EVAL-ADT7462EBZ ON Semiconductor, EVAL-ADT7462EBZ Datasheet - Page 22

• Manufacturer Part Number: EVAL-ADT7462EBZ
• Description: BOARD EVALUATION FOR ADT7462
• Manufacturer: ON Semiconductor
• Type: Temperature Sensorr

Specifications of EVAL-ADT7462EBZ

• Contents: Evaluation Board
• For Use With/related Products: ADT7462
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Input Circuit
Figure 36. Each input circuit consists of an input protection
diode, an attenuator, plus a capacitor to form a first−order,
low−pass filter that gives the input immunity to high
frequency noise.
are divided so that the full−scale value equals the reference
(2.25 V). All analog inputs are multiplexed into the on−chip,
successive approximation ADC. This ADC has a resolution
of ten bits. The basic input range is from 0 V to 2.25 V, but
the inputs have built−in attenuators to allow measurement of
larger and smaller voltages. To allow a tolerance for these
voltages, the ADC produces an output of 3/4 full scale
(decimal 768 or 0x300) for the nominal input voltage and so
has enough headroom to cope with overvoltages.
input voltage is shown in Table 12.
Table 11. Voltage Inputs
Table 12. Input Range Code Conversion
Voltage (3/4 Scale)
The internal structure for the voltage inputs is shown in
Voltages with full−scale values greater than the reference
A list of corresponding LSB and full−scale values for each
V
CCP1
Nominal Input
V
are enabled
CCP1
Pin
13
15
19
21
22
23
24
25
26
28
29
7
8
+1.25V
, when VIDs
+3.3V
V
+2.5V
+1.8V
+1.5V
+1.2V
+0.9V
+12V
+5V
BATT
, V
CCP2
+12V1
+12V2
+3.3V
+2.5V / +1.8V
+1.25V / +0.9V
+5V
+12V3
V
V
+1.2V1 (G
+1.2V2 (FSB_V
+1.5V1 (ICH)
+1.5V2 (3GIO)
CCP1
CCP2
/ +1.5V / +1.8V / +2.5V
/ +1.5V / +1.8V / +2.5V
23, 24, 28, 29
15, 23, 24
15, 23, 24
Pin No.
7, 8, 22
BIT
23, 24
13, 25
25, 26
21
23
26
19
19
Voltage Measured
) / +3.3V
TT
) / V
BATT
0.00625
0.00625
0.00469
0.0625
0.0125
0.0172
0.0156
0.0094
0.0078
0.0065
1 LSB
Value
0.026
0.013
1.667 V
6.67 V
3.33 V
Scale
1.6 V
3.2 V
4.4 V
4.0 V
2.4 V
2.0 V
1.6 V
1.2 V
16 V
Full
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22
Example Calculations
code for each voltage (or vice versa) can be calculated.
Example:
channel, is calculated as follows:
where:
Given the LSB value for each channel, the corresponding
Similarly, the voltage, given the code in a particular
FSB_V
The code for 1.8 V in a 1.8 V channel is:
10 V is connected to the 12 V channel.
1 LSB = 0.0625.
Code = 160 decimal.
V
V
3GIO,
1.25V
CCP1
G
CCP2
0.9V
ICH,
1.5V
1.8V
2.5V
3.3V
12V
BIT
TT
5V
,
,
,
Figure 36. Voltage Input Structures
Code +
Code +
Voltage + Code
100kΩ
32kΩ
30kΩ
51kΩ
30kΩ
68kΩ
76kΩ
8kΩ
8kΩ
92kΩ
77kΩ
72kΩ
66kΩ
91kΩ
72kΩ
71kΩ
39kΩ
16kΩ
Voltage
0.0094
1 LSB
1.8
+ 192 (that is, 3 4 scale)
35pF
10pF
10pF
8pF
35pF
10pF
5pF
5pF
5pF
1 LSB
MUX