AK9750 Datasheet, PDF (14/49 Pages) Asahi Kasei Microsystems – IR Sensor IC with I2C I/F

[AK9750]
11.3 Operating Mode
11.3.1. Normal Mode/Switch Mode
AK9750 has two Modes, Normal Mode and Switch Mode.
Normal Mode is the mode which controls AK9750 by using I²C interface. The digital output the four IR
sensors and the internal temperature sensor can be used through the I²C interface in Normal Mode.
INT output also can be used.
Switch Mode is the mode which uses only INT output without using I²C interface. When the differential
output of two sensors (IR1 - IR3 / IR2 - IR4) exceeds the upper / lower thresholds which are set to
EEPROM, INT output turns “active”. When the differential output of two sensors (IR1 - IR3 / IR2 - IR4) is
in the range which is set to EEPROM, INT output is “non-active”. The hysteresis for the thresholds can
be set to EEPROM for avoiding the chattering of INT output. When Switch Mode is used, the threshold
and the hysteresis should be set to EEPROM beforehand. When the accuracy of HumanSensing is not
cared, Switch Mode can be used.
Normal Mode / Switch Mode selection is controlled by the CAD1 pin and CAD2 pin.
When CAD1 pin and CAD0 pin are set as CAD1 pin= CAD0 pin= “H”, the digital output can be used
through the I²C interface.
When CAD1 pin and CAD0 pin are set as CAD1 pin= CAD0 pin= “H”, Switch Mode is selected. When
Switch Mode is selected, SCL pin and SDA pin should be tied to “H”. (Do not access the AK9750 through
the I²C interface in Switch Mode.)
CAD1
0
0
1
1
Table 11.2. CAD0 / CAD1 pin Setting and Slave Address
CAD0
I²C output
Slave address
0
Enable
64H
1
Enable
65H
0
Enable
66H
1
Disable
(67H)
Mode
Normal Mode
Normal Mode
Normal Mode
Switch Mode
015002896-E-01
- 14 -
2015/10