliant with RoHS 3 and REACH regulations. Available in reel packaging for automated SMT assembly, with OEM customization options for volume orders.

Below are the complete specifications for the 4.5×4.5mm tact switch TS-1109S, covering electrical, mechanical, and environmental ratings.

Specifications should be verified against the latest product drawing and engineering documentation before production release. Electrical performance depends on the complete circuit design and load conditions.

When selecting a 4.5mm SMD tact switch for your PCB design, engineers should compare five key parameters to ensure the best fit for the application.

1. Footprint

The 4.5×4.5mm footprint offers a good balance between board space and tactile area. It is larger than 4×4mm switches but smaller than 6×6mm options, making it suitable for applications where the switch needs to be large enough for comfortable operation but small enough for compact PCB layouts.

2. Operating Force

Operating force affects user experience and reliability. 180gf provides a lighter touch for applications where users press the switch frequently. 260gf offers a more deliberate actuation feel, reducing the risk of accidental presses in industrial or high-vibration environments.

3. Travel

The 0.2mm travel provides a crisp tactile response with minimal actuation distance, suitable for applications requiring precise feedback and quick actuation.

4. Electrical Rating

Confirm that the 50mA / 12V DC rating meets your circuit requirements. For higher current or voltage applications, consider a different switch specification.

5. Operating Life

The TS-1109S is available with 50,000 or 100,000 cycle ratings depending on the force option. Choose based on the expected usage frequency and application requirements.

Need a different configuration? Explore our full tactile switch product range.

A 4-pin SMD tact switch is a momentary push button that provides a temporary electrical connection when pressed. The TS-1109S uses a SPST-NO (Single Pole, Single Throw — Normally Open) circuit configuration.

Switch Logic

Pin 1 ─────┐
           │
        Switch
           │
Pin 2 ─────┘

Released state: The circuit is open — no electrical connection between the two contact pairs.
Pressed state: The circuit is closed — the internal dome contacts bridge the two contact pairs, completing the circuit.

The 4-pin configuration provides two pairs of internally connected pins. This design offers several benefits: redundant electrical contacts for improved reliability, enhanced mechanical stability on the PCB, and compatibility with standard SMT assembly processes.

For more detailed technical information, see our How Does Tact Switch Work? guide.

When integrating the TS-1109S into your PCB assembly process, several factors should be considered to ensure reliable soldering and performance.

1. Reflow Soldering Profile

The high-temperature housing material supports standard reflow soldering profiles. Ensure the peak temperature does not exceed the manufacturer’s recommended limits to prevent housing deformation or contact damage.

2. PCB Land Pattern

Use the manufacturer’s recommended land pattern for optimal solder joint reliability. The 4-pin configuration requires careful pad placement to ensure proper solder fillet formation.

3. Component Placement

Ensure accurate placement during pick-and-place assembly. The compact 4.5×4.5mm footprint requires precise positioning for consistent soldering and performance.

4. Mechanical Support

The 4-pin configuration provides stable mechanical support. For applications with high vibration or shock, consider additional mechanical support or adhesive to prevent stress on solder joints.

What Is a 4.5mm SMD Tact Switch?

A 4.5mm SMD tact switch is a compact surface-mount momentary push button with a 4.5×4.5mm footprint, designed for PCB integration in space-constrained electronic devices. The TS-1109S is a 4-pin version rated for 50mA at 12V DC, with operating force options of 180gf or 260gf and up to 100,000 mechanical cycles. This 4.5×4.5mm tact switch provides a crisp tactile response with a short 0.2mm travel, making it suitable for consumer electronics, IoT devices, industrial controls, and portable equipment.

Surface-mount tactile switches are widely used in electronic products because they provide reliable momentary switching in a compact, PCB-mountable package. The 4.5×4.5mm size offers a good balance between board space and tactile area — larger than 4×4mm switches but smaller than 6×6mm options.

4-Pin SMD Tact Switch — Configuration and Benefits

A 4 pin SMD tact switch offers several advantages over 2-pin alternatives. The four pins provide two pairs of internally connected contacts — two electrical contacts for the switching circuit and two mechanical anchor pins for enhanced PCB retention. This design improves reliability by providing redundant electrical connections and reduces the risk of solder joint failure under mechanical stress.

The TS-1109S uses a 4-pin configuration that supports automated SMT assembly and provides stable mechanical mounting. The 4-pin design distributes mechanical stress more evenly across the PCB, reducing the risk of pad lifting or component detachment in high-vibration environments.

Operating Force Selection — 180gf vs 260gf

The 4.5mm SMD tact switch is available in two operating force options. 180gf provides a lighter touch suitable for applications where users press the switch frequently, such as consumer electronics and remote controls. 260gf offers a more deliberate actuation feel, reducing the risk of accidental presses in industrial environments, control panels, or applications where the switch is operated in high-vibration conditions.

Selecting the right operating force is important for user experience and application reliability. Consider the end-user demographics, usage frequency, and environmental conditions when making your selection.

Applications Across Industries

This 4 pin SMT tact switch is widely used across multiple industries. Consumer electronics use it for remote controls, compact audio devices, handheld electronics, and control interfaces. IoT and smart devices use it for button controls on smart home products and compact wireless devices. Industrial controls use it for panel controls, reset functions, and user-interface buttons. Portable electronics and embedded systems also rely on the TS-1109S for compact PCB-mounted momentary switching.

SMD Assembly and Production Considerations

When integrating the TS-1109S into your PCB assembly process, consider the reflow soldering profile, PCB land pattern, component placement accuracy, and mechanical support requirements. The high-temperature housing material supports standard reflow soldering profiles, and the 4-pin configuration provides stable mechanical support for automated assembly.

Why Choose Vistar as Your Tactile Switch Supplier

Vistar Electronics is a trusted tactile switch manufacturer serving customers in consumer electronics, industrial automation, medical devices, and communication equipment. Our tactile switch lineup covers 4×4mm, 4.5×4.5mm, 5.2×5.2mm, 6×6mm, 12×12mm, and waterproof configurations with various operating forces and mounting options.

With ISO 9001:2015 certification and a commitment to continuous improvement, Vistar is your reliable partner for high-quality switching solutions. For more technical resources, including PCB layout guidelines and switch selection guides, visit our technical blog or contact our engineering support team directly.

Explore our full range of tactile switches and related content:

• Tactile Switches — Full Product Collection
• 4×4 SMD Tact Switch — TS-1187
• Ultra-Thin 4.5×4.5mm Tact Switch — TS-1198
• How Does Tact Switch Work?