## Overview of CMPWR Components The term **CMPWR** typically refers to a specialized series of **Smart Power Management** Integrated Circuits (ICs), originally developed by California Micro Devices (now part of ON Semiconductor). These parts are primarily designed for power sequencing, voltage regulation, and power state management in computing environments (desktops, laptops, and servers). --- ### 1. Primary Functions CMPWR parts are engineered to handle the transition between different power states (such as ACPI sleep modes). Their core responsibilities include: * **VCC_LIMIT Management:** Ensuring the logic levels stay within safe operating boundaries. * **Dual Power Path Switching:** Automatically switching between a main power supply (e.g., +5V) and a backup/auxiliary supply (e.g., +5V_Standby). * **Glitch-Free Transitions:** Preventing system resets or data loss during power source handovers. --- ### 2. Key Component Categories The CMPWR series is categorized based on the specific power task they perform: | Part Category | Primary Purpose | Common Application | | :--- | :--- | :--- | | **LDO Regulators** | Provide stable, low-noise voltage. | Powering sensitive chipsets and I/O. | | **Power Shifters** | Switch between Main and Standby power. | USB Power management, Sleep modes. | | **SmartReg** | Integrated LDO with switching logic. | Logic power for Motherboards. | | **Termination** | Active termination for high-speed buses. | DDR Memory and SCSI termination. | --- ### 3. Popular CMPWR Parts and Descriptions #### CMPWR130 This is one of the most common "SmartReg" devices. It is a dual-input low dropout (LDO) regulator. - **Mechanism:** It monitors the "Main" power. If Main power falls below a threshold, it seamlessly switches to "Auxiliary" power to keep the real-time clock or wake-on-LAN features active. #### CMPWR330 Typically used for **USB Peripheral Power**. - It ensures that USB devices receive constant power even when the computer is in "Sleep" mode by routing power from the standby rail. --- ### 4. Technical Specifications Block Most CMPWR parts share these common technical traits: ```yaml Standard_Features: - Input_Voltage_Range: 3.3V to 5.5V - Output_Current: 150mA to 1.5A (depending on model) - Protection: Thermal shutdown and current limiting - Package_Types: SOIC-8, MSOP-8, SOT-23 - Efficiency: Optimized for low dropout voltage to reduce heat ``` --- ### 5. Why they are used In modern electronics, simply connecting a battery to a chip is insufficient. CMPWR parts provide **intelligence**. They detect when a user presses the power button or when a system enters "Hibernation," ensuring that the correct sub-systems stay powered while others shut down to save energy.