The Benefits of a Compact Power Management IC and Power Loss Protection

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A power management integrated circuit (PMIC) manages power on an electronic device or in modules on devices with a wide voltage range. PMICs are employed for voltage conversion, voltage regulation, and battery management. They are essentially a system-in-a-package solution. A single PMIC can manage multiple external power sources, supply power to multiple loads, and shield against unsupported overvoltage and under-voltage conditions, over-currents, and thermal faults.

PMICs are extremely compact and significantly reduce both component count and overall solution size, reducing design time and cost. These features are used in numerous small devices such as wearables, hearables, sensors, and the Internet of Things (IoT). Most battery-operated devices, including smartphones and media players, incorporate PMICs out of necessity for their small size and low quiescent currents. PMICs provide a highly integrated, high-performance architecture for a broad range of application categories, such as storage and computing, networking, telecommunications, automotive, and consumer electronics.

Power Management ICs are configurable and can be programmed. They can be operated via firmware to function in diverse applications, eliminating the need for costly hardware circuitry changes. Examples of configurable options include output voltage, start-up time, slew rate, system-level sequencing, switching frequency, sleep modes, and operating modes.  A typical PMIC (Figure 1) contains a single or multiple switching DC-to-DC converters like buck, boost, or buck-boost converters, and linear regulators like LDOs. Many individual voltage rails can be present within a single PMIC and be capable of a low, medium, and high-voltage power level output.

Figure 1: Example of a High-Level Block Diagram of a PMIC

Power Loss Protection (PLP) Functionality

Any power failure, surge, or complete outage may potentially damage devices and corrupt data unless there exists an effective power loss protection (PLP) mechanism. A PMIC with PLP capabilities offers backup storage power during input power failure, and also ensures sufficient time for the storage or computing system to back up mission-critical data. Typical PLP solutions involve batteries and capacitors, which allow the completion of controller and flash functions during a power failure.

During normal operation, the PLP uses an integrated boost converter to charge a storage capacitor bank to a high voltage. This allows efficient energy storage, which is used to power the system in the event of a power loss. When input power goes away, an integrated buck converter regulates the storage voltage to a fixed output, so that the system can continue to operate flawlessly. Powering the system from the storage capacitors is called supplement mode. Supplement mode provides the system's power long enough to allow it time to back up critical data and shut down in a controlled way. Figure 2 shows a typical PLP system’s architecture.

Figure 2: Power Loss Protection (PLP) Embedded Circuitry

A typical PLP PMIC also incorporates an integrated autonomous health monitoring circuit that frequently checks the storage capacitor conditions to ensure there has not been any capacitance degradation. It effectively ensures that there is enough storage energy to power the system for a safe, controlled shutdown in the event of a power failure. Some PLP PMICs also implement a multichannel ADC to help monitor the power system parameters such as input power, storage capacitor voltage, and die temperature. The PLP solution also includes a hot-swap compatible e-Fuse that limits inrush current.

Qorvo, a provider of RF and power solutions, has introduced compact Power management ICs for battery powered, mid-power, and high-power applications and offers a combination of PMIC+PLP in one device. Qorvo’s ACTXXXX PMIC’s family is highly integrated and programmable, solving size challenges and providing system designers with design flexibility and control.

ACT81460 PMIC

The ACT81460 is a low power PMIC (Power Management Integrated Circuit) that is specifically designed for battery operated systems and is suitable for a variety of processor applications. It features very low standby current that prolongs battery life between charges, especially in applications requiring long standby or low power mode durations. It is a highly efficient PMIC that also enhances battery run-time during normal operating modes. The number of regulators that can be turned off or left on during low power modes is configurable and offers flexibility to optimize system efficiency. The IC includes four DC/DC converters with integrated power FETs, three low-dropout regulators (LDOs), and three load switches. Two of the DC/DC converters are step-down buck regulators, one is a step up/down buck-boost regulator and the fourth is a high voltage step-up boost regulator capable of providing up to 20 V. Each regulator can be configured for a wide range of output voltages through the I2C interface.

ACT88329 PMIC

The ACT88329 PMIC is an integrated ActiveCiPS power management integrated circuit. It powers a wide range of processors, including solid-state drive applications, video processors, FPGA’s, wearables, peripherals, and microcontrollers. The ACT88329 is optimized for SSD, FPGA and LPDDR5 applications. It is highly flexible and can be reconfigured via I2C for multiple applications without the need for PCB changes. The low external component count and high configurability significantly speeds time to market. Examples of configurable options include output voltage as low as 0.5V, startup time, slew rate, system level sequencing, switching frequency, sleep modes, operating modes, etc. The core of the device includes three DC/DC step down converters using integrated power FETs, two low-dropout regulators (LDOs). Buck1 and LDO1 can be configured as a load switch. Each DC/DC regulator switches at either 1.125MHz or 2.25MHz, requiring only three small components for operation. The LDOs only require small ceramic capacitors. All are highly configurable via the I2C interface.

ACT85610 PMIC

The ACT85610 PMIC is an integrated, highly-configurable multiple output power management unit with Power Loss Protection (PLP). The power loss protection provides backup storage power in the event of an input power failure. The ACT85610 includes four high-efficiency Bucks that can supply 3x 4A and 1x 2A current, with the output as low as 0.6V. A Boost regulator with 12V output and a fixed output Buck are in place to provide power for the IC and also supply power to the gate drivers in regulators for maximum efficiency. It covers the standard 3.3 V, 5 V, and 12 V power inputs for enterprise solid-state drive (SSD) applications, and also provides seven programmable general-purpose input/outputs (GPIOs) for status reporting, sequencing control, system auto discharge, and interrupts. The ACT85610 PMIC also implements autonomous storage capacitor health checking and accurate capacitance reading, enhanced system monitoring, and lifetime estimation.

ACT4752 PMIC

The ACT4752 PMIC is an effective solution for USB Power Delivery (PD) 3.0 and Programmable Power Supply (PPS) applications. The product combines a 5 V / 350 mA mini-buck converter and a 20 mA AUX LDO to simplify application system designs. It supports a wide input voltage range from 4.5 to 40 V and integrates both high and low sides. The product's main buck converter can be dynamically programmed to an output voltage between 3 and 24 V in 12.5 mV steps via the I2C interface or analog feedback. The ACT4752 is available in a 32-pin 25mm2 QFN package with a power-optimized footprint and exposed pad for improved thermal performance.

Power management plays a major role in virtually every piece of electronic equipment. If you'd like to know more about how to approach power management in your designs or products, click here for more information.