ADT7516ARQ(RevA) Просмотр технического описания (PDF) - Analog Devices
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Компоненты Описание
производитель
ADT7516ARQ
(Rev.:RevA)
(Rev.:RevA)
Analog Devices
ADT7516ARQ Datasheet PDF : 44 Pages
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ADT7516/ADT7517/ADT7519
I
N×I
IBIAS
VDD
INTERNAL
SENSE
TRANSISTOR
BIAS
DIODE
VOUT+
TO ADC
VOUT–
Figure 46. Top Level Structure of Internal Temperature Sensor
Table 7. Thermal Voltage Output (0 V to 2VREF)
O/P Voltage (V)
Default °C Max °C Sample °C
0
–40
–128
0
0.25
–26
–114
+14
0.5
+12
–100
+28
0.75
+3
–85
+43
1
+17
–71
+57
1.12
+23
–65
+63
1.47
+43
–45
+83
1.5
+45
–43
+85
2
+73
–15
+113
2.25
+88
0
+127
2.5
+102
+14
UDB∗
2.75
+116
+28
UDB∗
3
UDB∗
+42
UDB∗
3.25
UDB∗
+56
UDB∗
3.5
UDB∗
+70
UDB∗
3.75
UDB∗
+85
UDB∗
4
UDB∗
+99
UDB∗
4.25
UDB∗
+113
UDB∗
4.5
UDB∗
+127
UDB∗
Negative temperatures:
( ) Offset Register Code(d) = 0 V Temp + 128
where:
D7 of Offset Register Code is set to 1 for negative temperatures.
Example:
Offset Register Code(d) = (− 40) + 128 = 88d = 58h
Since a negative temperature has been inserted into the
equation, DB7 (MSB) of the offset register code is set to 1.
Therefore 58h becomes D8h.
58h + DB7(1) = D8h
Positive temperatures:
Offset Register Code (d) = 0 V Temp
Example:
Offset Register Code (d) = 10d = 0Ah
The following equation is used to work out the various
temperatures for the corresponding 8-bit DAC output:
8 − Bit Temp= (DAC O / P ÷1LSB)+ (0V Temp)
For example, if the output is 1.5 V, VREF-IN = 2.25 V, 8-bit DAC
has an LSB size = 2.25 V/256 = 8.79 × 10–3, and 0 V temp is at
–128°C, then the resultant temperature is
( ) 1.5 ÷ 8.79×10−3 + (−128) = +43°C
The following equation is used to work out the various
temperatures for the corresponding 10-bit DAC output:
10-Bit Temp = ((DAC O/P ÷ 1 LSB) × 0.25) + (0 V Temp)
For example, if the output is 0.4991 V, VREF-IN = 2.25 V, 10-bit
DAC has an LSB size = 2.25 V/1024 = 2.197 × 10–3, and 0 V
temp is at –40°C, then the resulting temperature is
(((0.4991 ÷ 2.197 × 10–3) × 0.25) + (–40) = +16.75°C
Figure 47 shows a graph of the DAC output versus temperature
for a VREF-IN = 2.25 V.
2.25
2.10
1.95
1.80
0V = –128°C
1.65
1.50
1.35
0V = –40°C
1.20
1.05
0.90
0.75
0.60
0V = 0°C
0.45
0.30
0.15
0
–128–110 –90 –70 –50 –30 –10 10 30 50 70 90 110 127
TEMPERATURE (°C)
Figure 47. DAC Output vs. Temperature VREF-IN = 2.25 V
Rev. A | Page 22 of 44
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