ADT75 Analog Devices, Inc., ADT75 Datasheet - Page 12

• Manufacturer Part Number: ADT75
• Description: ?1?c Accurate, 12-bit Digital Temperature Sensor
• Manufacturer: Analog Devices, Inc.

ADT75
ONE-SHOT MODE
Setting Bit D5 of the configuration register enables the one-shot
mode. When this mode is enabled, the ADT75 goes immedi-
ately into shutdown mode and the current consumption is
reduced to typically 3 μA when V
V
when Address 0x04 is written to the address pointer register,
which is writing to the one-shot register. The ADT75 powers
up, does a temperature conversion, and powers down again.
Wait for a minimum of 60 ms after writing to the one-shot
register before reading back the temperature. This time ensures
the ADT75 has time to power up and do a conversion. Reading
back from the one-shot register, Address 0x04, gives the resultant
temperature conversion. Reading from the temperature value
register also gives the same temperature value.
When either of the overtemperature detection modes is
selected, a write to the one-shot register, Address 0x04, causes
the OS/ALERT pin to go active if the temperature exceeds the
overtemperature limits. Refer to Figure 12 for more information
on one-shot OS/ALERT pin operation.
Note: In the interrupt mode, a read from any register resets the
OS/ALERT pin after it is activated by a write to the one-shot
register. In the comparator mode, once the temperature drops
below the value in the T
register resets the OS/ALERT pin.
The one-shot mode is useful when one of the circuit design
priorities is to reduce power consumption.
DD
is 5 V. A one-shot temperature measurement is initiated
HYST
register, a write to the one-shot
DD
is 3.3 V and 5.5 μA when
Rev. 0 | Page 12 of 24
POLARITY = ACTIVE HIGH
POLARITY = ACTIVE HIGH
FAULT QUEUE
Bit D3 and Bit D4 of the configuration register are used to set
up a fault queue. Up to six faults are provided to prevent false
tripping of the OS/ALERT pin when the ADT75 is used in a
noisy temperature environment. The number of faults set in the
queue must occur consecutively to set the OS/ALERT output.
POLARITY = ACTIVE LOW
POLARITY = ACTIVE LOW
(COMPARATOR MODE)
(COMPARATOR MODE)
(INTERRUPT MODE)
(INTERRUPT MODE)
OS/ALERT PIN
OS/ALERT PIN
OS/ALERT PIN
OS/ALERT PIN
Figure 12. One-Shot OS/ALERT Pin Operation
TEMPERATURE
82°C
81°C
80°C
79°C
78°C
77°C
76°C
75°C
74°C
73°C
1
2
READ FROM ANY REGISTER.
THERE IS A 60ms DELAY BETWEEN WRITING TO THE
ONE-SHOT REGISTER AND THE OS/ALERT PIN GOING
ACTIVE. THIS IS DUE TO THE CONVERSION TIME.
WRITE TO
0x04 REG.
READ
2
1
WRITE TO
0x04 REG.
READ
2
1
WRITE TO
0x04 REG.
READ
2
1
T
T
TIME
OS
HYST