onsemi System Solution Guide - Preview

Overview

Small Electric Vehicles (SEVs)

Small Electric Vehicles (SEVs) encompass a broad spectrum of vehicle types, each with distinct construction and power ratings. The selection of components for the main inverter stage, DC/DC power management, and sensory equipment is largely dictated by the vehicle's intended application, size, and cost considerations. onsemi's extensive product portfolio provides scalable solutions designed to enhance motor efficiency, optimize power delivery, and integrate advanced sensing capabilities. While each SEV presents unique power and control requirements, common Bill of Materials (BOM) elements often include control circuits, protection components, and communication interfaces.

The integration of advanced features such as image and ultrasonic sensing in industrial SEVs, like forklifts or tow tractors, can significantly enhance driver convenience and operational safety within industrial settings such as factories and warehouses.

System Description

Types of SEVs – Transportation and Recreation

This section likely details the various types of SEVs used for transportation and recreational purposes, such as personal mobility scooters, golf carts, and electric bicycles.

Types of SEVs – Industrial

This section likely covers industrial SEVs, including forklifts, tow tractors, and pallet jacks, highlighting their specific requirements and applications.

Small Electric Vehicles - Block Diagram

The interactive block diagram illustrates the key components of an SEV system. It shows the flow of power from the battery (24V-80V) through power management (Power/Load Protection, DC-DC Conversion) to the motor drivers and main motor inverter, which powers the vehicle engine. Other critical components include the Battery Management System (BMS), Vehicle Networking, Signal Processing, LED Drivers, Interface Components (MCU Interface), Image Sensor, and Ultrasonic Sensor. An external charger is also depicted for AC input.

The diagram allows users to explore components in context and access more detailed information on sub-blocks like the Main Motor Inverter and External Charger. It also highlights auxiliary power supplies, LDOs, SmartFETs for power switching and protection, and CAN transceivers for communication. The tool is designed to help identify suitable components for various SEV designs, from lightweight mobility scooters to heavy-duty airport tow tractors.

Solution Overview

Discrete Si MOSFETs for SEV Applications

Discrete Silicon (Si) MOSFETs are fundamental electronic components in SEVs, fulfilling crucial roles in motor inverters, battery management systems, protection circuits, and LED lighting drivers. onsemi offers a wide selection of Low Voltage (LV) and Medium Voltage (MV) MOSFETs tailored to meet the diverse power requirements and battery voltages of different vehicles. Designers can choose from various component technologies and packages. It is crucial to maintain adequate VDS (Drain-Source Voltage) headroom to prevent damage from voltage spikes caused by inductive kickback. Motor inverters are particularly sensitive to these spikes compared to protection applications.

Alternative design options include compact TCPAK57 and TCPAK10 packages featuring top-side cooling, which facilitates heat dissipation through the exposed drain on the package's top. Additionally, Dual Cool packages offer cooling pads on both the top and bottom of the package, designated for source and drain pins, respectively.

Table 3: Recommended onsemi MOSFETs for 12V, 48V and 80V systems.

• 40V MOSFET
• 60V MOSFET
• 80V MOSFET
• 100V MOSFET
• 120V-150V MOSFET

PowerTrench® T10 Shielded Gate Trench Technology

onsemi's PowerTrench® T10 technology is engineered for DC-DC conversion (T10S variant) and motor control/load switch (T10M variant) applications. This technology optimizes efficiency, offers low output capacitance, and provides superior figures of merit (FOM) characterized by lower RDS(ON) and gate charge (Qg). The vertical channel and shield electrode design enable higher epi doping and increased channel density, resulting in lower RDS(ON). Compared to traditional trench MOSFETs, T10 technology achieves lower specific resistance (RDS(ON) per unit area) and improved FOM. Furthermore, enhancements in the soft-recovery body diode (Qrr, Trr) due to silicon layout improvements lead to reduced ringing, overshoot, and noise, surpassing the performance of legacy T8 and T6 technologies.

The document includes graphs comparing the performance of 40V and 80V Power MOSFETs across different technologies (PowerTrench® T10, T6, T8) and packages (u8FL, SO-8FL, LFPAK56, Dual-Cool, PWR88, TOLL, Other), illustrating the relationship between Qg and RDS(ON).

LED Drivers for Small Electric Vehicles

LED Lighting and Linear Drivers for Vehicle Lights

Effective lighting is crucial for all vehicles, ensuring road illumination and safety functions. In transportation, lighting enhances visibility across various weather and lighting conditions for both drivers and other road users. Within industrial environments like manufacturing plants, warehouses, and airports, vehicle lighting plays a vital role in signaling presence, movement, and operational intent. Industrial vehicles often feature specialized lighting tailored to specific tasks. For instance, colored warning and strobe lights on forklifts improve visibility and help prevent accidents by alerting nearby personnel. In outdoor industrial or airport settings, LED beacon lights are commonly used to enhance operational safety. Across all applications, lighting systems must be highly reliable and durable, particularly in low-visibility conditions.

LEDs offer significant advantages over traditional lighting technologies, including superior energy efficiency, reduced weight, and extended lifespan. onsemi provides a comprehensive range of LED drivers and controllers to address diverse power and application needs. For signaling applications using RGB LEDs, multi-output linear LED drivers provide precise control. Linear LED drivers serve as an alternative to Switched-Mode Power Supply (SMPS) LED drivers. onsemi's versatile LED driver solutions are suitable for various applications, including front lights, fog lamps, rear lights, signal and warning indicators, externally modulated applications, and dashboard lighting.

12 Channel - Linear LED Driver NCV7685

• Features 12 linear programmable constant current sources.
• Duty cycle is adjustable via PWM using an I2C interface.
• Advanced signal control is achievable through individual PWM channels.
• Supports independent PWM duty cycle control with up to 60mA per channel.
• Includes open LED string and undervoltage diagnostics.
• Provides independent diagnostic feedback for each function.
• Supports on-chip 150, 300, 600, or 1200Hz PWM.
• Requires a single resistor for current setting.
• Available in an SSOP-24 package.

8 Channel - Linear LED Driver NCV7683

• Features 8 programmable constant current sources for LED rear combination lamps.
• Supports two programmed duty cycle levels for stop and taillight functions, or PWM dimming.
• Can be utilized in applications without MCU communication, reducing system costs.
• Supports 8 channels, with up to 100mA per channel.
• Includes open LED string diagnostics.
• Features on-chip 800Hz Tail PWM dimming.
• Requires a single resistor for current setting.
• Requires a single resistor for tail dimming setting.
• Available in an SSOP-24 package.

NCV7685 Evaluation Kit

This evaluation kit utilizes multiple NCV7685 drivers to demonstrate a vehicle rear-combination lamp application. The board is controlled by a Body Control Module (BCM), which can activate the board's functions and provide diagnostic information. The evaluation kit also includes full animation control, individual LED control, and an RSL10 for control via Bluetooth interface.

Complementary Products

This section likely lists other onsemi products that complement the solutions for SEVs, such as power modules, gate drivers, and sensors.

Development Tools and Resources

This section provides information on development tools and resources available from onsemi to aid in the design and implementation of SEV systems. This may include simulation tools, reference designs, and technical documentation.

Technical Documents

This section likely directs users to relevant technical documentation, such as datasheets, application notes, and user manuals for the products discussed in the guide.