## Overview of the TPS1663 (eFuse) The **TPS1663** is a high-voltage integrated **eFuse** (electronic fuse) designed by Texas Instruments. It is used to protect circuits from overvoltage, overcurrent, and short-circuit conditions. It is commonly used in industrial automation, PLC modules, and power supply protection. --- ### 1. Key Technical Specifications The TPS1663 operates over a wide input range and provides several adjustable protection features. | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 4.5 V to 60 V | | **Maximum Output Current** | 6 A | | **Internal MOSFET On-Resistance ($R_{DS(on)}$)** | ~31 mΩ | | **Current Limit Accuracy** | ±7% (at high current) | | **Package** | 24-pin VQFN (4mm x 4mm) | --- ### 2. Main Functional Pins To understand the electronic parts of the TPS1663 system, you must understand these primary pin functions: * **IN / OUT:** The power input and protected output pins. * **ILIM:** Connects a resistor to ground to set the current limit threshold. * **UVLO / OVLO:** Resistor dividers are used here to set the Under-Voltage Lockout and Over-Voltage Lockout thresholds. * **dVdT:** A capacitor connected here controls the output voltage ramp rate (soft-start). * **IMON:** Provides an analog voltage proportional to the load current for monitoring. * **FLT:** An open-drain output that pulls low during a fault (overcurrent, thermal shutdown). --- ### 3. Core Protection Mechanisms #### A. Overcurrent Protection (OCP) The device monitors current through the internal MOSFET. If the current exceeds the limit set by the **ILIM** resistor, the device either limits the current or shuts down after a blanking time, depending on the specific model variant (Latch-off vs. Auto-retry). #### B. Adjustable Overvoltage Protection By using a resistor divider on the **OVLO** pin, you can define the exact voltage at which the eFuse should disconnect the load to prevent damage from power surges. #### C. Thermal Shutdown If the internal junction temperature exceeds approximately **160°C**, the TPS1663 turns off the internal power switch to prevent permanent damage to the silicon. #### D. Reverse Current Blocking (Optional) When used with an external MOSFET, the TPS1663 can provide protection against reverse current flow, which is critical for redundant power supplies. --- ### 4. Typical Application Circuit ```text [Power Source] --> [TPS1663 IN] ---- (Internal Switch) ---- [TPS1663 OUT] --> [Load] | | [UVLO/OVLO] [C-dVdT] (Resistors) (Capacitor) ``` ---