Products >> Power Management (PMIC) >> Power driver IC

Power driver IC (Integrated Circuit), that is, power driver integrated circuit, is a circuit that integrates a large number of microelectronic components (such as transistors, resistors, capacitors, etc.) on a semiconductor chip and is used to control and drive power supply equipment.

In terms of function
- Voltage conversion:
  - It can realize various voltage conversion functions. For example, in AC-DC (alternating current - direct current) conversion, the power driver IC can convert the input alternating voltage (such as mains voltage 220V) into a stable direct voltage. This is because its internal circuit structure can perform operations such as rectification and filtering on alternating signals. For example, in a mobile phone charger, the power driver IC inside first converts 220V alternating current into high-voltage direct current, and then converts it into a low-voltage direct current suitable for mobile phone charging (such as 5V or 9V) through subsequent circuits.
  - In DC-DC conversion, it can change the magnitude of the direct voltage. For example, in a notebook computer, the power driver IC can convert the battery output voltage (such as 10.8V - 11.1V, etc.) into different direct voltages to provide suitable voltages for different components inside the computer, such as the processor (which may require 1V - 1.5V) and the hard disk (which may require 5V).
- Current control:
  - The power driver IC can precisely control the magnitude of the output current. Taking LED lighting as an example, LED lights have strict requirements on current. Excessive current can easily damage LEDs, and too little current will not be bright enough. The power driver IC can ensure that the current flowing through the LED remains at a stable value through a constant current control circuit, thereby ensuring the normal lighting and lifespan of the LED.
- Power regulation:
  - It can adjust the output power of the power supply. In some high-power application scenarios, such as industrial power supplies or high-power server power supplies, the power driver IC can reasonably allocate power according to the needs of the load and improve the usage efficiency of the power supply. For example, when the CPU load of a server is low, the power driver IC can reduce the power provided to the CPU and reduce energy waste.
Working principle
- Based on PWM (pulse width modulation) technology:
  - Many power driver ICs adopt PWM principle. The PWM signal is a signal with a fixed frequency but variable pulse width. Taking a DC-DC buck converter as an example, after the power driver IC receives the input voltage, it will generate a PWM signal to control the conduction and shutdown of the switching tube (such as MOSFET). In one cycle, when the PWM signal is high, the switching tube is turned on, the input voltage charges the inductor and supplies power to the load at the same time; when the PWM signal is low, the switching tube is turned off, and the inductor releases energy to the load through the freewheeling diode. By adjusting the duty cycle of the PWM signal (that is, the ratio of pulse width to period), the output voltage can be controlled. For example, the larger the duty cycle, the higher the output voltage; the smaller the duty cycle, the lower the output voltage.
- Feedback control mechanism:
  - Power driver ICs usually also include feedback control circuits. Taking a regulated power supply as an example, the output voltage will be fed back to the comparator inside the IC. The comparator compares the feedback voltage with a reference voltage. If the feedback voltage is higher than the reference voltage, the IC will adjust the duty cycle of the PWM signal to reduce the output voltage; on the contrary, if the feedback voltage is lower than the reference voltage, the IC will increase the duty cycle to increase the output voltage. In this way, it can be ensured that the output voltage is always kept near a set stable value.
Application fields
- Consumer electronics field:
  - In mobile phones, tablets, laptops, digital cameras and other devices, power driver ICs are everywhere. They provide stable power support for various links such as battery charging, screen display, and chip operation of these devices. For example, in a mobile phone, the power driver IC can control the charging process to ensure safe and fast charging of the battery; at the same time, it provides suitable voltage and current for different parts such as the processor, display screen, and camera of the mobile phone.
- Industrial field:
  - Industrial automation equipment, robots, industrial power supplies, etc. all need power driver ICs. In industrial automation equipment, power driver ICs can provide stable power for motor drives, sensor power supplies, etc., ensuring the normal operation of equipment. For example, in the motor drive system on an automated production line, the power driver IC can provide the motor with appropriate voltage and current according to the control signal to drive the motor to operate as required.
- Automotive field:
  - Electronic control units (ECUs), in-vehicle entertainment systems, and power systems of electric vehicles in the automotive electronics system all require power driver ICs. In electric vehicles, power driver ICs are used in battery management systems to control the charging and discharging processes of batteries and provide suitable power for motor drive systems to ensure the safety and efficient operation of vehicles.
- Lighting field:
  - Whether it is traditional fluorescent lighting or modern LED lighting, power driver ICs play a key role. For LED lighting, the power driver IC can realize constant current driving of LEDs to ensure the luminous efficiency and lifespan of LEDs. For example, in street lighting systems, power driver ICs can control the brightness and switching time of LED street lights according to factors such as ambient light intensity and time.