What Is a Gate Driver IC?
A gate driver IC is an integrated circuit (IC) that combines circuits for driving and controlling liquid crystal displays, motors, and other devices.
Designing such control circuits with discrete components is problematic because the overall circuit design, including the control circuits and their surroundings, is complex and prone to overcurrent and overheating. Therefore, by integrating a control circuit with the same functions into the driver IC, it is possible to simplify the overall circuit design, reduce the size of the entire circuit, and save power.
In addition to avoiding the risk of overcurrent and overheating, the advantage of reducing the power consumption of the entire circuit is that the usable time of battery-driven products can be extended. Also, assuming that the area that can be used for the control circuit is about the same, using an IC can realize a larger-scale and more complicated circuit.
In particular, LCD gate driver ICs have advanced along with the miniaturization of electronic devices (miniaturization of individual circuit elements), and with the high resolution and power saving requirements of displays.
Uses of Gate Driver ICs
Gate driver ICs are used as control circuits in a wide range of fields, including home appliances, communications equipment, transportation equipment, and industrial equipment.
The following is a list of major gate driver ICs and their applications.
1. LCD Drivers
LCD gate driver ICs, called LCD drivers, are used to control the displays of PCs, smartphones, and other devices (LCD: Liquid Crystal Display). is the development of advanced functions for the entire device, such as the incorporation of memory to store the display information.
2. Motor Drivers
Motor gate driver ICs are widely used to control motors in products such as home appliances, vending machines, robot arms, etc. PWM (Pulse Width Modulation) control enables higher efficiency.
3. LED Drivers
LED light gate driver ICs are used to control the light emission of products that use LEDs, such as automotive LEDs, lighting LEDs, and LED displays. Compared to conventional products, it has the great advantage of being able to reduce power consumption. By using PWM control, it is possible to achieve a dimming function without changing the color of the LED lighting equipment.
4. Gate Driver
Gate driver ICs are used in industrial robots, power tools, electric bikes, cooling fans, and drones. In recent years, products that integrate a microcontroller for control and a gate driver on a single chip have emerged. These are called “smart gate drivers,” and they enable miniaturization of the entire circuit and higher functionality.
Technologies for miniaturization, power saving, and higher efficiency are being recognized as major issues in the overall development of electrical devices.
Principle of Gate Driver ICs
In some cases, it is possible to design control circuits with discrete components without using gate driver ICs.
For example, if a motor driver is not used, the circuit configuration becomes more complex because four MOS-FETs are used. On the other hand, since the motor driver IC incorporates MOS-FETs for control, it is possible to simplify the overall circuit configuration, including the motor and control circuit.
LCDs have signal lines and scanning lines wired in a matrix. Pixels exist at the intersections of the two lines, and color coding is performed by finely adjusting the voltage values applied to the pixels. Both signal lines and scanning lines require control circuits, but designing with discrete components is impractical due to space constraints and the need for increasingly complex and large-scale control circuits to accommodate higher LCD resolutions.
Therefore, actual products use LCD driver LSIs (an advanced type of driver IC) as control circuits.