LM95172EWG10A NSC [National Semiconductor], LM95172EWG10A Datasheet - Page 11

• Manufacturer Part Number: LM95172EWG10A
• Manufacturer: NSC [National Semiconductor]

1.2 ONE SHOT CONVERSION
The LM95172EWG features a one-shot conversion bit, which
is used to initiate a singe conversion and comparison cycle
when the LM95172EWG is in shutdown mode. While the
LM95172EWG is in shutdown mode, writing a "1" to the One-
Shot bit in the Control/Status Register will cause the
LM95172EWG to perform a single temperature conversion
and update the Temperature Register and the affected status
bits. Operating the LM95172EWG in this one-shot mode al-
lows for extremely low average-power comsumption, making
it ideal for low-power applications.
When the One-shot bit is set, the LM95172EWG initiates a
temperature conversion. After this initiation, but before the
completion of the conversion, and resultant register updates,
the LM95172EWG is in a "one-shot" state. During this state,
the Data Available (DAV) flag in the Control/Status Register
is "0" and the Temperature Register contains the value 8000h
The OVERTEMP Output will assert when the measured tem-
perature is greater than the T
reset if any of the following events happen:
1. The temperature falls below the value stored in the T
register, or
2. A "1" is written to the OVERTEMP Reset bit in the Control/
Status Register.
FIGURE 9. LM95172EWG OVERTEMP vs. Temperature Response Diagram
HIGH
value. OVERTEMP will
LOW
11
(-256°C). All other registers contain the data that was present
before initiating the one-shot conversion. After the tempera-
ture measurement is complete, the DAV flag will be set to "1"
and the temperature register will contain the resultant mea-
sured temperature.
1.3 OVERTEMP OUTPUT
The Over-temperature (OVERTEMP) output is a temperature
switch signal that indicates when the measured temperature
exceeds the T
T
register is used to set the hysteresis. The T
sets the temperature below which the OVERTEMP output re-
sets. The OVERTEMP output of the LM95172EWG behaves
as a temperature comparator. The following explains the op-
eration of OVERTEMP. Figure 9 illustrates the OVERTEMP
output behavior.
If OVERTEMP is cleared by the master writing a "1" to the
OVERTEMP Reset bit while the measured temperature still
exceeds the T
the completion of the next temperature conversion. Placing
the LM95172EWG in shutdown mode or triggering a one-shot
conversion does not cause OVERTEMP to reset.
HIGH
register sets the high temperature limit and the T
HIGH
HIGH
value, OVERTEMP will assert again after
programmed limit. The programmable
30076621
LOW
register also
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LOW