mlx90251 Melexis Company, mlx90251 Datasheet - Page 11

• Manufacturer Part Number: mlx90251
• Description: Programmable Linear Hall Effect Sensor
• Manufacturer: Melexis Company

The slope transfer characteristic defines the Sensitivity. The INVERT parameter changes the Sensitivity's
polarity, or the slope's direction. This allows the device to accommodate the application requirements and
the magnet's polarity. The slope is inverted in the first stage of the IC, at the Hall plate. With INVERT set to 0,
the output voltage increases as a South magnetic field is applied and decreases in the presence of a North
magnetic field. An INVERT value of 1 causes the output voltage to increase in the presence of a North
magnetic field and decrease in the presence of a South magnetic field.
referenced to the field component perpendicular to the top-face of the MLX90251.
Two independent values, called the clamping levels, can limit the output voltage range or swing. The
CLAMPLOW parameter adjusts the minimum output voltage level, ClampLo. The CLAMPHIGH sets the
maximum output voltage level, ClampHi. Both parameters have 10 bits of adjustment with a resolution of
approximately 0.005V. The formulas below give a close approximation of the output clamp voltage. The
actual clamping level formulas vary slightly from chip to chip. If CLAMPLOW exceeds CLAMPHIGH the
output voltage is fixed at the high clamp voltage level. The CLAMPHIGH and CLAMPLOW have an initial
value of 512, set by Melexis. This results in a fixed output voltage of approximately 50% V
At the point the output voltage switches between the linear operating region and the clamping region the
output can deviate slightly. This is represented by the grey areas in the figure below. The limits for deviation
in the Y axis are listed in Table 10. The deviation in the X axis is calculated from the application's transfer
function. The Clamp Comparator Offset does not affect the output linearity or clamp voltage accuracy.
During calibration it is recommended to set the clamp voltage outside of the transition region (0V to 5V).
Figure 10.6 Output Voltage Clamping Deviation
DC operating parameters at V
range (E or L).
Table 10: Clamp Comparator Offset Specification
3901090251
Rev 009
Parameter
10.5 Sensitivity Polarity (INVERT)
10.6 Clamping Levels (CLAMPLOW, CLAMPHIGH)
ClampLo
ClampHi
=
=
. 5
. 5
1023
1023
10
10
V
V
CLAMP HIGH
CLAMP LOW
∗
∗
Symbol
CLAMP
DD
CLAMPHIGH
VOUT
CLAMPLOW
= 5V (unless otherwise specified) and for T
OFF
Test Conditions
Linear Operating
V
V
Page 11 of 22
DD
Region
DD
Programmable Linear Hall Effect Sensor
=
=
. 5
. 5
00
00
V
V
Transition Point
Min
A
as specified by the temperature
The magnetic field polarity is
FIELD
Typical Max
MLX90251
DD
.
Data Sheet
Nov/06
Units