The **PI2126** is a high-performance, self-contained **Active ORing Controller** solution with an integrated internal MOSFET. It is designed by Vicor (Picor) to replace traditional high-loss Schottky diodes in redundant power system architectures. --- ### 1. Key Technical Specifications The PI2126 is specifically optimized for low-voltage systems requiring high efficiency and high current density. | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 8V to 15V | | **Continuous Load Current** | Up to 12A | | **Peak Current (Pulsed)** | Up to 100A | | **Internal MOSFET RDS(on)** | 4.5 mΩ (typical) | | **Package Type** | 7mm x 8mm Land Grid Array (LGA) | | **Turn-off Speed** | 80ns (Reverse Fault Response) | --- ### 2. Core Components and Internal Logic The device integrates several electronic sub-systems into a single package to simplify PCB design: * **Integrated N-Channel MOSFET:** Unlike standalone controllers that require an external transistor, the PI2126 includes a 4.5 mΩ power switch. * **High-Speed Comparator:** Continuously monitors the voltage differential between the input (Vin) and output (Vout). If a reverse current condition is detected (e.g., an input source failure), it triggers an ultra-fast shutdown. * **Charge Pump:** Since it uses an N-channel MOSFET as a high-side switch, an internal charge pump generates the necessary gate-drive voltage higher than the input rail. * **Fault Reporting (FT Pin):** An open-collector output that pulls low to signal a fault condition (such as UVLO or thermal shutdown). --- ### 3. Functional Pins and Connections | Pin Name | Description | | :--- | :--- | | **VIN** | Input Power Source connection. | | **VOUT** | Output connection to the Load/Bus. | | **VC** | Bias Supply Input (Requires a small decoupling capacitor). | | **GND** | Signal and Power Ground. | | **FT** | Fault Flag; indicates internal MOSFET failure or over-temperature. | | **BK** | Bus Kick; used to discharge the output if necessary. | --- ### 4. Why use PI2126 instead of a Diode? 1. **Efficiency:** A standard Schottky diode at 10A might have a 0.5V drop ($5W$ loss). The PI2126 at 10A ($I^2 \times R$) results in only $10^2 \times 0.0045 = 0.45W$ loss. 2. **Thermal Management:** Reduced power dissipation means smaller heatsinks or simpler PCB copper cooling. 3. **Reverse Protection:** It prevents a shorted power supply from pulling down the entire redundant power bus by disconnecting the input within nanoseconds. --- ### 5. Application Circuit Example ```mermaid graph LR subgraph PI2126 A[VIN] --> B[Internal MOSFET] B --> C[VOUT] D[Comparator] -.-> B end Source((PSU 12V)) --> A C --> Bus((Common Load Bus)) ```