With more and more mobile phones and other terminals on the market that support wireless charging, the demand for wireless charging is constantly released and gradually penetrates into the automotive front-loading market. Nanxin Semiconductor, which has been deeply involved in the field of charging, while continuing to increase investment in wireless charging research and development, has recently launched three automotive-grade chips SC8701Q/SC8101Q/SC5003Q, covering power from 15W to 50W, escorting the localization of vehicle wireless charging solutions.
Car wireless charging Block Diagram
The schematic diagram of in-vehicle wireless charging is shown in the figure, which consists of a DCDC with a wide voltage input, a wireless charging transmitter (integrated Power Stage), a general-purpose MCU, and a high-voltage LDO. The wireless charging transmitter sends the IDM/VDM/ISNS signal to the MCU, which adjusts the voltage of the DCDC through PWM or I2C on the one hand, and the operating duty cycle of the internal Power Stage of the transmitter according to the power required by the device, thereby adjusting the output power of the transmitter. Here the LDO is used to power the MCU, which is the optional option, or it can be implemented by the integrated buck inside the wireless charging transmitter.
At present, the vehicle wireless charging power level is mainly divided into 15W and 40W/50W, and the ratio is about 3:1. 15W power level According to different applications, the pre-DCDC can be divided into two topologies: buck and buck-boost.
The lead-acid battery voltage for passenger cars is typically 12V, but it fluctuates from 9V to 16V, so it can be divided into three scenarios:
(1) In the 15W wireless charging application of some models, when the battery voltage is lower than 12V, the system will reduce the power of the wireless charging module, so the previous DCDC can be achieved with a buck converter.
(2) In the 15W wireless charging application of most models, the entire battery voltage fluctuation process is required to have a 15W power output, at which time the front DCDC needs to be achieved with a buck-boost chip.
(3) In 40W/50W wireless charging applications, the voltage at the transmitter needs to reach 20V, so a buck-boost chip is also required to achieve it.
With its deep accumulation in power charging management, Nanxin Semiconductor has recently been launched
SC5003Q(20V Wireless Power Transmitter)
SC8101Q(32V/5A buck-converter)
SC8701Q(36V buck-boost controller)
to cover this piece of the market. Depending on the power class and supported battery voltage range, we can roughly divide into three categories:
#1 Automotive Grade High Efficiency Synchronous Buck Converter - SC8101Q
The SC8101Q is a vehicle-grade 32V/5A synchronous buck converter that supports the highest absolute withstand voltage of 40V. The integrated 45mΩ/35mΩ up and down switch tubes and 90uA quiescent current allow for ideal conversion efficiency over the entire load range. The Flip-Chip QFN package can eliminate the oscillation caused by the internal Bonding Wire on the switch node, resulting in better EMI performance.
#2 Auto spec-level integrated full-bridge Power Stage's high-efficiency wireless TX – SC5003Q
The SC5003Q is ACC's automotive-grade, highly integrated wireless power transmitter analog front end that contains all the analog components needed to achieve a WPC-compatible transmitter. At the same time, the SC5003Q integrates a high-precision Q value detection function, which can easily realize the foreign object detection function, create a high-performance wireless power transmitter together with the transmitter controller, and comply with WPC V1.2.4 EPP and BPP specifications. The wireless power transmitter analog front end is AEC-Q100 Grade1 certified.
(SC8101Q+SC5003Q Wireless Charging Solution Demo)
#3 Vehicle Grade High Efficiency Synchronous Boost Controller - SC8701Q
SC8701Q is a synchronous 4 power tube buck-boost controller, the output voltage can be higher than, equal to or lower than the input voltage, ultra-high conversion efficiency can effectively improve the thermal performance of the system. The SC8701Q supports an ultra-wide range of input and output voltages from 2.7V to 36V and output voltages from 2V to 36V, and uses a 10V/2A MOSFET driver to maximize the use of external MOSFETs for high efficiency. The SC8701Q supports input current limit, output current limit, and overtemperature protection to ensure that the chip can operate normally under various abnormal conditions. The OUTPUT voltage and input and output current limit of the SC8701Q can be dynamically adjusted by PWM signal, and the switching frequency is adjustable from 200KHz to 600KHz, which allows customers to flexibly design according to system requirements.
In addition to wireless charging applications, the SC8701Q can also be used to power the Camera in 60W wired fast charging and ECUs in ADAS's 360° surround view system. The synchronous buck-boost controller is AEC-Q100 Grade1 certified.
(SC8701Q+SC5003Q+NXP WCT2013A Wireless Charging Solution Demo)