New Industry Products

STMicro Introduces Integrated Automotive IC To Consolidate Door-Mounted Drivers

October 21, 2008 by Jeff Shepard

STMicroelectronics (ST) is claiming that it is the first company to introduce a single chip that produces the major signals required to drive vehicle door-mounted systems as well as an improved method for controlling electrochrome (EC) rear-view mirrors. The L99DZ70XP combined driver IC eliminates discrete drivers normally mounted in multiple locations inside the door, allowing compact, integrated door-zone controllers which the company states are easier to fit and deliver greater long-term reliability.

The L99DZ70XP’s integrated EC-mirror controller is described as a first for automotive driver ICs. According to the company, conventional EC controllers typically use a regulator that requires a high-power external resistor, but the L99DZ70XP generates control signals for a small external MOSFET driving the EC element. This is said to save space and cost, and also allows closed-loop current control for enhanced reliability.

Six of the L99DZ70XP outputs are optimized for motor-drive applications such as mirror positioning and folding, and door-lock actuation. Up to four drivers are available for lighting applications, and two of these can be programmed to drive either LEDs or conventional bulbs. Another output is optimized to drive the mirror defroster. Each of the drivers uses pulse-width modulation for accurate current control. Other capabilities include soft starting for loads such as motors or bulbs, to prevent high initial currents causing potentially damaging surges within the vehicle wiring. The L99DZ70XP uses serial communications over an industry-standard SPI link to exchange information with the host controller, including diagnostic information for each output to aid fault-finding and repair.

The L99DZ70XP adds to ST’s Door Zone family of integrated drivers, which already features seven devices offering a range of functions for driver-side, front-passenger and rear-passenger doors in vehicles targeting a variety of markets. The L99DZ70 is qualified to automotive standards and delivered in a 36-pin PowerSSO-36 package with enhanced thermal properties for high reliability in all automotive operating environments.

Samples are available immediately, with volume production scheduled for Q1 2009 at $3 for 100,000 pieces.