The **KMS-2-R/K** is a high-performance, subminiature surface-mount (SMT) tactile switch manufactured by **C&K Components** (now part of Littelfuse). It is widely used in compact electronic devices where space is at a premium and reliability is critical. --- ### ## Technical Specifications The following table summarizes the key electrical and mechanical characteristics of the KMS-2-R/K: | Feature | Specification | | :--- | :--- | | **Contact Type** | SPST, NO (Normally Open) | | **Actuation Force** | 2.0 N (approx. 200 grams) | | **Operating Life** | 100,000 cycles | | **Max Voltage** | 32 VDC | | **Max Current** | 50 mA | | **Terminal Type** | Gullwing (SMT) | | **Dimensions** | 4.6 x 2.8 x 1.55 mm | | **IP Rating** | IP40 (Standard protection) | --- ### ## Key Electronic Features 1. **Subminiature Profile:** The "KMS" series is designed for side-actuation. This allows the switch to be mounted on the edge of a PCB, reducing the overall height requirements for the device housing. 2. **Tactile Feedback:** The "2" in the part number typically signifies the actuation force. At **2.0 Newtons**, it provides a crisp, audible "click" and physical resistance, which is essential for user confirmation in small interfaces. 3. **Construction Materials:** * **Contacts:** Usually silver-plated (R) to ensure low contact resistance (<100 mΩ). * **Base:** Heat-resistant thermoplastic, capable of withstanding lead-free infrared (IR) reflow soldering temperatures. 4. **K/R Designations:** * **R:** Indicates that the part is supplied on **Reels** (Tape & Reel packaging) for automated pick-and-place assembly. * **K:** Refers to the specific series variant, often indicating the physical termination style or the "LFS" (Lead-Free Silver) compliance. --- ### ## Common Applications Due to its small footprint and side-actuated design, the KMS-2-R/K is commonly found in: * **Mobile Phones:** Volume rockers or power buttons. * **Wearables:** Smartwatches and fitness trackers. * **Medical Devices:** Handheld diagnostic tools. * **Consumer Electronics:** Bluetooth headsets and remote controls. ---