DAC702 BURR-BROWN [Burr-Brown Corporation], DAC702 Datasheet - Page 7

• Manufacturer Part Number: DAC702
• Description: Monolithic 16-Bit DIGITAL-TO-ANALOG CONVERTERS
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

POWER SUPPLY SENSITIVITY
Power supply sensitivity is a measure of the effect of a
change in a power supply voltage on the D/A converter
output. It is defined as a percent of FSR change in the output
per percent of change in either the positive supply (+V
negative supply (–V
nominal power supply voltages (see Figure 2).
It is specified for DC or low frequency changes. The typical
performance curve in Figure 2 shows the effect of high
frequency changes in power supply voltages.
FIGURE 2. Power Supply Rejection vs Power Supply Ripple
REFERENCE SUPPLY
All models have an internal low-noise +6.3V reference
voltage derived from an on-chip buried zener diode. This
reference voltage, available to the user, has a tolerance of
1.5mA is available for external loads. Since the output
impedance of the reference output is typically 1W, the
external load should remain constant.
If a varying load is to be driven by the reference supply, an
external buffer amplifier is recommended to drive the load
in order to isolate the bipolar offset (connected internally to
the reference) from load variations.
OPERATING INSTRUCTIONS
POWER SUPPLY CONNECTIONS
For optimum performance and noise rejection, power sup-
ply decoupling capacitors should be added as shown in the
Connection Diagram. 1 F tantalum capacitors should be
located close to the D/A converter.
EXTERNAL ZERO AND GAIN ADJUSTMENT
Zero and gain may be trimmed by installing external zero
and gain potentiometers. Connect these potentiometers as
shown in the Connection Diagram and adjust as described
below. TCR of the potentiometers should be 100ppm/ C or
5% (KH models) and 1% (BH models). A minimum of
0.030
0.025
0.020
0.015
0.005
0.01
0
1
Frequency.
10
Power Supply Ripple Frequency (Hz)
CC
) or logic supply (V
100
1k
–15V Supply
Supply
+5V
DD
10k
) about the
Supply
+15V
100k
CC
),
7
less. The 3.9M
better) should be located close to the D/A converter to
prevent noise pickup. If it is not convenient to use these
high-value resistors, an equivalent “T” network, as shown in
Figure 3, may be substituted in place of the 3.9M part. A
0.001 F to 0.01 F ceramic capacitor should be connected
from Gain Adjust to Common to prevent noise pickup. Refer
to Figures 4 and 5 for the relationship of zero and gain
adjustments to unipolar and bipolar D/A converters.
FIGURE 3. Equivalent Resistances.
FIGURE 4. Relationship of Zero and Gain Adjustments for
FIGURE 5. Relationship of Zero and Gain Adjustments for
Zero Adjust
Zero Adjust
Translates
Range of
the Line
3.9M
+ Full
Scale
1LSB
Input =
FFFF
Unipolar D/A Converters, DAC701.
Bipolar D/A Converters, DAC702 and DAC703.
+ Full
Scale
– Full
Scale
H
DAC701, 702, 703
and 270k
Input =
FFFF
Digital Input
H
1LSB
MSB on All
Others Off 7FFF
180k
Digital Input
resistors ( 20% carbon or
Gain Adjust
the Line
Rotates
the Line
Rotates
Input =
0000
Adjust
H
Gain
10k
H
Offset
Adjust
Translates
the Line
180k
Range
of Gain
Adjust
Range
and
Offset
Adjust
Input =
0000
of Gain
Range
Adjust
H
®