Highly Integrated DC motor controller with Bridge predriver for Smart Actuators

Melexis introduces the MLX81100 DC motor controller with embedded Flash memory and CPU for automotive high current applications. DC motor control, diagnostics and protection is greatly simplified with the highly integrated MLX81100 and a few simple power NMOSFETs. The MLX81100 is the first member of the new ‘MelexCM’ family of automotive actuator ASSPs with embedded Flash memory.

Safety critical high current DC motor actuator applications, like wipers, seatbelt retractor, steering column lock, electric brakes as well as pumps, heaters and blowers can benefit most from Melexis new line of embedded Flash memory microcontrollers. The high temperature capability of the MLX81100 makes it particularly suited for engine flaps like throttle, manifold, turbo and EGR. The MLX81100 like all ‘MelexCM’ products consists of a 5MIPS dual task Flash CPU die with a dedicated high voltage die, which integrates voltage regulator, RC oscillator, high voltage IO’s, LIN transceiver and ADC. Additionally the MLX81100 has an integrated programmable H-bridge predriver with low side shunt measurement to enhance DC motor control applications.

The MLX81100 controls, diagnoses and protects a reversible DC motor application using only simple power NMOSFETs. It integrates all standard automotive protections to plug it directly on to the 12V board net, including over-voltage, short circuit and load dump (40V) protection. The integrated MOSFET gate-driver and FET monitoring circuits on one chip make additional FET predriving circuits superfluous and reduces significantly the systems BOM.

The MLX81100 is based on the ‘MelexCM’ platform, a new low cost integration concept, which was developed especially for automotive actuator applications. This MelexCM Multi-Chip concept combines two dies in one 6 x 6 mm QFN package. The digital die leverages the high gate density of a 0.18µ flash technology and contains functions like a dual task CPU, timer, PWM and embedded Flash memories. The second die is designed in a mixed signal 0.8µ or 0.35µ technology and contains all analog and high voltage blocks like regulator, LIN bus transceivers and output drivers. A dedicated communication interface between both dies assures that from the software perspective the peripherals on the analog IC can be accessed in a single instruction, just like in a monolithic single chip solution.

Via SPI or UART interface it is possible to connect external position sensors like the MLX90316 360° Absolute position sensor. Eight high-voltage capable I/Os offer a connection to the external world. The 30µA sleep current makes the MLX81100 also well suited for applications with stringent standby demands.

For software development a complete support environment is available including an in-circuit-emulator, GNU C-compiler and high level debugger, evaluation PCB and software library routines. Furthermore 30kByte Flash memory, 2Kbyte RAM and 128Byte EEPROM are available for the customer’s software. Other application peripherals include three dual 16-bit capture and compare timer and a wide range of communication interfaces like an integrated LIN interface including physical and protocol layer, PWM or SPI interface.

Availability: Engineering samples are available today.