Differentiation is the name of the game in today’s automobile business, and electronics continues to be a major part of differentiation. For the motors, solenoids, displays and lighting, semiconductor suppliers have rolled out several integrated circuits and discrete components to power each load as well as the circuitry that controls it. These products control vehicle loads in an increasingly efficient and highly reliable manner. Some of the simplest discrete devices, such as MOSFETs, IGBTs and LEDs provide the greatest potential to reduce fuel consumption and increase vehicle range.

The newest cars demonstrate why new semiconductor products are required. For example, the 2010 Lexus IS 250C has numerous examples of electrical and electronic technology. In the convertible, 15 electric motors raise and lower the three-piece hard top (Fig. 1). For quiet operation, a roof-speed brake-control system decreases the roof speed as the roof approaches the end of the closing operation in either direction.

In addition to the increase in motor controls, the 250 IS uses LED technology in the tail lamp cluster and brake lights. The car also has electric power steering, direct fuel injection, a hard-disk drive (HDD) navigation system, a premium 270-W surround sound audio system, and much more electronics. However, the 250 IS is just one example of electronics technology in vehicles.

Figure 1. With all of the hinges in the 3-piece hardtop and the trunk, it takes 15 electric motors less than 21 seconds to raise and lower the roof automatically in the Lexus HIS 250 convertible Source: Toyota

The 2011 Audi A8 demonstrates LED technology applied to headlights where the technology can provide significant power reduction. Instead of consuming as much as 65 W for an incandescent high beam or 55 W for a low beam, an LED headlamp could be in the 5 W to 7 W range. In addition to full LED lighting, the A8 boasts 13% to 22% reduced fuel consumption compared to the previous model through brake energy recuperation and thermal management systems. The 3.0 TDI (turbocharged direct injection) also has a start-stop system.

Due to the growth of electronic systems, sales of power semiconductors are increasing at a compounded average annual growth rate (CAAGR) rate of 9.4% according to market research firm Strategy Analytics. "The two fastest-growing areas are HEV (hybrid electric vehicle) and alternator -- the alternator growth being driven by micro hybrid start-stop designs," says Ian Riches, director, Global Automotive Practice at Strategy Analytics. Today’s largest power semiconductor consuming systems include body and internal combustion (IC) engine control (Fig. 2).

The addition of greater electronic control has placed constraints on power consumption. ”We have seen increased interest in saving watts-per-module over recent years and months. However, the ever-increasing amount of electronic features fitted to cars means that the demands on the vehicle EE network are arguably greater than ever,” says Riches.

Changes for the Micro Hybrid

Figure 2. The total power semiconductor demand is increasing in every automotive system. Select figure to enlarge. Source: Strategy Analytics

A closer examination of micro hybrids and alternators reveals the requirements and the driving forces behind industry developments to address increased efficiency for these and other systems. Automotive OEMs and their tier one suppliers continuously provide new requirements to semiconductor suppliers. This input can incrementally improve existing systems or enable new systems. Micro hybrid technology represents a fundamental change in the powertrain system providing stop-start (stop-go) and/or regenerative braking.