The **MA74TBD-R** is a specific electronic component, typically identified as a **tactile switch** (or tact switch) manufactured by companies like **CIT Relay & Switch**. These components are fundamental in human-machine interfaces, providing physical feedback when pressed. --- ## 1. Component Specifications The MA74TBD-R belongs to a series of sub-miniature tactile switches designed for high-density mounting. | Parameter | Specification | |:---|:---| | **Switch Type** | Tactile Switch (Momentary) | | **Mounting Type** | Surface Mount (SMD / SMT) | | **Actuator Height** | Usually 1.5mm to 3.5mm (depending on specific sub-code) | | **Operating Force** | 160gF to 260gF (typical) | | **Contact Material** | Silver Plated (Standard) | | **Lifecycle** | ~100,000 to 500,000 cycles | | **Terminal Style** | "Gull Wing" or "J-Lead" SMT terminals | --- ## 2. Key Features and Design * **Small Footprint:** Designed for PCB applications where space is at a premium (e.g., mobile devices, remote controls). * **Tactile Feedback:** Provides a clear "click" sensation to the user, confirming that the circuit has been closed. * **Tape and Reel Packaging:** The "-R" suffix usually denotes that the parts are supplied on a **Reel**, making them compatible with automated pick-and-place assembly machines. * **Sealing:** These models are often designed to be splash-resistant or wash-tight to withstand soldering processes. --- ## 3. Typical Applications The MA74 series is versatile and found in numerous consumer and industrial electronics: 1. **Consumer Electronics:** Volume buttons on tablets, power buttons on cameras, and navigation keys on small appliances. 2. **Instrumentation:** Reset buttons on medical devices or industrial controllers. 3. **Telecommunications:** Handheld radios and interface panels. --- ## 4. Part Number Breakdown (Typical) While naming conventions vary slightly by manufacturer, the code generally breaks down as follows: * **MA:** Series prefix (Miniature/Sub-miniature Tactile). * **74:** Dimensional indicator (Specific size, e.g., 6x6mm or 4x4mm). * **TB:** Terminal/Actuator style (Top Actuated, Surface Mount). * **D:** Actuation Force indicator (e.g., 160gF). * **-R:** Packaging (Reel).