The **PE45375** is a high-performance, HaRP™ technology-enhanced **Power Limiter** produced by pSemi (formerly Peregrine Semiconductor). It is designed to protect sensitive receiver components (like low-noise amplifiers) from high-power signals while maintaining signal integrity at lower power levels. --- ### ## Key Specifications and Features The following table summarizes the primary electrical and physical characteristics of the PE45375: | Feature | Specification | | :--- | :--- | | **Frequency Range** | 10 MHz to 6.0 GHz | | **Insertion Loss** | 0.4 dB @ 2 GHz; 0.8 dB @ 6 GHz | | **P1dB (Compression)** | +12 dBm to +15 dBm (Adjustable) | | **Max Input Power** | +38 dBm (CW) / +45 dBm (Pulsed) | | **Response Time** | < 1 nanosecond | | **Package Type** | 12-lead 3x3mm QFN | --- ### ### Core Functionality The PE45375 acts as a "safety valve" for RF front-ends. Its operation can be broken down into two modes: 1. **Passive Linear Mode:** When the input signal is below the threshold (Limiting Threshold), the device acts as a transparent path with very low insertion loss and high linearity. 2. **Limiting Mode:** When the input power exceeds the set threshold, the device increases its attenuation instantly to prevent the downstream components from being damaged or saturated. --- ### ### Distinctive Technical Advantages * **Adjustable Threshold:** Unlike traditional diode-based limiters, the PE45375 allows users to control the limiting threshold via an external resistor or voltage, providing flexibility for different LNA tolerances. * **HaRP™ Technology:** This proprietary technology eliminates gate-lag and ensures high linearity (IIP3), preventing the limiter itself from generating distortion products. * **No External Bias Required:** It can operate in a purely passive mode for power protection, though control pins are available for fine-tuning. * **Fast Recovery:** Once the high-power event ends, the device returns to its low-loss state in nanoseconds, ensuring minimal communication downtime. --- ### ### Typical Application Circuit In a standard RF front-end, the PE45375 is placed immediately after the antenna or switch and before the LNA: ```text [Antenna] --> [Band-Pass Filter] --> [PE45375 Limiter] --> [LNA] --> [Mixer/SoC] ``` This placement ensures that any "incoming spikes" (from lightning, nearby high-power transmitters, or radar) are clamped before reaching the sensitive CMOS or GaAs LNA. ---