DAC7631EB1K BURR-BROWN [Burr-Brown Corporation], DAC7631EB1K Datasheet - Page 12

• Manufacturer Part Number: DAC7631EB1K
• Description: Serial Input, 16-Bit, Voltage Output DIGITAL-TO-ANALOG CONVERTER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

FIGURE 2. Basic Single-Supply Operation.
FIGURE 3. Basic Dual-Supply Operation.
ANALOG OUTPUTS
When V
fier can swing to within 2.25V of the supply rails, guaran-
teed over the –40 C to +85 C temperature range. When
V
connected to ground, the output can swing to ground. Care
must also be taken when measuring the zero-scale error
when V
below ground, the output voltage may not change for the
first few digital input codes (0000
the output amplifier has a negative offset. At the negative
limit of –2mV, the first specified output starts at code 0040
Due to the high accuracy of these D/A converters, system
design problems such as grounding and contact resistance
become very important. A 16-bit converter with a 2.5V full-
scale range has a 1LSB value of 38 V. With a load current
of 1mA, series wiring and connector resistance of only
40m (R
Figure 4. To understand what this means in terms of a
system layout, the resistivity of a typical 1 ounce copper-
clad printed circuit board is 1/2 m
SS
= 0V (single-supply operation), and with R
SS
SS
W2
= –5V (dual supply operation), the output ampli-
= 0V. Since the output voltage cannot swing
) will cause a voltage drop of 40 V, as shown in
®
+5V
DAC7631
0.1 F
Serial Data Out
Serial Data In
Chip Select
+
Serial Data Out
+2.5000V
1 F
Serial Data In
Clock
Chip Select
+2.5000V
–2.5000V
H
Clock
, 0001
per square. For a 1mA
H
, 0002
10
1
2
3
4
5
6
7
8
9
V
V
V
V
DGND
V
SDO
SDI
CLK
CS
REF
REF
REF
REF
DD
LOAD
H
10
1
2
3
4
5
6
7
8
9
, etc.) if
H
H Sense
L
L Sense
V
V
V
V
DGND
V
SDO
SDI
CLK
CS
REF
REF
REF
REF
DD
also
H
H Sense
L
L Sense
DAC7631
H
.
12
DAC7631
V
load, a 10 milli-inch wide printed circuit conductor 600
milli-inches long will result in a voltage drop of 30 V.
The DAC7631 offers a force and sense output configuration
for the high open-loop gain output amplifier. This feature
allows the loop around the output amplifier to be closed at
the load (as shown in Figure 4), thus ensuring an accurate
output voltage.
REFERENCE INPUTS
The reference inputs, V
between V
is at least 1.25V greater than V
each DAC is equal to V
(essentially, the offset of the output op amp). The maximum
output is equal to V
that V
connected to ground or must be in the range of –4.75V to
–5.25V. The voltage on V
the converter. If V
tions, the bias values may be in error and proper operation
of the device is not guaranteed.
OUT
RSTSEL
AGND
Sense
LOAD
LDAC
V
RST
V
V
V
OUT
NC
OUT
CC
SS
SS
RSTSEL
AGND
Sense
LOAD
20
19
18
17
16
15
14
13
12
LDAC
11
V
RST
(the negative power supply) must either be
SS
V
V
OUT
NC
CC
SS
+ 2.5V and V
20
19
18
17
16
15
14
13
12
11
SS
0V to +2.5V
REF
Reset DAC Registers
Load
Load DAC Registers
is not in one of these two configura-
0.1 F
H plus a similar offset voltage. Note
REF
REF
–2.5V to +2.5V
L and V
SS
0.1 F
0.1 F
Reset DAC Registers
Load
Load DAC Registers
CC
L plus a small offset voltage
sets several bias points within
+
REF
– 2.5V, provided that V
1 F
+5V
L. The minimum output of
+
+
REF
1 F
1 F
–5V
H, can be any voltage
+5V
REF
H