Power management chips (PMICs) are much more than just AC/DC and DC/DC converters, although these two are extremely important and fundamental components. Simply equating PMIC with AC/DC and DC/DC is inaccurate and a conceptual confusion.
We can understand it as follows:
Power Management IC (PMIC) is a broad term for:
It refers to all integrated circuits used for managing, distributing, converting, monitoring, and protecting electrical energy in electronic systems.
Objective: To ensure that all components in the system (CPU, memory, sensors, display screen, etc.) receive the required, accurate, and stable voltage and current, while optimizing efficiency, extending battery life, and protecting system safety.
The scope of functions is very broad.
AC/DC and DC/DC converters are the core functional modules of PMIC:
AC/DC converter: This is a key step in converting AC mains power (such as 110V/220V) into the required DC voltage (such as 12V, 5V) inside the device. The core of a common charger adapter is the AC/DC conversion chip (or module).
DC/DC converter: This is the most common and diverse part of PMIC. It is responsible for converting one DC voltage into another DC voltage (boost, buck, buck boost, reverse phase). For example:
Step down the main power supply of the system (such as 3.7V from the battery or 5V from the adapter) to 1.2V required by the CPU.
Step up the battery voltage to the 15V required to drive the backlight of the display screen.
Generate negative voltage for use in certain specific circuits.
They are the core technologies for achieving the fundamental requirement of 'electricity conversion'.
PMIC contains rich content that goes far beyond conversion functions:
Linear regulator: Although its efficiency is usually lower than that of DC/DC switching converters, it is very important in scenarios that require extremely low noise, simple circuits, or small currents (such as LDO low dropout linear regulators).
Battery management:
Charging management: Control the charging process of the battery (constant current, constant voltage, trickle charging, temperature monitoring, etc.).
Electricity meter: Accurately monitor the remaining charge (SoC) and health status (SoH) of the battery.
Protection: Prevent battery overcharging, overdischarging, overcurrent, and overheating.
Battery certification: Communicate with smart batteries.
Power path management: Intelligent management of the power path between input power sources (such as adapters, USB, wireless charging) and batteries, achieving seamless switching, prioritizing adapter power supply, OTG power supply, etc.
Voltage monitoring and sorting:
Voltage monitor: Monitor whether the critical voltage is within the normal range and issue a reset signal when abnormal.
Power timing control: Accurately controlling the power on and off sequence of multiple voltage rails in a system is crucial for stable startup and shutdown of complex chips such as processors and FPGAs.
Load switch: controls the power supply on/off of sub circuits or modules, used for modular power supply and deep energy saving.
LED driver: controls the brightness and current of the display backlight or status indicator lights (usually also an application of DC/DC or constant current source).
Thermal management interface: Monitoring chip temperature or system power management chip (PMIC) is much more than just AC/DC and DC/DC converters, although these two are extremely important and fundamental parts. Simply equating PMIC with AC/DC and DC/DC is inaccurate and a conceptual confusion.
We can understand it as follows:
Power Management IC (PMIC) is a broad term for:
It refers to all integrated circuits used for managing, distributing, converting, monitoring, and protecting electrical energy in electronic systems.
Objective: To ensure that all components in the system (CPU, memory, sensors, display screen, etc.) receive the required, accurate, and stable voltage and current, while optimizing efficiency, extending battery life, and protecting system safety.
The scope of functions is very broad.
AC/DC and DC/DC converters are the core functional modules of PMIC:
AC/DC converter: This is a key step in converting AC mains power (such as 110V/220V) into the required DC voltage (such as 12V, 5V) inside the device. The core of a common charger adapter is the AC/DC conversion chip (or module).
DC/DC converter: This is the most common and diverse part of PMIC. It is responsible for converting one DC voltage into another DC voltage (boost, buck, buck boost, reverse phase). For example:
Step down the main power supply of the system (such as 3.7V from the battery or 5V from the adapter) to 1.2V required by the CPU.
Step up the battery voltage to the 15V required to drive the backlight of the display screen.
Generate negative voltage for use in certain specific circuits.
They are the core technologies for achieving the fundamental requirement of 'electricity conversion'.
PMIC contains rich content that goes far beyond conversion functions:
Linear regulator: Although its efficiency is usually lower than that of DC/DC switching converters, it is very important in scenarios that require extremely low noise, simple circuits, or small currents (such as LDO low dropout linear regulators).
Battery management:
Charging management: Control the charging process of the battery (constant current, constant voltage, trickle charging, temperature monitoring, etc.).
Electricity meter: Accurately monitor the remaining charge (SoC) and health status (SoH) of the battery.
Protection: Prevent battery overcharging, overdischarging, overcurrent, and overheating.
Battery certification: Communicate with smart batteries.
Power path management: Intelligent management of the power path between input power sources (such as adapters, USB, wireless charging) and batteries, achieving seamless switching, prioritizing adapter power supply, OTG power supply, etc.
Voltage monitoring and sorting:
Voltage monitor: Monitor whether the critical voltage is within the normal range and issue a reset signal when abnormal.
Power timing control: Accurately controlling the power on and off sequence of multiple voltage rails in a system is crucial for stable startup and shutdown of complex chips such as processors and FPGAs.
Load switch: controls the power supply on/off of sub circuits or modules, used for modular power supply and deep energy saving.
LED driver: controls the brightness and current of the display backlight or status indicator lights (usually also an application of DC/DC or constant current source).
Thermal management interface: monitors chip temperature or system temperature, participates in adjusting power consumption or triggering protection.
Interface and Control: Modern complex PMICs typically communicate with the system main controller through digital interfaces such as I2C, SPI, SPMI, etc., accepting configurations and reporting status.
Summary:
AC/DC and DC/DC converters are key components responsible for the core "voltage conversion" task in power management ICs. Without them, PMIC loses its basic functions.
Power management IC is a much broader concept. It not only includes AC/DC and DC/DC conversion, but also integrates a series of functional modules for comprehensive management of system power, such as battery management, voltage monitoring, timing control, load switching, interface control, etc. A complex SoC system (such as mobile phones, tablets, laptops) typically uses one or more highly integrated PMIC chips, which contain various DC/DC converters LDO、 Chargers, power meters, timing controllers, and other units.
Therefore, it can be said that AC/DC and DC/DC are the core and basic functions of power management ICs, but the connotation and extension of power management ICs are far greater than this. They are the relationship between "core components" and "complete solutions". Temperature, participate in regulating power consumption or triggering protection.
Interface and Control: Modern complex PMICs typically communicate with the system main controller through digital interfaces such as I2C, SPI, SPMI, etc., accepting configurations and reporting status.
Summary:
AC/DC and DC/DC converters are key components responsible for the core "voltage conversion" task in power management ICs. Without them, PMIC loses its basic functions.
Power management IC is a much broader concept. It not only includes AC/DC and DC/DC conversion, but also integrates a series of functional modules for comprehensive management of system power, such as battery management, voltage monitoring, timing control, load switching, interface control, etc. A complex SoC system (such as mobile phones, tablets, laptops) typically uses one or more highly integrated PMIC chips, which contain various DC/DC converters LDO、 Chargers, power meters, timing controllers, and other units.
Therefore, it can be said that AC/DC and DC/DC are the core and basic functions of power management ICs, but the connotation and extension of power management ICs are far greater than this. They are the relationship between "core components" and "complete solutions".