ADIS16003

Rev. 0 | Page 14 of 16

APPLICATIONS

DUAL-AXIS TILT SENSOR

PREHEAT

CRITICAL ZONE

TIME

RAMP-DOWN

RAMP-UP

One of the most popular applications of the ADIS16003 is tilt

measurement. An accelerometer uses the force of gravity as an

input vector to determine the orientation of an object in space.

An accelerometer is most sensitive to tilt when its sensitive axis

is perpendicular to the force of gravity, that is, parallel to the

earth’s surface. At this orientation, its sensitivity to changes in

tilt is highest. When the accelerometer is oriented on axis to

gravity, near its +1 g or –1 g reading, the change in output

acceleration per degree of tilt is negligible. When the acceler-

ometer is perpendicular to gravity, its output changes nearly

17.5 mg per degree of tilt. At 45°, its output changes at only

12.2 mg per degree, and resolution declines.

Figure 24. Acceptable Solder Reflow Profiles

Table 11.

Converting Acceleration to Tilt

Condition

When the accelerometer is oriented so both its x-axis and y-axis

are parallel to the earth’s surface, it can be used as a 2-axis tilt

sensor with a roll axis and a pitch axis. Once the output signal

from the accelerometer has been converted to an acceleration

that varies between –1 g and +1 g, the output tilt in degrees is

calculated as follows:

Be sure to account for overranges. It is possible for the

accelerometers to output a signal greater than ±1 g due to

vibration, shock, or other accelerations.

SECOND-LEVEL ASSEMBLY

The ADIS16003 may be attached to the second-level assembly

board using SN63 (or equivalent) or lead-free solder. Figure 24

and Table 11 provide acceptable solder reflow profiles for each

solder type. Note: These profiles may not be the optimum

profile for the user’s application. In no case should 260°C be

exceeded. It is recommended that the user develop a reflow

profile based upon the specific application. In general, keep in

mind that the lowest peak temperature and shortest dwell time

above the melt temperature of the solder results in less shock

and stress to the product. In addition, evaluating the cooling

rate and peak temperature can result in a more reliable

assembly.

Profile Feature

Sn63/Pb37

Pb-free

3°C/sec max

3°C/sec max

Preheat

100°C

150°C

150°C

200°C

60 sec to

120 sec

60 sec to

150 sec

Ramp-Up Rate

3°C/sec

3°C/sec

Time Maintained Above

183°C

217°C

60 sec to

150 sec

60 sec to

150 sec

Peak Temperature (T )

240°C +

0°C/–5°C

260°C +

0°C/–5°C

P

10 sec to

30 sec

20 sec to

40 sec

Time Within 5°C of Actual Peak

Ramp-Down Rate

6°C/sec max

6°C/sec max

Time 25°C to Peak Temperature

6 min max

8 min max