Melexis MLX90316无接触旋转定位解决方案

Melexis 公司的MLX90316是CMOS霍尔传感器IC,能给出并行于IC表面的磁场角度位置,应用在汽车和工业领域的无接触旋转定位. MLX90316具有高达360度的可编程角度范围,可编程的线性传输特性,可选择模拟,PWM和串行协议控制,12位的角度分辨率和40位ID号码.本文介绍了MLX90316的主要特性, 模拟和PWM的方框图以及串行协议的方框图, 应用电路图,SOIC8和TSSOP16封装的MLX90316连接图, SPI型的单芯片与双芯片的应用框图和单芯片串行协议模式应用框图.

MLX90316: Rotary Position Sensor IC

The MLX90316 is a CMOS Hall sensor that gives the angular position of a magnetic field parallel to the IC surface. It is designed for contactless rotary position sensors that are frequently required in both automotive and industrial applications. The MLX90316 detects the absolute angular position of a small magnet (diametrally magnetized) that is positioned and rotates above the device surface.

An Integrated Magneto-Concentrator (IMC) concentrates the applied magnetic flux density parallel to the IC surface. At the boundaries of the IMC structure, an orthogonal component proportional to the applied flux density can be measured by two pairs of conventional planar Hall plates located orthogonally under the IMC and for each of the two directions parallel with the IC surface (X and Y). The first part of the sensor encodes a mechanical angle into two sinusoidal signals with 90° phase shift(sine and cosine). The two signals (Vx & Vy) proportional to the magnetic field are amplified, sampled and converted in the digital domain. The digital representations of the two signals are then used to calculate the angle through an Arctangent function applied on the ratio Vy/Vx. The Arctangent function is implemented by a look-up table.

The current angle value represented by a digital value can be converted back into the analog domain through a D/A converter. However, the output signal can either be an analog signal, a PWM signal or a Serial Protocol digital signal. The output transfer characteristic is fully programmable (e.g. offset, gain, clamping levels). The typical application of the MLX90316 is highlighted on the above figure. The MLX90316 can sense a rotary position without contact and over a wide range up to 360º (complete revolution).

MLX90316主要特性和优势:

Absolute Rotary Position Sensor IC

Simple & Robust Magnetic Design

Tria⊗is™ Hall Technology

Programmable Angular Range up to 360 Degrees

Programmable Linear Transfer Characteristic

Selectable Analog (Ratiometric), PWM, Serial Protocol

12 bit Angular Resolution - 10 bit Angular Thermal Accuracy

40 bit ID Number

Single Die – SO8 Package RoHS Compliant

Dual Die (Full Redundant) – TSSOP16 Package RoHS Compliant

MLX90316应用:

Absolute Rotary Position Sensor Steering Wheel Position Sensor

Pedal Position Sensor Motor-shaft Position Sensor

Throttle Position Sensor Float-Level Sensor

Ride Height Position Sensor Non-Contacting Potentiometer

图1.MLX90316方框图(模拟和PWM)

图2.MLX90316方框图(串行协议)

图3.SOIC8封装的MLX90316连接图

图4.TSSOP16封装的MLX90316连接图(双芯片)

图5.PWM低侧输出配置连接图

图6.MLX90316 SPI型 – 单芯片应用框图

图7.MLX90316 SPI型– 双芯片应用框图

图8.MLX90316单芯片串行协议模式应用框图

The EVB_MLX90316DC consists into a Printed Circuit Board (PCB) and Magnetic Knob.

The PCB implements the recommended application diagram from the MLX90316 datasheet. The MLX90316DC (SOIC-8) is mounted on the board. It also includes an aluminum ring in order to center the magnetic knob (see below) above the sensitive area of MLX90316. By default, the output transfer characteristic is programmed to get a 10%Vdd ... 90%Vdd analog output swing for 0 … 360 Degrees travel (complete revolution).

The magnetic knob features a small SmCo magnet diametrally magnetized D6H2.5 (Diameter = 6 mm and Height = 2.5 mm).

图9.MLX90316应用框图