Datasheet

12
Atmel AT30TSE002B [DATASHEET]
8711G–SEEPR–5/12
10.3 Temperature Sensor Power-on Default
The AT30TSE002B has an internal Power-On Reset (POR) circuit. When the supply voltage drops below the POR
threshold, the device will reset to the following power-on default conditions:
 Sensor starts monitoring temperature continuously.
 Address Pointer Register = 00h.
 Upper / Lower Alarm Trip registers and Crit_Alarm registers are set to 0°C.
 EVENT register cleared and pulled high by external pull up resistor.
 Operational mode is comparator.
 EVENT hysteresis is 0°C.
 SMBus register =00h.
10.4 Device Initialization
The AT30TSE002B Temperature Sensor has programmable registers that, upon device power-on, are initialized to zero.
Table 11-1 shows the Power-On register default values. The
EVENT output is defaulted to deasserted state and
comparator mode.
Note: The Upper Alarm Trip, Lower Alarm Trip, Critical Alarm Trip, and Configuration registers need to be
programmed to desired values before temperature sensor can properly function.
10.5 SMBus Timeout
The AT30TSE002B supports the SMBus timeout feature for temperature sensor operations if enabled via setting the
SMBus register (see Section 11.10). This feature helps prevent potential system bus hang-ups by resetting the serial
interface if SCL stays low for a time specified by the t
OUT
parameter. This requires a minimum SCL clock speed of 10Khz
as specified in the SMBus specification to avoid any timeout issues.