KMI17_4

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© NXP Semiconductors N.V. 2014. All rights reserved.

Product data sheet

Rev. 1 — 1 September 2014

8 of 16

NXP Semiconductors

KMI17/4

Rotational speed sensor

[1]

[2]

indicates stable operation.

[3]

Module m of the gear wheel is defined as the ratio of outer diameter D and number of teeth N: m = D/N.

[4]

RMS value measured as spread of the delay between zero-crossing of the magnetic field and output of the associated speed pulse.

Extra jitter is possible due to disturbances on the supply line and other non-ideal conditions.

Period jitter with ideal ferromagnetic encoder with a module[3] of 2.1 mm minimum and track width = 10 mm. The sensor

reading point is located within a distance x of

1 mm next to the center of the encoder track; see Figure 6

(T)

period jitter

low-field; RMS value;

due to noise at large air

gaps; H in y direction

=500 A/m

[4] --0.5

%

high-field; RMS value;

due to noise; H in

y direction = 2500 A/m;

[4] --0.1

%

Air gap with ideal ferromagnetic encoder with a module[3] of 2.1 mm minimum and track width = 10 mm. The sensor reading

point is located within a distance x of

1 mm next to the center of the encoder track; see Figure 6

start-up air gap of encoder wheel

to sensor surface

after power-on;

at start-up of encoder

wheel

0.5

-

2.4

mm

d

air gap of encoder wheel to

sensor surface

in normal mode after

10 wheel rotations

0.5

-

2.8

mm

Customer Production Test Mode (CPTM)

zero offset supply voltage

16

15.5

15

V

LOW-level supply current

4.0

3.5

-

mA

HIGH-level supply current

8.4

7

6.02

mA

H/V

CC

magnetic field strength variation

with supply voltage

see Figure 5

50

52

56

(A/m)/V

Table 6.

otherwise specified.

Symbol

Parameter

Conditions

Min

Typ

Max

Unit

Fig 6.

Sensor positioning