DAC8550_16 Datasheet, PDF (21/31 Pages) Texas Instruments – 16-bit, Ultra-Low Glitch, Voltage Output Digital-To-Analog Converter

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Typical Applications (continued)
0.1
0.05
0
-0.05
-0.1
0
10k 20k 30k 40k 50k 60k 65535
Code
D001
Figure 53. Total Unadjusted Error
8.2.2 Using REF02 as a Power Supply for DAC8550
+15V
DAC8550
SLAS476F – MARCH 2006 – REVISED MARCH 2016
10
8
6
4
2
0
-2
-4
-6
-8
-10
0
10k 20k 30k 40k 50k 60k 65535
Code
D002
Figure 54. Integral Nonlineareity
+5V
REF02
285mA
Three-Wire
Serial
Interface
SYNC
SCLK
D_IN
DAC8550
V_OUT = 0V to 5V
Figure 55. REF02 as a Power Supply to the DAC8550
8.2.2.1 Design Requirements
Due to the extremely low supply current required by the DAC8550, an alternative option is to use a REF02 to
supply the required voltage to the device, as shown in Figure 55. See +5V Precision Voltage Reference
(SBVS003) for more information.
8.2.2.2 Detailed Design Procedure
This configuration is especially useful if the power supply is quite noisy or if the system supply voltages are at
some value other than 5 V. The REF02 outputs a steady supply voltage for the DAC8550. If the REF02 is used,
the current it needs to supply to the DAC8550 is 250 μA. This configuration is with no load on the output of the
DAC. When a DAC output is loaded, the REF02 also needs to supply the current to the load. The total typical
current required (with a 5-kΩ load on the DAC output) is calculated with Equation 5.
200 µA + ^{5 V} = 1.2 mA
5 kW
(5)
The load regulation of the REF02 is typically 0.005%/mA, resulting in an error of 299 μV for the 1.2-mA current
drawn from it. This value corresponds to an 8.9-LSB error.
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