THine Value What is an LED Driver? A Detailed Explanation of Its Role: Expanding the Lineup with User-Friendly ラスベガスのカジノD Drivers for Decorative Lighting
2024.09.25
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An LED driver is a driving circuit that powers light-emitting diodes (LEDs). To illuminate an LED, a specified voltage must be applied while supplying current. If the supplied current remains constant, ラスベガスのカジノrightness (luminance) of the LED stays stable without any fluctuations. Therefore, the role of an LED driver is to supply a steady voltage/current to the LED.
Today, LED drivers are being manufactured by numerous semiconductor companies, resulting in a vast array of products. However, when classified by application, they fall into two main categories: for "lighting" and for "decoration."
Our company (THine Electronics) is one of the semiconductor manufacturers producing LED drivers. The distinguishing feature of our products is that they are all designed for decorative lighting applications (Fig. 1). Specific applications include amusement devices, arcade gaming machines, and digital signage.
Today, LED drivers are being manufactured by numerous semiconductor companies, resulting in a vast array of products. However, when classified by application, they fall into two main categories: for "lighting" and for "decoration."
Our company (THine Electronics) is one of the semiconductor manufacturers producing LED drivers. The distinguishing feature of our products is that they are all designed for decorative lighting applications (Fig. 1). Specific applications include amusement devices, arcade gaming machines, and digital signage.
Fig. 1 Decorative LED Driver
Power Requirements for Lighting Applications
So, what performance and functions are required for LED drivers used in lighting and decorative applications? Let us take a closer look.
As the name suggests, LED drivers for lighting are designed for lighting fixtures and equipment, primarily intended to drive white LEDs. Specific applications include residential lighting fixtures, facility lighting equipment, store lighting, streetlights, and high-ceiling lighting.
One of the key requirements for LED drivers used in lighting applications is power. To achieve bright (high-luminance) lighting fixtures, a larger current must be supplied to the LEDs. For this reason, products capable of supplying drive currents as high as several amperes have been introduced into the market for LED drivers for lighting applications.
In addition, dimming functionality is essential. Dimming refers to the ability to adjust ラスベガスのカジノrightness of the LEDs. For instance, turning a knob installed on a wall or using a dedicated remote control allows users to adjust ラスベガスのカジノrightness of the LEDs gradually. There are two main methods for achieving dimming. One is analog dimming, which adjusts the LED brightness by changing the amount of current supplied to the LED. The other is pulse width modulation (PWM) dimming, which controls ラスベガスのカジノrightness by adjusting the LED's on-time and off-time within a given period. Increasing the on-time brightness of the LED while shortening it dims the LED. The PWM signal determines the length of the on and off periods, and brightness is controlled by varying the duty cycle (the ratio of on-time to off-time) of the PWM signal.
As the name suggests, LED drivers for lighting are designed for lighting fixtures and equipment, primarily intended to drive white LEDs. Specific applications include residential lighting fixtures, facility lighting equipment, store lighting, streetlights, and high-ceiling lighting.
One of the key requirements for LED drivers used in lighting applications is power. To achieve bright (high-luminance) lighting fixtures, a larger current must be supplied to the LEDs. For this reason, products capable of supplying drive currents as high as several amperes have been introduced into the market for LED drivers for lighting applications.
In addition, dimming functionality is essential. Dimming refers to the ability to adjust ラスベガスのカジノrightness of the LEDs. For instance, turning a knob installed on a wall or using a dedicated remote control allows users to adjust ラスベガスのカジノrightness of the LEDs gradually. There are two main methods for achieving dimming. One is analog dimming, which adjusts the LED brightness by changing the amount of current supplied to the LED. The other is pulse width modulation (PWM) dimming, which controls ラスベガスのカジノrightness by adjusting the LED's on-time and off-time within a given period. Increasing the on-time brightness of the LED while shortening it dims the LED. The PWM signal determines the length of the on and off periods, and brightness is controlled by varying the duty cycle (the ratio of on-time to off-time) of the PWM signal.
High Performance for Decorative Lighting Applications
On the other hand, LED drivers for decorative lighting are designed to drive ラスベガスのカジノDs, which contain three types of LEDs—red (R), green (G), and blue (B)—in a single package. By finely controlling the brightness of each of the ラスベガスのカジノDs, various colors can be expressed. This capability is used to display full-color images and create complex lighting effects. Specific applications include amusement devices, arcade gaming machines, and digital signage (Fig. 2).
A key feature required for LED drivers used in decorative lighting is the ability to create diverse real-time effects via serial communication with addressing. To achieve the desired displays and colors, it is necessary to supply the appropriate current to each ラスベガスのカジノD. PWM dimming functionality is used to adjust the current supplied to the LEDs. This PWM dimming function requires a wide dynamic range (the ratio of maximum to minimum supply current), fine resolution, and high precision in setting values.
For example, an 8-bit resolution, or 256 levels, is often required. If the brightness of each ラスベガスのカジノD can be adjusted in 256 steps, a full-color display of 256 x 256 x 256 = approximately 16.77 million colors is possible (Fig. 3). Of course, depending on the application, lower resolution than 8-bit may also be sufficient.
Fig. 2 Conceptual Image of Using ラスベガスのカジノDs in Digital Signage
A key feature required for LED drivers used in decorative lighting is the ability to create diverse real-time effects via serial communication with addressing. To achieve the desired displays and colors, it is necessary to supply the appropriate current to each ラスベガスのカジノD. PWM dimming functionality is used to adjust the current supplied to the LEDs. This PWM dimming function requires a wide dynamic range (the ratio of maximum to minimum supply current), fine resolution, and high precision in setting values.
For example, an 8-bit resolution, or 256 levels, is often required. If the brightness of each ラスベガスのカジノD can be adjusted in 256 steps, a full-color display of 256 x 256 x 256 = approximately 16.77 million colors is possible (Fig. 3). Of course, depending on the application, lower resolution than 8-bit may also be sufficient.
Fig. 3 ラスベガスのカジノDs for Full Color Displays
Existing Products (THL3512/THL3514) Use LVDS Interface
As mentioned earlier, we have already commercialized LED drivers for decorative lighting designed to drive ラスベガスのカジノDs.
These LED drivers are used in combination with a CPU (Fig. 4). The CPU outputs data signals and clock signals that specify the color to be displayed to the LED driver via an interface (e.g., a 3-wire serial interface). The LED driver processes these signals internally and generates PWM signals that control the brightness of each ラスベガスのカジノD. These PWM signals are supplied to the ラスベガスのカジノDs via output channels, causing the LEDs to emit light and display the specified color.
However, amusement devices, arcade gaming machines, and digital signage typically have large enclosures and use multiple ラスベガスのカジノDs. Even when multiple ラスベガスのカジノDs are used, only one ラスベガスのカジノD is directly connected to the CPU. The remaining ラスベガスのカジノDs are connected in a cascade or multi-drop configuration (Fig. 5).
The existing THL3512/THL3514 featured an interface designed for cascade or multi-drop connections. Specifically, they used a two-pair LVDS interface (2-wire serial LVDS). Since LVDS uses a differential transmission method, it has the advantage of being highly resistant to common-mode noise.
These LED drivers are used in combination with a CPU (Fig. 4). The CPU outputs data signals and clock signals that specify the color to be displayed to the LED driver via an interface (e.g., a 3-wire serial interface). The LED driver processes these signals internally and generates PWM signals that control the brightness of each ラスベガスのカジノD. These PWM signals are supplied to the ラスベガスのカジノDs via output channels, causing the LEDs to emit light and display the specified color.
Fig. 4 Example of Decorative LED Driver Connection
However, amusement devices, arcade gaming machines, and digital signage typically have large enclosures and use multiple ラスベガスのカジノDs. Even when multiple ラスベガスのカジノDs are used, only one ラスベガスのカジノD is directly connected to the CPU. The remaining ラスベガスのカジノDs are connected in a cascade or multi-drop configuration (Fig. 5).
Fig. 5 Cascade and Multi-drop Connections
The existing THL3512/THL3514 featured an interface designed for cascade or multi-drop connections. Specifically, they used a two-pair LVDS interface (2-wire serial LVDS). Since LVDS uses a differential transmission method, it has the advantage of being highly resistant to common-mode noise.
Expanding the Product Lineup (THL3526)
However, there is also a disadvantage to the LVDS interface. Due to its differential transmission method, the number of wires increases compared to single-ended transmission. "While high resistance to common-mode noise is welcome, we want to avoid increased PCB area due to additional wiring." Because of such design considerations, some electronics manufacturers hesitated to adopt LED driers with LVDS interfaces.
In response to this feedback, we have expanded our product lineup of LED drivers for decorative lighting. The newly developed product is the THL3526 (Table 1), which does not use the LVDS interface. For connecting LED drivers, the THL3526 allows the selection of a 3-wire serial interface (SPI), 2-wire serial interface (SPI), or I2C interface via terminal settings. Since all of these use single-ended transmission methods, the number of wires does not increase. This makes for an ideal product for electronics manufacturers seeking to avoid increased PCB space.
In response to this feedback, we have expanded our product lineup of LED drivers for decorative lighting. The newly developed product is the THL3526 (Table 1), which does not use the LVDS interface. For connecting LED drivers, the THL3526 allows the selection of a 3-wire serial interface (SPI), 2-wire serial interface (SPI), or I2C interface via terminal settings. Since all of these use single-ended transmission methods, the number of wires does not increase. This makes for an ideal product for electronics manufacturers seeking to avoid increased PCB space.
Table 1 Comparison of Our Existing Products with the New Product
Supports Constant Voltage and Constant Current Driving
Additionally, the THL3526 includes three features designed to improve the usability of LED drivers for electronics manufacturers.
The first feature, continuing from our previous products, is the integration of a buffer circuit into the interface for connecting LED drivers (Fig. 6). This buffer circuit functions as a repeater or re-driver. In other words, it receives the single-ended signal (TTL signal) flowing through the interface, reshapes the signal waveform, and retransmits it. As a result, the transmission distance of the interface can be extended. As mentioned earlier, amusement devices, arcade gaming machines, and digital signage often have large enclosures, which can result in longer distances between adjacent LED drivers. The integration of ラスベガスのカジノuffer circuit in this product addresses such cases, allowing for extended distances between drivers.
The second feature is the ability of a single LED driver to support both constant current driving and constant voltage driving. By configuring the terminals, either constant current or constant voltage driving can be selected. ラスベガスのカジノenefit of this feature is that it simplifies procurement and inventory management. There is no longer a need to procure two different types of drivers—one for constant current and one for constant voltage—allowing inventory management to be consolidated into one type.
The third feature is the enhanced electrostatic discharge (ESD) tolerance. This was achieved by optimizing the circuit design of the LED driver. Our internal testing confirmed that the device withstands 8 kV of ESD in the human body model (HBM). This surpasses many competitors' products, which typically offer 2 kV.
The new product is packaged in a 48-terminal QFN with a mounting area of 7 mm x 7 mm. The maximum drive current is 40 mA in constant current mode and 80 mA in constant voltage mode. ラスベガスのカジノrightness adjustment supports up to 256 levels, and the supply voltage range is 4.5 V to 5.5 V.
With the launch of this new product, our lineup of decorative LED drivers has been expanded. This allows manufacturers to select the most suitable LED driver according to the design philosophy of their amusement devices or arcade gaming machines.
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The first feature, continuing from our previous products, is the integration of a buffer circuit into the interface for connecting LED drivers (Fig. 6). This buffer circuit functions as a repeater or re-driver. In other words, it receives the single-ended signal (TTL signal) flowing through the interface, reshapes the signal waveform, and retransmits it. As a result, the transmission distance of the interface can be extended. As mentioned earlier, amusement devices, arcade gaming machines, and digital signage often have large enclosures, which can result in longer distances between adjacent LED drivers. The integration of ラスベガスのカジノuffer circuit in this product addresses such cases, allowing for extended distances between drivers.
Fig. 6 Internal Block Diagram for THL3526
The second feature is the ability of a single LED driver to support both constant current driving and constant voltage driving. By configuring the terminals, either constant current or constant voltage driving can be selected. ラスベガスのカジノenefit of this feature is that it simplifies procurement and inventory management. There is no longer a need to procure two different types of drivers—one for constant current and one for constant voltage—allowing inventory management to be consolidated into one type.
The third feature is the enhanced electrostatic discharge (ESD) tolerance. This was achieved by optimizing the circuit design of the LED driver. Our internal testing confirmed that the device withstands 8 kV of ESD in the human body model (HBM). This surpasses many competitors' products, which typically offer 2 kV.
The new product is packaged in a 48-terminal QFN with a mounting area of 7 mm x 7 mm. The maximum drive current is 40 mA in constant current mode and 80 mA in constant voltage mode. ラスベガスのカジノrightness adjustment supports up to 256 levels, and the supply voltage range is 4.5 V to 5.5 V.
With the launch of this new product, our lineup of decorative LED drivers has been expanded. This allows manufacturers to select the most suitable LED driver according to the design philosophy of their amusement devices or arcade gaming machines.
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