ON Semiconductor's functional electronic solution for hybrid electric vehicles/electric vehicles

Increasingly stringent energy efficiency and environmental regulations drive the growing trend of automotive electronic functions and the increasing popularity of hybrid electric vehicles/electric vehicles (HEV/EV), which increases demand for energy-efficient and high-performance power and power semiconductor devices . As one of the leaders in automotive electronics and one of the world's second largest power discrete device and module semiconductor suppliers, ON Semiconductor offers a wide range of energy efficient and highly reliable system solutions with new wide bandgap materials such as silicon carbide. New product developments such as (SiC) and gallium nitride (GaN) are used for automotive electronic functions and HEV/EV applications.

Key applications for HEV/EV include: car charger, battery management, traction inverter, auxiliary inverter, 48 V belt starter generator (BSG) and DC-DC converter.

A typical HEV/EV high voltage application block diagram is shown in Figure 1. The AC power source outputs DC power through the car charger, and the battery management system charges the high voltage battery. At the same time, the high voltage battery supplies power to the main inverter, the auxiliary high voltage inverter and the high voltage PTC heater. In addition to the above high voltage load, the HEV/ EV cars also have a lot of low-voltage loads that require high-voltage to low-voltage (HV-LV) DC-DC to provide power.

Figure 1: Block diagram of a typical HEV/EV high voltage application

For vehicle chargers, trench IGBT discrete devices and modules, super-junction MOSFETs, SiC MOSFET discrete devices and modules can be used as PFC boost switches and DC-DC full bridges, while rectifiers are used as input and output rectifier bridges and PFC boost applications. . For the main inverter, IGBT die, SiC MOSFET die, discrete devices and modules can be used. For HV-LV DC-DC, trench IGBT discrete devices and modules, super-junction MOSFETs, SiC MOSFET discrete devices and modules can be used as full bridges, and rectifiers are used as output rectifier bridges. For auxiliary inverters, trench IGBT discrete devices and modules can be used. For high voltage PTC heaters, trench and planar IGBT discrete devices are available. For 48 V BSG, a medium voltage MOSFET module can be used.

ON Semiconductor's IGBT technology is the industry leader, moving from the earliest through-type (PT), non-punch-through (NPT) to the current field-cutting (FS) plane and trench process. The characteristics and performance of FS IGBT are: low conduction and switching loss; positive temperature coefficient for parallel operation; maximum junction temperature: Tj = 175degC; tight parameter distribution; large safe working area (SOA). At present, the performance of ON Semiconductor's third-generation field cutoff (FSIII) process is close to the industry's top level, and the FSIV process will begin to be developed in 2018.

ON Semiconductor currently offers automotive-grade discrete IGBTs with voltages ranging from 600 V to 650 V and currents ranging from 20 A to 160 A, as well as D2PAK and TO247 options.

Table 1: ON Semiconductor's discrete IGBT lineup for HEV

In addition to traditional discrete devices and modules, ON Semiconductor also offers automotive grade die. The company's mass-produced IGBT and fast recovery diode (FRD) die are primarily 650 V products with currents of 160 A, 200 A and 300 A. At the same time, we are actively developing 750 V and 1200 V IGBT and FRD dies.

ON Semiconductor offers IGBT dies with integrated current sensing and temperature sensing. The current sense function is implemented by measuring the current of a small parallel IGBT and multiplying it by a known scaling factor. It is suitable for overcurrent, chipset algorithms to improve current detection accuracy over temperature. The temperature sensing function is implemented by measuring the forward voltage VF of a string of polysilicon diodes. The VF is linearly related to temperature and serves as an accurate temperature sensor for the silicon junction.

According to different applications, the rectifier can choose products with lower conduction loss or lower switching loss. The main features and applications of various products are shown in Figure 2.

Figure 2: Technical positioning of the rectifier

ON Semiconductor's mass-produced automotive-grade high-voltage rectifiers include 600 V, 1000 V, and 1200 V, with currents from 4 A to 80 A, and are available in a variety of package options including DPAK, TO220, and TO247.

Table 2: ON Semiconductor's Automotive Grade High Voltage Rectifier Lineup

ON Semiconductor has innovated a two-sided heat-dissipating automotive high-voltage power module for traction inverters, using dual-sided solderable process wafers for integrated current and temperature sensing, combined with a compact layout to achieve the best thermal performance of its class and Electrical performance: Reduced thermal resistance by approximately 40% with stray inductance as low as 7 nH. Its modular construction increases power density, reduces size, weight and cost for a compact system design. The optimum trench performance is achieved by the best trench field stop IGBT with soft recovery diode. A single die with ultra-low parasitics enables a simplified gate driver with additional surface for passive cooling of other electronics such as bus capacitors, and precision sensors for high speed and accurate system diagnostics.

Available in 650 V and 1200 V voltage ratings and rated currents from 400 A to 1000 A, the modules are available in a wide range of power ratings up to 6 for complete hybrid inverter power transmission systems including boost converters. Achieve the lowest system cost.

Its modular and versatile design enables horizontal and vertical assembly. For horizontal mounting, the power supply pins support screws, solder or solder connections, and offer a variety of pin bend options. The signal pins support the press fit option. For vertical installations, the ultra-compact 3D concept is ideal for hybrid electric vehicles and plug-in hybrid electric vehicles (HEV & PHEV), with integrated inverters, generators and DC-DC boosters to a single liquid cooling system.

SJ MOSFETs are new MOSFETs that utilize charge balancing techniques to achieve excellent low on-resistance and low gate charge performance to minimize conduction losses and provide excellent switching performance. Figure 3 shows the evolution of the 650 V SJ MOSFET technology.

Figure 3: 650 V SJ MOSFET Technology Evolution

The SJ MOSFET versions are compared as follows:

The fast version is implemented by minimizing Crss. Key features include: Energy efficient, hard switching topology, reduced Qg and Eoss, mainly for boost PFC, full bridge, bidirectional Buck-Boost, semi-bridgeless PFC.

Easy-to-drive version with built-in Rg, low gate oscillating, low EMI and voltage spikes, easy drive, lower control Coss, hard/soft switching topology, etc. Mainly used for boost PFC, semi-bridgeless PFC, phase Move DC-DC.

The fast recovery version is mainly realized by carrier lifetime control. The main features are: fast body diode, small Qrr and Trr, strong diode, better reliability, soft resonant switch, mainly used in LLC, LCC, dual Topology such as source bridge type DC-DC.

In the same package, SuperFET® III is nearly 50% smaller than the SuperFET® II's Rds (on), providing higher power density for high-power on-board charging systems, and fewer parallel MOSFETs require less space. Thus, the layout crosstalk of the parallel devices is made smaller.

The lineup of automotive SJ MOSFETs and die that Masson has produced in mass production is shown in Table 3.

Table 3: ON Semiconductor's SJ MOSFET and die lineup

The wide bandgap semiconductor material is called the third generation semiconductor material, represented by SiC and GaN, and has the characteristics of large band gap, high breakdown electric field, and high thermal conductivity, providing excellent switching performance, temperature stability and low performance. Electromagnetic interference (EMI). Taking SiC as an example, it has 10 times higher dielectric breakdown strength than silicon (Si), 2 times higher electron saturation speed, 3 times higher energy band gap, 3 times higher thermal conductivity, and higher switching. The frequency supports smaller magnetic and passive components, reducing the size and cost of the overall system. The use of SiC reduces the weight of the system compared to the traction inverter or car charger with Si, requires less cooling and provides higher energy efficiency. This increases the cruising range of each charge. GaN has excellent breakdown capability, higher electron density and speed, and higher operating temperature. Its high electron mobility means better switching performance, while low loss and high junction temperature reduce heat dissipation. The high switching frequency reduces the use of filters and passive components, ultimately reducing system size and weight and increasing power density.

ON Semiconductor is the only supplier to offer both GaN and SiC devices, and is actively developing more different devices to meet the needs of HEV/EV automotive applications.

The target applications for automotive high-voltage auxiliary IPM are all auxiliary IPMs in pure electric vehicles, plug-in hybrid vehicles, heavy hybrid vehicles, medium-duty hybrid vehicles, and fuel cell vehicles, including high-pressure cooling fans, turbochargers, and air-conditioning compression. Machine, high-pressure electric water pump / oil pump / fuel pump, etc.

The automotive high-voltage IPM module is based on an excellent DBC substrate with ultra-low thermal resistance, ensuring Tj=175°C, providing best-in-class temperature cycling test and power supply reliability for long life and excellent ruggedness, even at worst In case of short circuit time of more than 5 us, it is integrated in a highly integrated and compact package, integrated with 6 power devices / HVIC / DBC / comprehensive protection, etc., short design cycle and assembly process to achieve IPM fully optimized to provide stable EMI and heat performance.

ON Semiconductor is currently developing the ASPM® 27 Series V2 and ASPM® 34 series for automotive electric air conditioning compressors, automotive fans, super chargers, and oil pumps/water pumps.

With leading packaging technology, semiconductor design, manufacturing capabilities and fast response capabilities, ON Semiconductor offers automotive power modules from 0.8 kW to 20 kW and voltages from 12 V to 470 V for electric power steering, braking and acceleration skid protection System (ARS), air conditioning compressor, super charger, belt / integrated starter generator, DC-DC converter, battery switch, car charger and other applications, and customize different package designs and solutions according to customer needs and provide fast response.

The lineup of ON Semiconductor's standard APM19 and APM17 automotive modules is shown in Table 4.

Table 4: ON Semiconductor's APM19 and APM17 Automotive Module Lineups

As one of the leaders in automotive electronics and the world's second-largest supplier of power discrete devices and module semiconductors, ON Semiconductor has best-in-class IGBTs, MOSFETs, WBG technology, and innovative and efficient power module packages for Automotive features a wide range of energy-efficient, high-reliability automotive power semiconductors, and can be customized according to customer needs, through the world-class supply chain, with the electronic trend of automotive functions and to meet the needs of different applications.