1.0 Functional Description (Continued)
1.11 POINTER REGISTER
(Selects which registers will be read from or written to):
P7
P6
P5
P4
P3
P2
P1
Register
Select
P0
0
0
0
0
0
0
P0-P1: Register Select:
P1
0
P0
Register
0
1
0
1
Temperature (Read only) (Power-up default)
Configuration (Read/Write)
THYST (Read/Write)
0
1
1
TOS (Read/Write)
P2–P7: Must be kept zero.
1.12 TEMPERATURE REGISTER
(Read Only):
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MSB Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
LSB
X
X
X
X
X
X
X
D0–D6: Undefined
D7–D15: Temperature Data. One LSB
complement format.
=
0.5˚C. Two’s
1.13 CONFIGURATION REGISTER
(Read/Write):
D7
D6
D5
D4
D3
D2
D1
Cmp/Int
D0
Shutdown
0
0
0
Fault Queue
O.S.
Polarity
Power up default is with all bits “0” (zero).
D3–D4: Fault Queue: Number of faults necessary to detect
before setting O.S. output to avoid false tripping due to
noise. Faults are determind at the end of a conversion.
Conversions take about 100 ms, typically, to complete.
D0: Shutdown: When set to 1 the LM75 goes to low power
shutdown mode.
D1: Comparator/Interrupt mode: 0 is Comparator mode, 1 is
Interrupt mode.
D2: O.S. Polarity: 0 is active low, 1 is active high. O.S. is an
open-drain output under all conditions.
D4
0
D3
0
Number of Faults
1 (Power-up default)
0
1
2
4
6
1
0
1
1
D5–D7: These bits are used for production testing and must
be kept zero for normal operation.
1.14 THYST AND TOS REGISTER
(Read/Write):
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MSB Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
LSB
X
X
X
X
X
X
X
D0–D6: Undefined
D7–D15: THYST Or TOS Trip Temperature Data. Power up
default is TOS = 80˚C, THYST = 75˚C.
11
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