Introduction Electric vehicles (EVs) typically feature a large DC link capacitor (CDC LINK) to minimize voltage ripple at the input of the traction inverter. When powering up an EV, the purpose of precharging is to safely charge up CDC LINK before operating the vehicle. Charging CDC LINK up to the battery stack voltage (VBATT) prevents arcing on the contactor terminals, which can lead to catastrophic failures over time. The conventional precharge method involves implementing a power resistor in series with the CDC LINK to create a resistor-capacitor (RC) network. However, as the total CDC LIN ..read more

Automotive ethernet is increasingly utilized for in-vehicle electronics to transmit high speed serial data between interconnected devices and components. Due to the relatively fast data rates, and the complexity and variation of the networked devices, signal integrity issues can often arise. This article outlines several real-world challenges and provides insight into how to identify and debug automotive ethernet physical layer signal integrity problems using an oscilloscope. The following is a case study of automotive ethernet debugging performed at Inspectron, a company that designs and man ..read more

Toshiba’s SmartMCD series of gate drivers with embedded MCUs offers sensorless control of three-phase BLDC motors in automotive applications. The first entry in the series, the TB9M003FG combines a 32-bit Arm Cortex-M0 core, 64 kbytes of flash memory, and power control functions for driving N-channel power MOSFETs in drive systems for water pumps, oil pumps, fans, and blowers. The integration of a microcontroller helps reduce design size and component count, while enabling complex motor control. To minimize the load on the MCU, the gate driver employs a vector engine and hardware for sensorl ..read more

Aspinity has launched a dashcam evaluation kit and a suite of smart analogML algorithms for parked vehicle monitoring. The hardware/software offerings leverage the company’s always-on AML100 analog machine learning processor. The near-zero power AML100 enables continuous monitoring for extended periods without impacting the vehicle’s battery or requiring an external power source. The company recently demonstrated a dashcam with a single microphone and an AML100 processor. The setup uses an acoustic-only trigger and analogML algorithms trained to identify automotive security events. According ..read more

At this year’s APEC in Long Beach, California, Wolfspeed CEO Gregg Lowe’s speech was a major highlight of the conference program. Lowe, the chief of the only vertically integrated silicon carbide (SiC) company and cheerleader of this power electronics technology, didn’t disappoint. In his plenary presentation, “The Drive for Silicon Carbide – A Look Back and the Road Ahead – APEC 2024,” he called SiC a market hitting the major inflection point. “It’s a story of four decades of American ingenuity at work, and it’s safe to say that the transition from silicon to SiC is unstoppable.” Figure 1 L ..read more

Electronics design engineers bear the responsibility of overcoming the world’s concerns with electric vehicle (EV) power sources. Lithium-ion batteries are heavy, put pressure on natural resources, and sometimes are slow to charge. The logical next step in EV development is using ultracapacitors as a complementary power source for when there are not enough batteries to go around, allowing electrification to scale and tone down the detractors of modern charging electronics. Looking to ultracapacitors may remove some of the market uncertainties surrounding other EV power generators. The electro ..read more

Step-down converters’ switch-node voltage waveform defines the electromagnetic compatibility (EMC) behavior for automotive CISPR 25 Class 5 measurements. The ringing frequency in the switch-node waveform is an important signal on the EMC receiver, where a higher ringing amplitude on the switch node often causes EMC issues. Understanding the switch-node waveform enables predicting the converter’s EMC characteristics as well as optimizing EMC filter design at an early design stage. This article compares three automotive step-down converters to provide practical advice on using switch-node wavef ..read more

A PWM linear LED driver, the AL1783Q from Diodes, provides independent control of brightness and color on all three of its channels. Used for automotive interior and exterior lighting, the AL1783Q delivers 250 mA per channel to support higher LED current ranges in a wider range of lighting applications. The device allows vehicle occupants to change interior lighting colors to suit their mood. It simultaneously enables animated turn-indicator signals and exterior grill lighting for different road conditions. Three external REF pins are used to set LED current for each channel, while 40-kHz PW ..read more

Two linear power amplifiers (PAs) and two low-noise amplifiers (LNAs) from Guerrilla RF serve as signal boosters to enhance in-cabin cellular signals. Qualified to AEC-Q100 Grade 2 standards, the GRF5507W and GRF5517 PAs and the GRF2106W and GRF2133W LNAs operate over a temperature range of -40°C to +105°C. The GRF5507W power amp has a tuning range of 0.7 GHz to 0.8 GHz, while the GRF5517W spans 1.7 GHz to 1.8 GHz. Each device delivers up to 23 dBm of output power with adjacent channel leakage ratio (ACLR) performance of better than -45 dBc. Further, this ACLR figure is achieved without the ..read more

Less than a year after Infineon snapped GAN Systems to bolster its gallium nitride (GaN) technology roadmap, another GaN semiconductor specialist is becoming part of a bigger semiconductor company’s product portfolio. Renesas is acquiring Transphorm to leverage its GaN expertise in power electronics, serving a wide range of segments like automotive, consumer, and industrial. The acquisition deal, amounting to approximately $339 million, is expected to be complete by the second half of 2024. Subsequently, Renesas aims to incorporate Transphorm’s automotive-qualified GaN technology in its X-in ..read more