MLX90333

Triaxis 3D-Joystick Position Sensor

3901090333

Page 21 of 38

Data Sheet

Rev. Preliminary

May 07

α

β

x

y

z

14.3.2. Alpha/Beta Discontinuity Point (or Zero Degree Point)

The Discontinuity Point defines the zero point of the circle (Alpha or Beta). The discontinuity point places

the origin at any location of the trigonometric circle (see Figure 12).

For a Joystick Application, Melexis recommends to set the DP to zero.

14.3.3. LNR Parameters

The LNR parameters, together with the clamping values, fully define the relation (the transfer function)

between the digital angles (Alpha and Beta) and the output signals.

The shape of the MLX90333 transfer function from the digital angle values to the output voltages is

described by the drawing below (See Figure 11). Four segments can be programmed but the clamping

levels are necessarily flat.

Alpha

ALPHA_S1

ALPHA_S0

360°

Clamping Low

Clamping High

ALPHA_X

ALPHA_Y

CLAMPHIGH

CLAMPLOW

0%

100%

0°

B

A

C

Figure 11 - Digital Angle (Alpha) Transfer Characteristic (Idem ditto for Beta)