DAC729JH BURR-BROWN [Burr-Brown Corporation], DAC729JH Datasheet - Page 9

• Manufacturer Part Number: DAC729JH
• Description: Ultra-High Resolution 18-BIT DIGITAL-TO-ANALOG CONVERTER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

FIGURE 7. V
FIGURE 8. Effect of V
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
6
7
8
9
Input = 3FFFF
DAC729.
REF
Adjust.
H
Ref. Adj.
Ref. Out
Ref. In
Digital Input
REF
MSB On,
All Others Off 2FFFF
– Full Scale
Gain Adjust
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
Adjust on a COB Connected
+ Full Scale
Rotates
the Line
1M
R
S
Adjustment Range
20k
Gives 20mV
R
S
00000
Ground Connection
= 1M
H
Holy Point
H
Range of
Gain Adjust
Offset Adjust
Translates
the Line
9
With the DAC connected for 0 to 10V output (Figure 13),
the adjustment procedure is to set the DAC code and mea-
sure as follows:
FOURTH MSB ADJUSTMENT (Pin 36)
1. Set Code = 11 1100 0000 0000 0000
2. Measure V
3. Set Code = 11 1011 1111 1111 1111
4. Measure V
5. Adjust 4th MSB potentiometer to make difference +38 V.
6. Repeat steps 1 through 5 to confirm.
THIRD MSB ADJUSTMENT (Pin 37)
1. Set Code = 11 1000 0000 0000 0000
2. Measure V
3. Set Code = 11 0111 1111 1111 1111
4. Measure V
5. Adjust 3rd MSB potentiometer to make difference +38 V.
6. Repeat steps 1 through 5 to confirm.
FIGURE 9. Typical Hook-Up Diagram with “Holy Point”
+5V V
+
DD
Digital Common
1µF
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
6
7
8
9
Ground and Kelvin Sense Load, Using Internal
Op Amp and Reference.
OUT
OUT
OUT
OUT
18-Bit
DAC
and record the difference.
and record the difference.
Ref. Out
Ref. In
DAC729
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
Common
I
Analog
OUT
+
1µF
–15V
Common
R
+
+15V
1µF
L