The **PLL520-17SC-R** is a low-power, high-performance Phase Locked Loop (PLL) based frequency multiplier produced by PhaseLink (now part of Microchip Technology). It is specifically designed to generate high-speed differential outputs from lower-frequency crystal or clock inputs. --- ### 1. General Specifications Below are the primary technical parameters for the PLL520-17SC-R: | Parameter | Specification | | :--- | :--- | | **Output Type** | PECL (Positive Emitter-Coupled Logic) | | **Input Frequency Range** | 20MHz to 44MHz | | **Output Frequency Range** | 100MHz to 200MHz | | **Supply Voltage (Vcc)** | 3.3V (± 10%) | | **Operating Temperature** | 0°C to +70°C (Commercial) | | **Package Type** | SOP-8 (Small Outline Package, 8 pins) | | **Mounting Type** | Surface Mount (SMD/SMT) | --- ### 2. Core Functional Components The internal architecture of this IC consists of several key electronic sections: 1. **Crystal Oscillator Interface:** Designed to work with a fundamental mode crystal. It includes internal circuitry to stabilize the input frequency. 2. **Phase Locked Loop (PLL):** The heart of the chip. It takes the reference input and multiplies the frequency using a Voltage Controlled Oscillator (VCO). 3. **Frequency Multiplier:** Specifically configured for a **4x multiplication** ratio. For example, a 25MHz crystal input will result in a 100MHz output. 4. **PECL Output Driver:** Provides differential PECL outputs (Out and Out_Bar). These are high-speed signals used to minimize noise and electromagnetic interference (EMI). --- ### 3. Pin Configuration (SOP-8) | Pin # | Name | Description | | :--- | :--- | :--- | | 1 | XIN | Crystal Input or Reference Clock Input | | 2 | XOUT | Crystal Output (Leave floating if using a clock) | | 3 | VDD | Power Supply (3.3V) | | 4 | GND | Ground | | 5 | OUT | PECL Differential Output | | 6 | /OUT | Complementary PECL Differential Output | | 7 | OE | Output Enable (High = Active, Low = High Impedance) | | 8 | NC/FIN | No Connect or Factory Test Pin | --- ### 4. Key Application Use-Cases * **Networking Gear:** Used in Gigabit Ethernet and Fibre Channel equipment to generate stable timing signals. * **Storage Area Networks (SAN):** High-speed data transfer timing. * **Clock Distribution:** Providing synchronized clock signals across complex PCBs with low jitter requirements. --- ### 5. Part Number Breakdown * **PLL520-17:** The specific series and designator for the 4x multiplication PECL family. * **S:** Package type (SOP). * **C:** Commercial temperature range. * **R:** Tape and Reel packaging (standard for automated SMT assembly).