Traditional automotive industry has gradually developed towards electronization and electrification. In addition to a variety of electric vehicles (hybrid and pure electric vehicles), there are more and more electronic components in fuel vehicles both internally and externally. This article will show you the development direction of automotive electronization and electrification, as well as functional characteristics of related products launched by ST.
Electronically turning the automotive industry from the inside out
Automotive electronization and electrification do not only refer to the development of fuel vehicles towards electric vehicles. In fact, even traditional fuel vehicles continue to develop towards electronization. For example, more and more electronic components have also been used in the infotainment system, vehicle control system, auxiliary driving system, dashboard, internal lighting and decoration, and external lighting system, which has changed the design thinking of traditional vehicles significantly. Automobiles take different forms and have different looks from the inside out.
In addition to pure electric vehicles, some hybrid vehicles have been introduced, combining the advantages of fuel vehicles and electric vehicles. When driving at high speeds, internal combustion engine power is used, and battery charging is recovered. When driving at slow and idle speeds, it is battery driven to reduce fuel consumption. In general, hybrid vehicles have better fuel efficiency and acceleration performance than pure internal combustion vehicles of the same type, while disadvantages include high selling price, large space occupied by power system, and limited battery life.
On the other hand, the intelligent development of automobiles is not the exclusive function of electric vehicles. Traditional fuel vehicles or hybrid vehicles also evolve towards networking and automatic driving. Automobiles are increasingly intelligent, reducing the driving burden and providing better safety. This also makes it necessary for automobiles to adopt more and more electronic components. It is a huge market opportunity for the electronics industry.
32-channel O/LED driver with automotive CAN FD Light interface
Currently, exterior lighting in automobiles has adopted an increasing number of O/LEDs to design rear lighting, presenting a more future-sensitive shape for automobiles. The L99LDLH32, introduced by ST, is a 32-channel adjustable constant current regulator specifically for automotive exterior small current O/LED light applications. Thanks to the high side configuration of the output channels, it is suitable to drive O/LED panel with common cathode. It provides up to 35 V output to cover the O/LED wide spread - and features 32 channels of independent 1 mA - 15 mA programmable current and PWM adjustment to adjust each pixel of the O/LED panel independently.
As the other device in the L99LDLL16 family, L99LDLH32 adopts CAN FD Light communication network compatible with CAN FD Light. Applicable to today's automotive lighting systems, this CAN-based lightweight network has been proved to meet system needs and advantages which allows a high-rate data transmission (up to 1 Mbit/s) and uses CAN FD for long frames structure. It supports up to 128PCS cascade, compatible with the use of large data pixels.
The CAN FD Light not only has a compatible physical layer, the device also integrates CAN transceivers, LDOs, oscillators, etc., so its peripherals are very streamlined. In addition to the CAN FD Light compatible interface, the L99LDLH32 can operate in bus mode, using programmable EEPROM (FTP) memory to set 2 independent modes (Limp Home) and compatible with external ports Din/CAN BUS/power line 3 PWM dimming modes.
L99LDLH32 is AEC-Q100 qualified, ASIL B safety level with CAN FD Light compatible serial interface, Protocol Handler, Draft Specification Proposal (DSP) available from CAN in Automation (CiA). It has QFN48L 7x7 with exposed pad and timeout watchdog with Limp Home. It features low standby current and standalone/fail safe and bus mode operation. It has a direct drive (1 direct Input), for 1 function group supporting ASIL requirements, realizing widest configurability by embedded non-volatile and volatile memories. The operating supply voltage range is from 5.5 V to 40 V.
The L99LDLH32 linear regulators section can operate within the operating temperature range of -40℃ – 150℃. It can feed back voltage to external pre-regulator, to optimize the regulation voltage minimizing overall power dissipation. It implements current setting per channel by 8-bit DAC. It supports analogue dimming, 8-bit PWM channel individual exponential brightness control and 8-bit global PWM dimming, and programmable PWM frequency. It has slow turn on/off time, gradual outputs delay and dithered clock, for better EMC performances.
L99LDLH32 is integrated with 8-bit ADC, for full and flexible diagnostic. It has 1 dedicated line for fault bus and provides temperature warning, over-temperature shutdown (2 temperature thresholds), short circuit and open load detection and protection. It can implement automatic LED current derating, through external NTC measurement and device junction temperature (TJ). A temperature sensor is integrated inside the chip, and an external thermistor is supported to measure the external ambient temperature. The dual-temperature multiple protection and diagnostic functions ensure the safe and stable use of the lights.
L99LDLH32 supports the control of up to 2 individual lighting functions and each channel can be mapped or not mapped to a direct input, as well as pre-regulated external power supply voltage, which ensures maximum flexibility in controlling different lighting functions consisting of different O/LED types, currents and lamp string lengths for applications such as automotive O/LED rear lighting and automotive ambient lighting.
BMS provides complete battery monitoring and protection
The BMS must meet a variety of critical functions, such as voltage, temperature, and current monitoring, battery state of charging (SoC), and cell balancing for lithium-ion (Li-ion) batteries. A BMS requires battery protection to prevent the operational safety from going outside its safe operating area and to monitor batteries by estimating the state of charging (SoC) and state of health (SoH) of the battery pack during charging and discharging. Battery optimization also benefits from battery balancing. It improves battery life and capacity, and thus optimizes the driving range of hybrid electric vehicles (HEV), plug-in hybrid vehicles (PHEV), and battery electric vehicles (BEV).
ST's BMS solution for automotive applications is specifically conceived to meet demanding design requirements. Based on the new highly-integrated Battery Management IC L9963E and its companion isolated transceiver L9963T, this solution is able to provide the highest accuracy measurements of up to 14 cells in series, on mono or bi-directional daisy-chain configuration, embedding sophisticated cell monitoring & diagnostic features. It also meets the stringent ISO26262 standards and Automotive Safety Integrity Level (ASIL) D compliance.
The L9963E is a Li-ion battery monitoring and protecting chip for high-reliability automotive applications and energy storage systems. 4 to 14 stacked battery cells can be monitored to meet the requirements of 48 V and higher voltage systems. Each cell voltage is measured with high accuracy, as well as the current for the on-chip coulomb counting. The device can monitor up to 7 NTCs. The information is transmitted through SPI communication or an isolated interface.
Multiple L9963Es can be connected in a daisy chain and communicate with one host processor via the transformer isolated interfaces, featuring high-speed, low EMI, long distance, and reliable data transmission. Passive balancing with programmable channel selection is offered in both normal and low power mode (silent balance). The balancing can be terminated automatically based on an internal timer interrupt. Nine GPIOs are integrated for external monitoring and control. The L9963E features a comprehensive set of fault detection and notification functions to meet AEC-Q100 safety standard requirements.
Offering full protection of battery modules with a microcontroller
In addition, together with ST’s 32-bit Automotive MCU family, Power Management & System Basis ICs, VIPower Smart Switches, a wide offering of Protection Devices and automotive EEPROMs for datalogs, ST comes with a comprehensive and flexible solution to support your automotive-grade BMS design.
ST's L9963 Battery Monitoring and Protection IC handles up to 14 Li-ion battery cells, and can be stacked vertically to monitor up to 15 battery packs, corresponding to a nominal battery voltage of several hundred volts, and monitor the voltage, current, and temperature of a single battery or battery pack with 16-bit resolution.
L9963 is suitable for performing battery balancing and SOH and SOC calculations based on data collected through one or more L9963 assisted by the SPC5 family of automotive MCUs. This BMS solution is built using SPC57 4S series high-performance MCUs with up to 1.5 MB of flash memory and 128 KB of RAM. This MCU has two CAN-FD interfaces, eight extensively triggered enhanced 12-bit ADCs, supports ASIL-D functional safety standards, and is packaged with QFP100 and operates at temperatures up to 150°C.
Depending on end-use performance and safety level requirements, the proposed implementation scheme can be adapted to various ST’s automotive MCUs. The SPC58 G family provides the highest overall performance, supports up to three cores and up to 6 Mbytes of memory, and increases hardware security compliance with EVITA and SHE standards. Another advantage of the L9963 is that it is compatible with isolation technology using transformer-based or capacitor-based in universal communication interfaces and BMS applications, and devices can operate in different voltage domains.
Conclusion
Driven by the development of automotive electronization and electrification, automobiles, whether traditional fuel vehicles, hybrid vehicles or pure electric vehicles, will become safer and smarter. These changes have brought a new look to automobile design and huge business opportunities to the electronics industry. Several ST products introduced herein are only a microcosm of automotive electronization. There is still much room in the market. They are worthy of creativity to seize new blue sea business opportunities in the automotive industry.