IC-MA3 Datasheet, PDF (14/19 Pages) IC-Haus GmbH – ANGULAR HALL SENSOR

iC-MA3 ANGULAR HALL SENSOR
WITH SIN/COS OUTPUT, CASCADABLE
POWER SAVING OPERATION
Rev A2, Page 14/19
A power saving mode reduces the current consumption
of the IC. There are three modes available, according
to Table 5, Page 9.
The power saving modes vary the time between two
active phases of the Hall sensors (Figure 8). M1 is the
constant current consumption without power saving;
the Hall sensors are active permanently.
Using power saving, the Hall sensors are activated only
for time t()on, and are deactivate for time t()off. This
yields a current consumption shown as M2.
The
ratio
of
t()on
t()on+t()off
is
the
value
listed
under
column
Update Rate in Table 5.
I(VDD)
I(VDD)on
M1
I(VDD)off
M2
As the Hall sensors are not permanently active, the per-
missible maximum rotary frequency reduces according
to the given ratio. Note that the IC’s current consump-
tion does not reduce by the same ratio, as only the Hall
sensors are deactivated and the current consumption
is still higher than during standby.
A power saving mode (selected by pin PSEL) can be
freely combined with any speed mode (selected by pin
FSEL).
Power savings are obtained by a lower sampling rate
for measurements, whereas speed settings change the
integration time by additional filtering. Both modes op-
erate independently from each another, but both take
influence on the permissible maximum rotary frequency.
If combining the modes, the permissible maximum ro-
tary frequency reduces according to the product of the
factors given by Tables 5 and 6.
Example
The reduced power mode (PSEL = low) reduces by a
factor of 6, the minimal speed setting (FSEL = open) by
a factor of 20. Thus, the combination reduces the per-
missible maximum rotary frequency from 60,000 rpm
to 500 rpm.
t()on
t()off
t
Figure 8: Current consumption with power saving