Research And Design Of 16-Bit Constant Current LED Driver Control Chip Based On CMOS Process

With the rapid growth of electronic technology and the development of science and technology, continuous development and innovation of electronic products, LED display as a high-tech electronics has attracted much attention They are widely used in finance, telecommunications, post, gymnasium, traffic and other fields. At the same time, people hope that the LED display could become high uniformity, big size, long life time, and high display quality. Universal power driver chips in the market are no longer able to suit the people's application requirements. Therefore, the current research focus has shifted to multi-channel, highly accurate LED output current special driver chip. Luminance is mainly controlled by LED driving current, so a constant-current source is the best LEDs drive.This thesis researches and designs a 16-bit constant current LED driver CMOS control chip. The design requirement of this chip's input voltage ranged on 3.3V to 5.5V. The output current is accurate, it's range on 20 to 90 of each channel and this chip's output current can be adjusted. The data shift clock frequency can reach 25MHz, also satisfies the system requirement of high data transmission. This thesis also introduces the modules including bandgap voltage reference which based on chopper technology, improved ring oscillator, current feedback constant current driver, digital control circuit, ESD protection circuit and so on.Use the Cadence software with the 0.5um csmc DPTM Mixed Signal CMOS process complete the whole chip's simulation. Simulate the each module circuit, and on this basis, the article completed the overall circuit simulation and test analysis. And the effective area of the chip is 1561*989um2. Adjust the external resistance in the range on 200O to 1KO, the maximum output current swing of 90mA. Output current response time is less than 200ns; the results from simulation show that the 16-bit constant current LED driver CMOS control chip designed in this article satisfies the predefined requirements.