DS75S+/ Maxim Integrated Products, DS75S+/ Datasheet - Page 7

• Manufacturer Part Number: DS75S+/
• Description: Board Mount Temperature Sensors
• Manufacturer: Maxim Integrated Products

Specifications of DS75S+/

• Temperature Threshold: Programmable
• Full Temp Accuracy: +/- 2 C
• Package / Case: SOIC-8
• Digital Output - Bus Interface: 2-Wire, SMBus
• Digital Output - Number Of Bits: 9 bit to 12 bit
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Output Type: Digital
• Supply Current: 1000 uA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Figure 3. TEMPERATURE, T
Table 3. 12-BIT RESOLUTION TEMPERATURE/DATA RELATIONSHIP
SHUTDOWN MODE
For power-sensitive applications, the DS75 offers a low-power shutdown mode. The SD bit in the
configuration register controls shutdown mode. When SD is changed to 1, the conversion in progress
will be completed and the result stored in the temperature register after which the DS75 will go into a
low-power standby state. The O.S. output will be cleared if the thermostat is operating in interrupt mode
and O.S will remain unchanged in comparator mode. The 2-wire interface remains operational in
shutdown mode, and writing a 0 to the SD bit returns the DS75 to normal operation.
OPERATION–THERMOSTAT
The DS75 thermostat has two operating modes, comparator mode and interrupt mode, which activate and
deactivate the open-drain thermostat output (O.S.) based on user-programmable trip-points (T
T
with the over-temperature trip-point (T
register set to 75°C. If these power-up settings are compatible with the application, the DS75 can be used
as a standalone thermostat (i.e., no 2–wire communication required). If interrupt mode operation, active-
high O.S. polarity or different T
up, so standalone operation is not possible.
In both operating modes, the user can program the thermostat fault tolerance, which sets how many
consecutive temperature readings (1, 2, 4, or 6) must fall outside of the thermostat limits before the
thermostat output is triggered. The fault tolerance is set by the F1 and F0 bits in the configuration and at
power-up the fault tolerance is 1.
The data format of the T
3), i.e., a two-byte two’s complement representation of the trip-point temperature in degrees centigrade
with bits 3 through 0 hardwired to 0. After every temperature conversion, the measured temperature is
HYST
MS Byte
LS Byte
). The DS75 powers up with the thermostat in comparator mode with active-low O.S. polarity and
bit 15
TEMPERATURE
bit 7
2
S
-1
+25.0625
-25.0625
+10.125
-10.125
+125
+0.5
(°C)
-0.5
-55
0
OS
bit 14
and T
bit 6
2
2
-2
6
OS
HYST
and T
H
registers is identical to that of the temperature register (see Figure
, and T
bit 13
bit 5
DIGITAL OUTPUT
0111 1101 0000 0000
0001 1001 0001 0000
0000 1010 0010 0000
0000 0000 1000 0000
0000 0000 0000 0000
1111 1111 1000 0000
1111 0101 1110 0000
1110 0110 1111 0000
1100 1001 0000 0000
2
2
OS
HYST
-3
5
) register set to 80°C and the hysteresis trip-point (T
(BINARY)
values are desired, they must be programmed after power-
L
REGISTER FORMAT
7 of 14
bit 12
bit 4
2
2
-4
4
bit 11
bit 3
2
0
3
DIGITAL OUTPUT
(HEX)
7D00h
0A20h
FF80h
F5E0h
E6F0h
C900h
1910h
0080h
0000h
bit 10
bit 2
2
0
2
bit 9
bit 1
2
0
1
OS
bit 8
bit 0
HYST
2
DS75
0
0
and
)