Datasheet

LM95172
www.ti.com SNOSB33B –DECEMBER 2009–REVISED MARCH 2013
Bit <15>: Shutdown (SD) Bit. Writing a “1” to this bit and holding it high for at least the specified maximum
conversion time, at the existing temperature resolution setting, enables the Shutdown Mode. Writing a “0” to this
bit restores the LM95172EWG to normal mode.
Bit <14>: One-Shot Bit. When in shutdown mode (Bit <15> is "1"), initiates a single temperature conversion and
update of the temperature register with new temperature data. Has no effect when in continuous conversion
mode (i.e., when Bit <15> is "0"). Always returns a "0" when read.
Bit <13>: OVERTEMP Reset Bit. Writing a "1" to this Bit resets the OVERTEMP Status bit and, after a possible
wait up to one temperature conversion time, the OVERTEMP pin. It will always return a "0" when read.
Bit <12>: Conversion Toggle Bit. Toggles each time the Control/Status register is read if a conversion has
completed since the last read. If conversion has not been completed, the value will be the same as last read.
Bit <11>: OVERTEMP Status Bit. This Bit is "0" when OVERTEMP output is low and "1" when OVERTEMP
output is high. The OVERTEMP output is reset under the following conditions: (1) Cleared by writing a "1" to the
OVERTEMP Reset Bit (Bit <13>) in this register or (2) Measured temperature falls below the T
LOW
limit. If the
temperature is still above T
HIGH
, and OVERTEMP Reset is set to "1", then the Bit and the pin clear until the next
conversion, at which point the Bit and pin would assert again.
Bit <10>: Temperature High (T
HIGH
) Flag Bit. This Bit is set to "1" when the measured temperature exceeds the
T
HIGH
limit stored in the programmable T
HIGH
register. The flag is reset to "0" when both of two conditions are
met: (1) temperature no longer exceeds the programmed T
HIGH
limit and (2) upon reading the Control/Status
Register. If the temperature no longer exceeds the T
HIGH
limit, the status Bit remains set until it is read by the
master so that the system can check the history of what caused the OVERTEMP to assert.
Bit <9>: Temperature Low (T
LOW
) Flag Bit. This Bit is set to "1" when the measured temperature falls below the
T
LOW
limit stored in the programmable T
LOW
register. The flag is reset to "0" when both of two conditions are met:
(1) temperature is no longer below the programmed T
LOW
limit and (2) upon reading the Control/Status Register.
If the temperature is no longer below, or equal to, the T
LOW
limit, the status Bit remains set until it is read by the
master so that the system can check the history of what caused the OVERTEMP to assert.
Bit <8>: Data Available (DAV) Status Bit. This Bit is "0" when the temperature sensor is in the process of
converting a new temperature. It is "1" when the conversion is done. It is reset after each read and goes high
again after one temperature conversion is done. In one-shot mode: after initiating a temperature conversion while
operating, this status Bit can be monitored to indicate when the conversion is done. After triggering the one-shot
conversion, the data in the temperature register is invalid until this Bit is high (i.e., after completion of the first
conversion).
Bit <7>: OVERTEMP Disable Bit. When set to "0" the OVERTEMP output is enabled. When set to "1" the
OVERTEMP output is disabled. This Bit also controls the OVERTEMP Status Bit (this register, Bit <11>) since
that Bit reflects the state of the OVERTEMP pin.
Bit <6>: OVERTEMP Polarity Bit. When set to "1", OVERTEMP is active-high. When "0" it is active-low.
Control/Status Register (Continued)
Bit <5:4>: Temperature Resolution Bits. Selects one of four user-programmable temperature data resolutions as
indicated in the following table.
Control/Status Register Resolution
Bit 5 Bit 4 Bits °C
0 0 13 0.0625
0 1 14 0.03125
1 0 15 0.015625
1 1 16 0.0078125
Bit <3>: Always write a zero to this Bit.
Bit <2:1>: Reserved Bits. Will return whatever was last written to them. Value is zero on power-up.
Bit <0>: Always write a zero to this Bit.
Reset State: 0000h
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