TEMPERATURE
(°C)
128
127.9375
100
80
75
50
25
0.25
0.0
–0.25
–25
–55
–128
DIGITAL OUTPUT
(BINARY)
0111
0111
0110
0101
0100
0011
0001
0000
0000
1111
1110
1100
1000
1111
1111
0100
0000
1011
0010
1001
0000
0000
1111
0111
1001
0000
1111
1111
0000
0000
0000
0000
0000
0100
0000
1100
0000
0000
0000
HEX
7FF
7FF
640
500
4B0
320
190
004
000
FFC
E70
C90
800
Measured
Temperature
T
HIGH
T
LOW
TMP75/TMP175
ALERT PIN
(Comparator Mode)
POL = 0
TMP75/TMP175
ALERT PIN
(Interrupt Mode)
POL = 0
TMP75/TMP175
ALERT PIN
(Comparator Mode)
POL = 1
TMP75/TMP175
ALERT PIN
(Interrupt Mode)
POL = 1
TABLE V. Temperature Data Format.
The user can obtain 9, 10, 11, or 12 bits of resolution by
addressing the Configuration Register and setting the reso-
lution bits accordingly. For 9-, 10-, or 11-bit resolution, the most
significant bits in the Temperature Register are used with the
unused LSBs set to zero.
Read
Read
Time
Read
CONFIGURATION REGISTER
The Configuration Register is an 8-bit read/write register
used to store bits that control the operational modes of the
temperature sensor. Read/write operations are performed
MSB first. The format of the Configuration Register for the
TMP175 and TMP75 is shown in Table VI, followed by a
breakdown of the register bits. The power-up/reset value of
the Configuration Register is all bits equal to 0.
FIGURE 3. Output Transfer Function Diagrams.
FAULT QUEUE (F1/F0)
A fault condition is defined as when the measured tempera-
ture exceeds the user-defined limits set in the T
HIGH
and
T
LOW
Registers. Additionally, the number of fault conditions
required to generate an alert may be programmed using the
fault queue. The fault queue is provided to prevent a false
alert as a result of environmental noise. The fault queue
requires consecutive fault measurements in order to trigger
the alert function. If the temperature falls below T
LOW
, prior
to reaching the number of programmed consecutive faults
limit, the count is reset to 0. Table VII defines the number of
measured faults that may be programmed to trigger an alert
condition in the device.
Byte
1
D7
OS
D6
R1
D5
R0
D4
F1
D3
F0
D2
POL
D1
TM
D0
SD
TABLE VI. Configuration Register Format.
SHUTDOWN MODE (SD)
The Shutdown Mode of the TMP175 and TMP75 allows the
user to save maximum power by shutting down all device
circuitry other than the serial interface, which reduces current
consumption to typically less than 0.1µA. Shutdown Mode is
enabled when the SD bit is 1; the device will shut down once the
current conversion is completed. When SD is equal to 0, the
device will maintain a continuous conversion state.
F1
0
0
1
1
F0
0
1
0
1
CONSECUTIVE FAULTS
1
2
4
6
TABLE VII. Fault Settings of the TMP175 and TMP75.
THERMOSTAT MODE (TM)
The Thermostat Mode bit of the TMP175 and TMP75 indicates
to the device whether to operate in Comparator Mode (TM = 0)
or Interrupt Mode (TM = 1). For more information on comparator
and interrupt modes, see the section,
High and Low Limit
Registers.
CONVERTER RESOLUTION (R1/R0)
The Converter Resolution Bits control the resolution of the
internal Analog-to-Digital (A/D) converter. This allows the
user to maximize efficiency by programming for higher reso-
lution or faster conversion time. Table VIII identifies the
Resolution Bits and relationship between resolution and con-
version time.
CONVERSION TIME
(typical)
27.5ms
55ms
110ms
220ms
POLARITY (POL)
The Polarity Bit of the TMP175 and TMP75 allows the user
to adjust the polarity of the ALERT pin output. If POL = 0, the
ALERT pin will be active LOW, as shown in Figure 3. For
POL = 1, the ALERT Pin will be active HIGH, and the state
of the ALERT Pin is inverted.
R1
0
0
1
1
R0
0
1
0
1
RESOLUTION
9 Bits (0.5°C)
10 Bits (0.25°C)
11 Bits (0.125°C)
12 Bits (0.0625°C)
TABLE VIII. Resolution of the TMP175 and TMP75.
6
TMP175, 75
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