DAC80 Burr-Brown Corporation, DAC80 Datasheet - Page 6

• Manufacturer Part Number: DAC80
• Description: Monolithic 12-Bit DIGITAL-TO-ANALOG CONVERTERS
• Manufacturer: Burr-Brown Corporation

FIGURE 2. Power Supply Rejection vs Power Supply Ripple.
(pin 16) for specified operation. This reference may be used
externally also, but external current drain is limited to
2.5mA.
If a varying load is to be driven, an external buffer amplifier
is recommended to drive the load in order to isolate bipolar
offset from load variations. Gain and bipolar offset adjust-
ments should be made under constant load conditions.
LOGIC INPUT COMPATIBILITY
DAC80 digital inputs are TTL, LSTTL and 4000B,
54/74HC CMOS compatible. The input switching threshold
remains at the TTL threshold over the entire supply range.
Logic “0” input current over temperature is low enough to
permit driving DAC80 directly from outputs of 4000B and
54/74C CMOS devices.
FIGURE 3. Power Supply and External Adjustment Connection Diagrams.
10
11
12
1
2
3
4
5
6
7
8
9
0.0001
0.001
0.01
0.1
Switches
Resistor
Network
Current
Ladder
1
12-Bit
and
Voltage Output Models
®
DAC80/80P
10
Power Supply Ripple Frequency (Hz)
Reference
Control
Circuit
100
6.3k
5k
5k
24
23
22
21
20
19
18
17
16
15
14
13
1k
–V
CC
0.01µF
3.9M
10k
10M
+V
1µF
1µF
CC
100k
10k
10k
100k
100k
+V
–V
+V
–V
to
to
CC
CC
CC
CC
6
10
11
12
1
2
3
4
5
6
7
8
9
OPERATING INSTRUCTIONS
POWER SUPPLY CONNECTIONS
Connect power supply voltages as shown in Figure 3. For
optimum performance and noise rejection, power supply
decoupling capacitors should be added as shown. These
capacitors (1 F tantalum) should be located close to the
DAC80.
All DAC80 models can operate over the entire power supply
range of 11.4V to 16.5V. Even with supply levels drop-
ping to 11.4V, the DAC80 can swing a full 10V range,
provided the load current is limited to 2.5mA. With power
supplies greater than 12V, the DAC80 output can be loaded
up to 5mA. For output swing of 5V or less, the output
current is 5mA, minimum, over the entire V
No bleed resistor is needed from +V
needed with prior hybrid Z versions of DAC80. Existing
DAC80 must omit the resistor to pin 24 to insure proper
operation.
EXTERNAL OFFSET AND GAIN ADJUSTMENT
Offset and gain may be trimmed by installing external Offset
and Gain potentiometers. Connect these potentiometers as
shown in Figure 3 and adjust as described below. TCR of the
potentiometers should be 100ppm/ C or less. The 3.9M
and 10M
cated close to the DAC80 to prevent noise pickup. If it is not
convenient to use these high value resistors, an equivalent
“T” network, as shown in Figure 4, may be substituted.
12V OPERATION
12V applications that are being converted to the monolithic
Switches
Resistor
Network
Current
Ladder
12-Bit
and
Current Output Models
resistors (20% carbon or better) should be lo-
Reference
Control
Circuit
3k
5k
6.3k
2k
24
23
22
21
20
19
18
17
16
15
14
13
CC
3.9M
0.01µF
to pin 24, as was
10M
CC
1µF
1µF
range.
10k
10k
100k
100k
+V
+V
–V
–V
to
to
CC
CC
CC
CC