MLX90215 datasheet(9/10 Pages) MELEXIS

9 / 10 page

MLX90215

Precision Programmable

Linear Hall Effect Sensor

3901090215

Page 9

9/09/03

Rev 007

ApplicationNotes

LinearPrecisionCurrentSensor

The

Programmable

gain,

offset,

and

temperature

compensation of MLX90215 allows great flexiblity in

the design of a current sensor.

Current flowing through a conductor can produce a

proportional magnet field. The MLX90215 can then

produce an output voltage proportional to the current.

Using the programmable gain and offset function the

output of the MLX90215 can be adjusted to sense a

wide range of current allowing for a flexible design.

Slotted

Torroid

Example

Assuming

infinite

permeabilty of the core, the magnetic field through the

air gap produced by a single wire turn is given by

equation 2

Equation 2

Where: I = current in Amperes

B = magnetic field in Tesla

lg = length of air gap in Meters

uo = Permeability of free space (4

π10-7H/m)

This equation is a close estimate for the field in the air

gap, but does not take into account magnetic losses in

the core, fringing effects, and mechanical tolerances of

the air gap. The programmable MLX90215 can be

adjusted to compensate for these errors simplifying the

design. The temperature compensation of MLX90215

can also be adjusted to counteract temperature losses of

core.

For sensing a current ±100A, with an air gap of 2mm

equation 2 yields a magnetic field range of ±63mT. The

output range of the MLX90215 is 0.5V to 4.5V (4V full

scale). Equations 3a and 3b yield a sensitivity of 32mV/

mT and a Voq of 2.5V.

Equation 3

a) S = 4000mV/ 126mT

b) Voq = 4V/2 + 0.5V

The resulting gain of the current sensor is 20mV/A with

an offset of 2.5V. For best results it is recommend that

MLX90215 be programmed with a Voq of 50% Vdd 1/2

Vdd bit set.

Magnetic Suppliers:

Elna Ferrites Technologies Inc

Eastern Components

Fair Rite Products Corp

MLX90215 bảng dữ liệu(PDF) 9 Page - Melexis Microelectronic Systems

MLX90215 bảng dữ liệu(HTML) 9 Page - Melexis Microelectronic Systems

Html Pages

1 2 3 4 5 6 7 8 9 10

bảng dữ liệu tải về

Link URL