The **V28A5T175B3** is a high-density, isolated DC-DC converter module belonging to the **Maxi** series manufactured by **Vicor Corporation**. It is designed for industrial and military-grade applications where high reliability and power density are required. --- ### 1. General Specifications This module is part of Vicor's 2nd Generation family, utilizing high-frequency Zero Current Switching (ZCS) and Zero Voltage Switching (ZVS) topology. | Feature | Specification | | :--- | :--- | | **Input Voltage (Nominal)** | 28 VDC | | **Input Voltage Range** | 18 – 36 VDC | | **Output Voltage** | 5 VDC | | **Output Power** | 175 Watts | | **Output Current** | 35 Amps | | **Efficiency** | ~82% - 84% | | **Package Size** | Maxi (4.6" x 2.2" x 0.5") | | **Isolation Voltage** | 3,000 Vrms (Input to Output) | --- ### 2. Key Electronic Features The V28A5T175B3 incorporates several advanced control and protection circuits: * **ZCS/ZVS Topology:** Unlike traditional PWM converters, this module switches at zero current or zero voltage. This significantly reduces switching losses and Electromagnetic Interference (EMI). * **Remote Sensing:** Compensates for voltage drops across the output leads by monitoring the voltage directly at the load. * **Trim Capability:** The output voltage can be adjusted (trimmed) via the `SC` (Secondary Control) pin, typically ranging from 10% to 110% of the nominal 5V. * **Logic Compatibility:** Includes a Primary Control (PC) pin for remote sequencing and disabling the module. --- ### 3. Pinout Configuration The "Maxi" package uses a standard pin layout for integration into PCB or chassis-mount systems. | Pin Type | Name | Function | | :--- | :--- | :--- | | **Input** | +IN / -IN | Primary DC supply input (18-36V). | | **Control** | PC (Primary Control) | Module enable/disable and status. | | **Control** | PR (Parallel) | Used for synchronizing multiple units for higher power. | | **Output** | +OUT / -OUT | Regulated 5V output. | | **Secondary** | SC (Secondary Control) | Output voltage trimming/adjustment. | | **Sense** | +S / -S | Remote sense leads for voltage accuracy. | --- ### 4. Protection Mechanisms The internal circuitry is designed to prevent damage during fault conditions: 1. **Overvoltage Protection (OVP):** Shuts down the module if the output voltage exceeds a safe threshold. 2. **Overcurrent/Short Circuit Protection:** Limits the current to prevent thermal runaway. 3. **Thermal Shutdown:** Internal sensors disable the unit if the baseplate temperature exceeds $100^{\circ}C$. ---