AK8975 Datasheet, PDF (11/34 Pages) Asahi Kasei Microsystems – 3-axis Electronic Compass

[AK8975/C]
6. Functional Explanation
6.1. Power States
When VDD and VID are turned on from Vdd=OFF (0V) and Vid=OFF (0V), all registers in AK8975/C are
initialized by POR circuit and AK8975/C transits to Power-down mode.
All the states in the table below can be set, although the transition from state 2 to state 3 and the transition from
state 3 to state 2 are prohibited.
States VDD
1 OFF (0V)
2 OFF (0V)
3 2.4V to 3.6V
4 2.4V to 3.6V
VID
OFF (0V)
1.65V to 3.6V
OFF (0V)
1.65V to Vdd
Power states
OFF (0V).
SCL, SDA should be fixed to the voltage that does
not exceed 3.6V. Other digital pins should be fixed
to L(0V).
OFF (0V). It doesn’t affect external interface.
OFF (0V). It consumes current same as
Power-down mode.
SCL, SDA should be fixed to the voltage that does
not exceed 3.6V. Other digital pins should be fixed
to L (0V).
ON
Table 6.1
6.2. Reset Functions

AK8975/C has two types of reset;
(1) Power on reset (POR)
When Vdd reaches approximately 2V (reference value for design), POR circuit operates, and AK8975/C
is reset.
(2) VID monitor
When Vid is turned OFF (0V), AK8975/C is reset.
When AK8975/C is reset, all registers are initialized and AK8975/C transits to Power-down mode.
MS1187-E-02
- 11 -
2010/05