The **PE3634** is a high-performance, monolithic **Prescaler** (frequency divider) manufactured by Peregrine Semiconductor (now pSemi, a Murata company). It is designed using UltraCMOS® technology, which allows for high frequency operation with very low power consumption. --- ### ## Technical Specifications The PE3634 is primarily used in Phase-Locked Loop (PLL) synthesis to divide high-frequency signals down to a range manageable by a frequency synthesizer. | Feature | Specification | | :--- | :--- | | **Function** | Divide-by-4 Prescaler | | **Frequency Range** | DC to 5.0 GHz | | **Supply Voltage** | 3.0 V (Nominal) | | **Operating Current** | 10 mA (Typical) | | **Package Type** | 8-lead MSOP / 6-lead DFN | | **Technology** | UltraCMOS® (Silicon on Sapphire) | --- ### ## Key Electronic Components & Features ### 1. UltraCMOS® Process Unlike standard bulk silicon, the PE3634 uses a **Silicon-on-Sapphire (SoS)** substrate. * **Benefit:** This provides superior isolation between circuit elements, resulting in significantly lower parasitic capacitance and higher linearity at microwave frequencies. ### 2. Divide-by-4 Core The internal logic consists of a chain of high-speed flip-flops configured to perform a fixed division. * **Input ($f_{in}$):** Accepts signals up to 5.0 GHz. * **Output ($f_{out}$):** Provides a signal at $f_{in} / 4$. If you input 4 GHz, the output will be 1 GHz. ### 3. I/O Interface * **Differential Inputs:** The device typically features differential RF inputs (CLK/CLK_N) to improve noise immunity and common-mode rejection. * **Single-Ended Output:** Usually designed to drive a standard CMOS or AC-coupled load. --- ### ## Common Applications The PE3634 is found in high-reliability and high-frequency communication systems: * **Fixed Wireless Access:** Point-to-point radio links. * **Satellite Communications:** L-Band and S-Band frequency synthesis. * **Test Equipment:** High-speed frequency counters and signal generators. * **Military/Aerospace:** Due to its radiation-tolerant nature (inherent to SoS technology). --- ### ## Application Circuit Diagram (Block Level) ```mermaid graph LR A[RF Input 5GHz] --> B(PE3634 Prescaler) B --> C[1.25GHz Output] C --> D[PLL Synthesizer / Phase Detector] ```