AK9720 Datasheet, PDF (14/31 Pages) Asahi Kasei Microsystems – IR Sensor Module with I2C I/F

[AK9720]
Functional Descriptions
1. Power Supply State
When V_DD and DVDD turn on from the state of V_DD = OFF (0V) and DVDD = OFF (0V),
power on reset (POR) is automatice all registers will be initialized, and the AK9720 will shift
to Power down Mode.
Although all states of the following table can exist, the changes to state 3 from state 2 and
the changes to state 2 from state 3 are prohibited.
State
1
V_DD
OFF (0V)
2
OFF (0V)
3
1.71 to 3.63V
4
1.71 to 3.63V
DVDD
OFF(0V)
1.65 to 3.63V
OFF(0V)
1.65V to V_DD
Power Supply State
OFF (0V)
I2C bus is open.
OFF (0V)
I2C bus is open.
INT pin = Low Level
*This is not the recommended operational
condition.
OFF (0V).
The current consumption is as same as
Power down Mode.
I2C bus is open.
ON
2. Reset Function
When the power supply is in an ON state, set up DVDD lower than V_DD (DVDD<=V_DD) .
Power-on reset (POR) works until V_DD reaches the operating voltage (about 1.4V: design
reference). After POR, all registers are set to initial values, and Power down Mode is
selected.
When VDD is between 1.71V and 3.63V, POR circuit and DVDD monitor circuit are
operational. When DVDD=0V, the current consumption is identical to as Reset State,
because AK9720 is in Reset State.
AK9720 has three reset functions.
(1) Power-on Reset (POR)
POR circuit resets AK9720 by detecting VDD rising.
(2)DVDD Monitor
When DVDD is in OFF (0V), AK9720 is reset.
(3)Soft Reset
When the SRST bit is set, AK9720 is reset.
When AK9720 is reset, all registers are set to initial values, and Power down Mode is
selected.
Rev.02
AKM Confidential
- 14 -
2012/11