Datasheet

STLM75 Functional description
Doc ID 13296 Rev 12 19/40
3.1.5 Hysteresis temperature register (T
HYS
)
T
HYS
register is a two-byte (16-bit) READ/WRITE register that stores the user-
programmable lower trip-point temperature for the thermal alarm in two’s complement
format (see Ta bl e 8 ). This register defaults to 75 °C at power-up (i.e., 0100 1011 0000
0000).
The format of this register is the same as that of the temperature register. The MSB position
contains the sign bit for the digital temperature and bit14 contains the temperature MSB.
Note: These are comparable formats to the DS75 and LM75.
3.2 Power-up default conditions
The STLM75 always powers up in the following default states:
● Thermostat mode = comparator mode
● Polarity = active-low
● Fault tolerance = 1 fault (i.e., relevant bits set to '0' in the configuration register)
● T
OS
= 80 °C
● T
HYS
= 75 °C
● Register pointer = 00 (temperature register)
Note: After power-up these conditions can be reprogrammed via the serial interface.
Table 8. T
OS
and T
HYS
register format
Bytes HS byte LS byte
Bits
MSB TMSB TLSB LSB
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
STLM75 SB TMSB TD TD TD TD TD TD
9-bit
TLSB
000000 0
Keys: SB = two’s complement sign bit
TMSB = temperature MSB
TLSB = temperature LSB
TD = temperature data