Air conditioning is an indispensable configuration to meet the comfort requirements of the car. It is used for interior cooling, heating, ventilation, and a comfortable driving environment is also related to driving safety. The automatic air conditioner is more convenient than the traditional manual air conditioner, and can automatically detect and adjust according to the temperature set by the user, so that the temperature and humidity in the vehicle are within the set range. Moreover, automatic air conditioning also helps to save energy and reduce fuel economy. This article refers to the address: http:// Typical power supply structure for automotive air conditioners In general, the car voltage is divided into 24V system and 12V system: 24V power supply can be powered by high-power TVS (transient voltage suppressor), then by low-dropout regulator (LDO) to 5V, while powering the motor driver It can also be reduced to 12V by a higher cost DC-DC buck, then from LDO to 5V, while powering the motor driver; 12V power supply through the LDO for microcontroller, sensor and other components, while directly DC / step Power is supplied to the motor driver such as the motor. Figure 1. Typical power supply structure for automotive air conditioning If you use a 24V power supply system, you need to consider high-voltage products, while taking into account thermal management, power efficiency and cost control; if you use a 12V power supply system, you need to consider factors such as cost, quiescent current (Iq) and packaging. ON Semiconductor offers a rich lineup of LDOs for automotive air conditioning systems, with standard static power series (Iq > 100uA) such as NCV4264-2, NCV4266-2, and low static power series (Iq < 100uA) such as NCV8501 and NCV8502, very low Static power series (Iq < 50uA) such as NCV8664, NCV8660, ultra-low static power series (Iq < 33uA) such as NCV8768, NCV8769, meet the different needs of the design. ON Semiconductor also offers the voltage follower NCV8184, which provides an adjustable buffered output voltage that closely matches the reference input voltage (±3mV accuracy). The device's output current capability is 70mA, quiescent current is only 70uA, and when the current is 50mA, the typical voltage drop is only 0.35V, in SOIC-8 package. drive Damper actuator drive DC motors, unipolar stepper motors, and bipolar stepper motors are three typical structures for automotive air-conditioning damper actuators. The DC motor damper actuator includes a DC motor and a position sensor. A complete H-bridge (composed of 2 high-side switches and 2 low-side switches) is required to control the forward and reverse rotation of the motor. The position sensor can monitor the position of the damper in real time to realize closed-loop control. The control of the unipolar stepping motor only needs 4 high sides or 4 low side drives. Due to the characteristics of the stepping motor itself, the number of steps can be counted. To know the position of the damper; the bipolar stepper motor only needs two sets of coils, and its drive requires two H-bridges (composed of four high-side switches and four low-side switches) to control the two coils, and unipolar The stepper motor is similar, and the current position of the damper can be known by counting the number of steps. Figure 2. Damper actuator motor structure and drive type The normal operating current of the DC motor damper actuator is about 100 mA, and the stall current is less than 450 mA. The H-bridge drive is required to change the running direction, and a fault diagnosis report and sufficient protection functions are provided. ON Semiconductor's NCV77XX series fully meets these requirements and can operate in forward, reverse, braking and high impedance states. Take the six-way half-bridge driver NCV7718 as an example. Six PMOSs are used as high-side drivers, six NMOSs are used as low-side drivers, high and low sides are connected inside the chip, and H half-bridges are used as outputs to provide 0.55A continuous drive current. Diode, on-resistance typical and maximum are 1Ω and 2.25Ω, controlled by 16-bit SPI interface, low power consumption (maximum current consumption is only 5Ua), providing drive state, low load protection, overcurrent, overtemperature and temperature Diagnostic reports such as warnings and integration of a range of protection features such as overvoltage/undervoltage protection, overcurrent shutdown, overtemperature protection, etc., in SSOP-24/SSOP24-EP package. In addition, depending on the output requirements, you can choose ON Semiconductor's 8-way half-bridge driver NCV7719 or 10-way half-bridge driver NCV7720. ON Semiconductor also offers a six-way half-bridge driver NCV7728 with independent diagnostics. The device has a peak current of 0.55A. The typical and maximum on-resistance are 1Ω and 2Ω, respectively. The interface is compatible with 3.3V/5V microcontrollers in sleep mode. Ultra-low static power consumption, controlled by 16-bit SPI interface (baud rate 5 MHz, compatible with daisy-chain communication), integrated protection features such as freewheeling protection, overcurrent protection, open circuit detection, thermal shutdown and overtemperature alarm . Figure 3. Typical application example for a 6-way half-bridge driver NCV7728 with independent diagnostics In the stepper motor damper actuator, each motor needs 4 drives, and the maximum working current is less than 300mA. It can be directly controlled or remotely controlled via LIN bus. ON Semiconductor's unipolar stepper motor drivers for automotive air conditioners are the NCV7608 and NCV7240. The NCV7608 is an 8-channel high- and low-side configurable driver that provides 350mA of drive current per channel. It provides comprehensive protection and is certified in AOC-Q101 in a SOIC28 package. The NCV7420 is an 8-channel low-side driver that provides 600mA of drive current per channel. Through 16-bit SPI interface control, it provides complete diagnostic and protection functions such as open circuit diagnosis, overload protection and over temperature protection. It is packaged in SSOP24 and certified by AEC-Q100. ON Semiconductor's bipolar stepper motor drivers for automotive air conditioners include the AMIS30730 and NCV70501, both of which have a drive current of 300mA. The AMIS30730 uses a LIN interface with MCU, ROM, RAM and EEPROM; the NCV70501 uses an SPI interface. 2. High/low side drive SmartFETs are used for control of external loads (such as relays in central electrical boxes) and can be used as high-side or low-side drives that require additional protection features such as short-circuit protection, thermal shutdown, overvoltage protection, and logic Flat control and ESD protection. ON Semiconductor's NCV8452 is a high-side SmartFET with an on-resistance of 200mΩ, an overvoltage protection rating of 41V, and an output current limit of 1A. It integrates a wide range of protection features such as short-circuit protection, overload protection, and Temperature shutdown and auto-restart, internal clamp diode overvoltage protection, ESD protection and logic level control, etc., junction temperature -40 ~ 150 °C. ON Semiconductor's high-/low-side smart drive devices include NCV8440, NCV8450, and NCV8401/2/3/5/6, which provide different clamping voltages, on-resistance, and output current parameters. 3. Blower drive Blowers fall into two broad categories: brushed DC motors and brushless DC motors (BLDC). The brushed DC motor has a maximum operating current of 30A and uses PWM control with power MOSFETs. The BLDC motor requires a pre-driver and power MOSFET. ON Semiconductor offers N-channel power MOSFETs for brushed DC motors and BLDC drives as shown in Table 1, as well as three-phase pre-drivers for BLDC motors such as the LV8907UW and MC33033/5. To help engineers simplify design and save space, ON Semiconductor also offers the STK984-xxx series of intelligent power modules with integrated pre-drivers and power MOSFETs, an integrated motor-driven algorithm, six MOSFETs and driver circuits, via PWM or voltage regulation. The OTP register is provided for motor parameter configuration, modularization for PCB-free design, and integrated protection features such as overcurrent protection, overtemperature protection, and overvoltage/undervoltage protection. Table 1. N-Channel Power MOSFETs for Blower Drives Figure 4. Block diagram of the intelligent power module STK 984-XXX 4. LED driver - CCR ON Semiconductor's constant current regulator (CCR) is used to drive LEDs in automotive air conditioning systems. These devices have built-in LED thermal protection that can replace low-cost LDOs and reduce system cost. Since there is no EMI (electromagnetic interference), it is suitable for A low-noise system that provides a constant current over a wide input voltage range to suppress LED brightness variations due to voltage fluctuations. The devices include fixed output versions at both ends and three-terminal adjustable output versions such as NSI50010YT1G, NSI45015WT1G, NSI45020T1G, NSI45020AT1G and NSI45020JZT1G. Bus transceiver The LIN/CAN bus is used to implement distributed electronic system control in automobiles. For this type of application, ON Semiconductor offers LIN/CAN transceivers such as NCV7321 and NCV7342, all of which comply with the IEC61000-4-2 standard. The system's ESD protection capability of the NCV7342 is higher than 15kV and the short-circuit current does not exceed 100mA. Electromagnetic compatibility (EMC) performance, even without the need for common mode chokes. System base chip System Basis Chip (SBC) refers to integrated in-vehicle networks (such as LIN, CAN, FLEXRAY), power supplies (such as linear regulators, DC-DC regulators), monitoring (such as watchdog, SPI, status, interrupts). And systemized chip solutions for I/O (such as high-side, low-side, LED, etc.). ON Semiconductor's SBC for automotive air conditioning, such as the NCV7420/5/8, is an integrated LDO LIN transceiver with output currents of 50mA, 150mA, and 70mA. Conclusion The comfort and energy saving brought by automotive automatic air conditioning is of concern to consumers and automotive design engineers. The extensive product line of ON Semiconductor for automotive air conditioning includes power supply, motor drive, SmartFET, discrete components, etc., after strict automotive grade products. Certification, high performance and high reliability help to achieve high efficiency and energy saving in automotive air conditioning systems, providing consumers with a comfortable driving experience. Pay attention to ON Semiconductor's official WeChat to learn more innovative and energy-efficient solutions usb cable, usb-c types, usb c charging cable, best charging cable for iphone, usb c cable TOPNOTCH INTERNATIONAL GROUP LIMITED , https://www.micbluetooth.com
