AK8963N Datasheet, PDF (12/38 Pages) Asahi Kasei Microsystems – 3-axis Electronic Compass

[AK8963]
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 AK8963 are
initialized by POR circuit and AK8963 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.
Table 6.1
State VDD
VID
Power state
1 OFF (0V)
OFF (0V)
OFF (0V).
It doesn’t affect external interface. Digital input
pins other than SCL and SDA pin should be fixed
to “L”(0V).
2 OFF (0V)
1.65V to 3.6V OFF (0V). It doesn’t affect external interface.
3 2.4V to 3.6V OFF (0V)
OFF (0V).
It doesn’t affect external interface. Digital input
pins other than SCL and SDA pin should be fixed
to “L” (0V).
4 2.4V to 3.6V 1.65V to Vdd ON
6.2. Reset Functions
When the power state is ON, always keep Vid≤Vdd.
Power-on reset (POR) works until Vdd reaches to the operation effective voltage (about 1.4V: reference value
for design) on power-on sequence. After POR is deactivated, all registers are initialized and transits to power
down mode.
When Vdd=2.4 ~ 3.6V, POR circuit and VID monitor circuit are active. When Vid=0V, AK8963 is in reset
status and it consumes the current of reset state (IDD4).
AK8963 has four types of reset;
(1) Power on reset (POR)
When Vdd rise is detected, POR circuit operates, and AK8963 is reset.
(2) VID monitor
When Vid is turned OFF (0V), AK8963 is reset.
(3) Reset pin (RSTN)
AK8963 is reset by Reset pin. When Reset pin is not used, connect to VID.
(4) Soft reset
AK8963 is reset by setting SRST bit.
When AK8963 is reset, all registers are initialized and AK8963 transits to Power-down mode.
MS1356-E-02
- 12 -
2013/10