1. Founded in 2003, Xinhai Technology has always focused on the research and development and design of high-performance MCU, measurement algorithm and one-stop solution of the Internet of Things. It is not only an integrated circuit design enterprise with both analog signal chain and MCU dual platform drivers, but also one of the few integrated circuit design enterprises with artificial intelligence Internet of Things overall solution in China.
2, the three leading stocks of domestic chips are: Zhaoyi Innovation, Jiangfeng Electronics, North China Chuang. Zhaoyi Innovation Zhaoyi Innovation ranks among the world's Norflash citiesTop three in the market, and with the withdrawal of Japanese and American companies, the market share continues to increase; Storage prices are soaring, and the company's profitability is booming. The company builds IDM storage industry chain.
4, mainly involved in video surveillance chips, and security leader Hikvision is closely related, in recent years, the security IPC chip market has developed rapidly, operating income and net profit growth is larger, the major brokerages dimension> According to the number of phases to distinguish, there are two phases, three phases, five phases according to the drive mode to distinguish, there are two kinds of single-pole drive and bipolar drive, most of the chips now commonly used are bipolar drive, suitable for hybrid stepper motor drive.
Core components of the drive circuit First, the power input line provides a stable and rated voltage to the motor, and is tightly connected to a specially designed drive board. The control signal line delivers the PWM (pulse width modulation) signal generated by the microcontroller.It is the director of motor speed and direction adjustment.
Detailed design steps We provide a practical case of constructing drive circuits with 240 series and 32 four-way and non-gates to realize the parallel design of two H-bridges. The inverter uses CMOS output to drive the NFET on the lower side, ensuring smooth operation at 5V voltage.
The magic of PWM signals: high levels drive current flow, low levels form a self-inductive electromotive force loop, like the rhythm of music, precisely control the rhythm of the motor. In the hardware design, the STM32 skillfully directs the construction of the H bridge, and the upper bridge arm requires additionalBooster drive, bootstrap circuit becomes the key.
Power of the H-bridge The essence of the H-bridge drive is the clever layout of the four switches (bridge arms), which precisely control the forward and reverse rotation of the motor, preventing the risk of short circuits. Through modulationThe state of the entire MOS tube (metal oxide semiconductor field effect tube) can achieve accurate switching of the motor, ensuring that the motor operates within a safe current range.
H bridge usually needs two synchronous positive and negative signals to drive the following figure, you can make DC motor stop, forward turn, reverse three actions, of course, A B input signal can also be replaced by a single signal, but the action is only two.
Driver chip L298 is a special chip to drive two-phase and four-phase stepper motors, we use its internal bridge circuit to drive DC motors, this method has a series of advantages.
To make the motor run, a pair of triodes on the diagonal must be switched on. Depending on the conduction of the different triode pairs, the current may flow through the motor from left to right or from right to left, thus controlling the steering of the motor. Figure 12 H-bridge drive circuit In order for the motor to operate, it is necessary to make a pair of transistors on the diagonal.
1, need to add more compression and processing technology, chipBarriers to entry will rise. Due to the high entry threshold of OLED driver chips, the global driver chip market shows a high concentration. 2, as one of the core components of the OLED screen, due to the limitations of the OLED panel IC chip, most OLED driver chips need to be customized according to the screen, so it is difficult for foundries to mass produce.
3, now Huawei enters this field, indicating that the monopoly position of Samsung and LG is about to be broken. Moreover, Huawei's driver chips can be completely produced in China and will not be cut off like Huawei Hisilicon processorsFor the impact. It can be said that this is another major breakthrough achievement after Huawei's Kirin platform processor. 4, OLED driver chips are facing a tide of out-of-stock price increases, following the price rise in the first quarter, the price of OLED driver chips rose by 20% in the second quarter of 2021. In this context, the successful mass production of this chip will ensure the supply of essential components for Huawei's OLED screen products.
5, this is also following Samsung, TSMC, Intel, AMD, Huawei's other two key suppliers to the United States "release". Samsung Electronics news, Samsung for nowSupplies to Huawei have indeed resumed, but only OLED panels can be provided, and semiconductor chips used to drive panels are not allowed to be provided.