1, the LED driver chip, in fact, is a PWM control chip, after the normal operation of the circuit, through the current detection resistance behind the detection of the LED current and the voltage feedback to the chip, control the internal PWM duty cycle, in order to adapt to the LED's own characteristics caused by changes in the current, voltage fluctuations, so that the LED current remains constant.
2. This is a BUCK circuit. The IC is a power management IC, but definitely not the 3842 or 555 that the others answered. 2 pin Rs, 3 pin GND, 4 called drive, 5-pin compensation or other, 6-pin VCC similar to HV9910. Copy the board, 3W power can be simpler than this with IW1706, and the output open circuit voltage is low.
3, LED driver chip can be divided into general chip and special chip two. The so-called universal chip, the chip itself is not specifically designed for LED, but some logic chips with some logic functions of the LED display (such as series-and-shift registers). The special chip refers to the driver chip designed specifically for the LED display according to the LED luminous characteristics.
4, to 2 feet green lightBlue LED chip, 3 to 4 pins for red LED chip, 5 to 6 pins for green light/blue LED chip. Red light has the smallest VF, and the current limiting resistance is relatively larger, and green light and blue light VF are almost the same, and the current limiting resistance is the same.
5, PNP triode driver is recommended to use 8550 PNP triode to do the driver, 555 tripin triode B, E in parallel 43 leds (each LED plus a small current limiting resistance). The size of the resistance should be determined according to the LED.
6, COB and other leds are not fundamentally different, but n led coresid=' What is the principle of led driver chip '> What is the principle of led driver chip
LED (LightEmittingDiode) driver chip is a kind of electronic device used to drive LED lights. Its working principle is to convert the input current into the current and voltage suitable for the work of LED lights. Specifically, the LED driver chip is usually composed of two parts: the power supply part and the control part.
Its working principle is to use the control circuit inside the circuit to control the size of the output current, so that the LED lamp produces different brightness output. LEDThe circuit design of the driver chip is generally composed of the following parts: Input voltage control: This part is responsible for stabilizing the input voltage and ensuring that the driver chip can work normally.
led driver chip principle LED control card built-in high-performance single-chip LED driver chip, the controller through the internal control program to the LED driver chip to send control signals and data, LED driver chip according to the control signal and data requirements, produce the corresponding action, so as to achieve separate control of each red, green, blue LED.
The working principle of led driver ic: the chip contains constant current generationThe circuit can set the output constant current value through the external resistor. The switch time of the output channel can be controlled through the enable side of the chip, and the switching frequency is up to one megahertz (1mhz). The current output response is extremely fast, supporting applications with high color level changes and high picture refresh rate.
How the pt4455 works The PT4455 is a high-performance LED driver chip that provides up to 2A output current and can drive up to 8 leds. It uses advanced PWM technology, which can provide higher accuracy and lower noise.
At present, LED display special driver chip manufacturers are mainly TOSHIBA (Toshiba), TI (Texas Instruments), SONY (SONY), MBI{accumulation technology}, SITI (point crystal technology) and so on. In the domestic LED display industry, these chips have applications. TOSHIBA products are more cost-effective and have the highest market share in the domestic market.
LED control IC is mainly used in full color gradient dimming control fence lights, LED Decorative lights, landscape lights and other RGB full-color light source lamps synchronous scanning, full-color color control.
General purpose chips are generally used for low-end LED display products, such as indoor single and two-color LED display screens. The most commonly used general-purpose chip is the 74HC595, which has an 8-bit latch, serial-and-shift register, and three-state output. The maximum output current of each channel is 35 mA (not constant current). General IC manufacturers can produce such chips.
Commonly used LED drivers are determined according to different W numbers, and now there are a lot of driver schemes, according to customersThe requirements will also define a number of different driver ics.
OCP8121 is a single-channel high-power LED driver control chip, mainly used in large screen LCD TV backlight LED driver. Main features: Input voltage: 0V~20V, adjustable; Current: 10mA. Package: SOP-16L lead-free package. Operating temperature range ‐ ℃ ~ 85℃. Please accept it.
Backlight chip is a type of backlight module commonly used in displayElectronic components. How to properly disconnect the protection circuit to ensure its normal operation is always an important problem. This paper will introduce the method of disconnecting 9902 backlight chip protection circuit from three aspects. First of all, understanding the 9902 backlight chip protection circuit is the key.
SIRF. In the promotion of HaoZhixin navigation, we learned that the chip model of this product is SIRF, which is a new invention, and HaoZhixin Navigation is suitable for the navigation device of Audi cars.
TOSHIBA: Toshiba Semiconductor is a major supplier of leds for automotive, especially instrument panel backlights, carsRadio, navigation system, climate control. The technology used is InGaAlP, with wavelengths ranging from 560nm (puregreen) to 630nm (red).