PMIC (Power Management IC) is used to manage power devices in the host system and is commonly used in cell phones and various mobile terminal devices.

Ⅰ The role of PMIC

The PMIC (Power Management Integrated Circuit) is a chip that is responsible for the conversion, distribution, detection, and other power management of electrical energy in the electronic equipment system. It is mainly responsible for identifying the power supply amplitude of the CPU, generating the corresponding short moment wave, and driving the subsequent circuit to output power. Commonly used power management chips are HIP6301, IS6537, RT9237, ADP3168, KA7500, TL494, etc.

In 1958, Texas Instruments (TI) engineer Jack Kilby invented the integrated circuit. This electronic component called a chip opened a new era of signal processing and power electronic equipment. Kilby also relied on this invention won the Nobel Prize in Physics in 2000.

All electronic devices have power sources, but different systems have different requirements for power sources. To give full play to the best performance of the electronic system, the most suitable power management method needs to be selected.

PMIC-me8305 sop8 5w

First of all, the core of electronic devices is a semiconductor chip. To increase the density of the circuit, the feature size of the chip is always moving towards a decreasing trend. The electric field intensity increases linearly with the decrease of the distance. If the power supply voltage is still the original 5V, the electric field intensity generated is sufficient to break the chip. Therefore, in this way, the electronic system's requirements for power supply voltage have changed, that is, different step-down power supplies are required. To maintain high efficiency while stepping down, step-down switching power supplies are generally used.

Secondly, many electronic systems also require a power supply higher than the power supply voltage. For example, in battery-powered devices, the backlight power supply for driving liquid crystal displays, ordinary white LED drivers, etc., all need to boost the system power supply, which requires the use of boost pressure type switching power supply.

Besides, modern electronic systems are developing in the direction of high speed, high gain, and high reliability. Small interference in the power supply has an impact on the performance of electronic equipment. This requires a power supply with advantages in terms of noise and ripple. The system power supply performs processing such as voltage stabilization and filtering, which requires the use of a linear power supply. The above-mentioned different power management methods can be realized through the corresponding power chip combined with very few peripheral components. It can be seen that the development of power management chips is an indispensable means to improve the performance of the whole machine.

Ⅱ Basic types of PMIC

The scope of power management is relatively wide, including separate electric energy conversion (mainly DC to DC, that is, DC/DC), separate electric energy distribution and detection, and a system that combines electric energy conversion and electric energy management.

Correspondingly, the classification of PMIC (power management integrated circuits) also includes these aspects, such as linear power chips, voltage reference chips, switching power supply chips, LCD driver chips, LED driver chips, voltage detection chips, battery charging management chips, etc.

LED driver chip

Some of the main power management chips are dual in-line chips, and some are surface-mount packages. The HIP630x series of chips are classic power management chips, designed by the famous chip design company Intersil. It supports a two/three/four-phase power supply and supports VRM9.0 specification. The voltage output range is 1.1V-1.85V, the output can be adjusted at 0.025V intervals, the switching frequency is up to 80KHz. With a large power supply, small ripple, and internal resistance Small and other characteristics, it can precisely adjust the CPU power supply voltage.

Common power management IC

In daily life, people rely more and more on electronic equipment, and the upgrading of electronic technology also means that people have high hopes for the development of power technology. The main classification of power management technology is introduced below.

Power management semiconductors clearly emphasize the position and function of power management integrated circuits from the included devices. Power management semiconductors include two parts, namely power management integrated circuits and power management discrete semiconductor devices.

Power management integrated circuits include many categories, roughly divided into two aspects: voltage regulation and interface circuits. The voltage regulator includes a linear low-dropout regulator (ie LDO), and a series of positive and negative output circuits. Also, there are no pulse width modulation (PWM) type switching circuits.

Due to technological progress, the physical size of digital circuits in integrated circuit chips is getting smaller and smaller, so the working power supply is developing towards low voltage, and a series of new voltage regulators have emerged.

Interface circuits for power management mainly include interface drivers, motor drivers, power field-effect transistor (MOSFET) drivers, and high-voltage/high-current display drivers.

Discrete semiconductor devices for power management include some traditional power semiconductor devices, which can be divided into two categories. One type contains rectifiers and thyristors; the other type is triode type, which contains power bipolar transistors and contains power field-effect transistor (MOSFET) and insulated gate bipolar transistor (IGBT), etc.

To some extent, it is precise because of the massive development of power management ICs that power semiconductors have been renamed power management semiconductors. It is because so many integrated circuits (ICs) have entered the power supply field that people call more power management at the current stage of power technology.

The dominant part of the power management semiconductor is the power management IC, which can be roughly summarized into the following 8 types.

1. AC/DC modulation IC containing low voltage control circuit and high voltage switching transistor;

2. DC/DC modulation IC, including boost/buck regulator, and charge pump;

3. Power factor control PFC pre-modulation IC, providing power input circuit with power factor correction function;

4. Pulse modulation or pulse amplitude modulation PWM/ PFM control IC, which is a pulse frequency modulation and/or pulse width modulation controller, and used to drive external switches;

5. Linear modulation IC (such as linear low-dropout regulator LDO, etc.), including positive and negative regulators, and low-dropout LDO modulator tubes;

6. Battery charging and management IC. Including battery charging, protection and power display IC, as well as battery data communication "smart" battery IC;

7. Hot-swap board control IC (avoid the influence of inserting or removing another interface from the working system);

8. Switch function IC of MOSFET or IGBT.

Among these power management ICs, voltage regulation ICs are the fastest growing and most productive part. Various power management ICs are related to some related applications, so for different applications, more types of devices can be listed.

The technical trend of power management is high efficiency, low power consumption, and intelligence. Improving efficiency involves two different aspects: on the one hand, we want to maintain the overall efficiency of energy conversion, and at the same time we want to reduce the size of the equipment; on the other hand, the size of the protection remains unchanged, which greatly improves efficiency.

Ⅲ Applications of PMIC  

1. Specific application

Step-down dc-dc converter lm2596s

If the following conditions are required: the designed circuit requires the power supply to have high noise and ripple suppression; a small PCB board area (such as mobile phones and other handheld electronic products); the circuit power supply does not allow the use of inductors (such as mobile phones); the power supply needs to have instantaneous calibration and output state self-checking function; low voltage drop of the regulator, low power consumption, low circuit cost, and simple solution, then the linear power supply is the most appropriate choice.

This power supply includes the following technologies: precise voltage reference, high-performance, low-noise operational amplifier, low-dropout regulator, and low quiescent current.

On occasions such as low-power power supply, op-amp negative power supply, LCD/LED drive, etc., capacitor-based switching power supply chips are often used, which is commonly referred to as charge pump.

There are many chip products based on the working principle of the charge pump, such as AAT3113, which is a white LED driver chip composed of a low-noise, constant-frequency charge pump DC/DC converter.

AAT3113 uses fractional times (1.5X) conversion to improve efficiency. The device drives 4 LEDs in parallel, with an input voltage range of 2.7V to 5.5V, and can provide approximately 20mA of current for each output. The device also has a thermal management system feature to protect any short circuits that occur on the output pins. Its embedded soft-start circuit can prevent current overshoot during startup. AAT3113 uses a simple serial control interface to enable and shut down the chip and 32-level logarithmic scale brightness control.

Inductance-based DC/DC chips have the widest range of applications. Applications include handheld computers, cameras, spare batteries, portable instruments, microphones, motor speed control, display bias, and color adjusters.

The main technologies include BOOST structure current mode loop stability analysis, BUCK structure voltage mode loop stability analysis, BUCK structure current mode loop stability analysis, over current, over-temperature, over-voltage, and soft start protection functions, synchronization rectification technology analysis, reference voltage technology analysis.

In addition to basic power conversion chips, power management chips also include power control chips for rational use of power. Such as NiH battery intelligent fast charging chip, lithium-ion battery charging and discharging management chip, lithium-ion battery overvoltage, overcurrent, overtemperature, short circuit protection chip.

A chip for switching management between the line power supply and backup battery, USB power management chip; charge pump, multiple LDO power supply, power-on sequence control, multiple protections, complex power supply chip for battery charge, and discharge management, etc. Especially in consumer electronics, for example, portable DVDs, mobile phones, digital cameras, etc., can provide complex multi-channel power with almost one to two power management chips, so that the performance of the system can be maximized.

2. Application range

The application range of PMIC is very wide. The development of a power management integrated circuit is of great significance to improve the performance of the whole machine. The choice of power management integrated circuits is directly related to the needs of the system, and the development of digital power management chips needs to overcome cost difficulties.

The power management chip is responsible for the transformation, distribution, detection, and other power management of electric energy in the electronic equipment system. Power management chips are indispensable to electronic systems, and their performance has a direct impact on the performance of the whole machine.

The scope of power management is relatively wide, including separate electric energy conversion (mainly DC to DC, that is, DC/DC), separate electric energy distribution and detection, and a system that combines electric energy conversion and electric energy management. Correspondingly, the classification of power management chips also includes these aspects, such as linear power chips, voltage reference chips, switching power supply chips, LCD drive chips, LED drive chips, voltage detection chips, battery charging management chips, and so on. The following briefly introduces the main types and applications of power management chips.