The **GS-R400V** is a high-efficiency, step-down (buck) switching regulator module belonging to the GS-R series, originally manufactured by STMicroelectronics. It is designed to provide a regulated voltage from a higher unregulated DC input. --- ### ## Technical Specifications The GS-R400V is known for its compact size and "ready-to-use" design, integrating several discrete electronic components into a single package. | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 7V to 40V DC | | **Output Voltage** | 5.1V (Fixed) | | **Output Current** | 4.0 Amperes (Max) | | **Efficiency** | Up to 90% | | **Switching Frequency** | ~100 kHz | | **Package Type** | Metal or Plastic SIP (Single In-line Package) | --- ### ### Internal Electronic Components The module is a "hybrid" circuit, meaning it contains several sub-components internally to function as a complete power supply: 1. **Switching Controller IC:** The "brain" of the module that uses Pulse Width Modulation (PWM) to regulate the output voltage. 2. **Power MOSFET:** An internal transistor acts as a high-speed switch to chop the input DC voltage. 3. **Power Inductor:** Stores energy during the "on" cycle of the switch and releases it during the "off" cycle to maintain a steady current flow. 4. **Schottky Diode:** Acts as a catch diode (freewheeling diode) to provide a path for the inductor current when the main switch is off. 5. **Filter Capacitors:** Internal ceramic or electrolytic capacitors used to reduce input and output voltage ripple. --- ### ### Key Features & Protection The GS-R400V is engineered to be robust for industrial and hobbyist applications: * **Short Circuit Protection:** The module will shut down or limit current if the output is shorted, preventing permanent damage. * **Thermal Shutdown:** If the internal temperature exceeds safe limits (usually due to high load or poor ventilation), the module deactivates. * **Remote Inhibit:** Includes a pin that allows the user to turn the output on or off using a logic signal. * **Adjustable Output:** While the "V" variant is often fixed at 5.1V, some versions allow for a small range of adjustment via an external resistor. --- ### ### Pinout Configuration The module typically features a 9-pin or 11-pin SIP layout. The primary pins are: * **Vi (Input):** Unregulated DC input. * **Go (Ground):** Common ground for input and output. * **Vo (Output):** Regulated 5.1V DC. * **Inhibit:** Logic input to enable/disable the regulator. * **S+ / S- (Sense):** Used for remote sensing to compensate for voltage drops over long wires.