EVAL-AD5680EB AD [Analog Devices], EVAL-AD5680EB Datasheet - Page 14

• Manufacturer Part Number: EVAL-AD5680EB
• Description: 5 V 18-Bit nanoDAC in a SOT-23
• Manufacturer: AD [Analog Devices]

AD5680
APPLICATIONS
CLOSED-LOOP APPLICATIONS
The AD5680 is suitable for closed-loop low bandwidth
applications. Ideally, the system bandwidth acts as a filter on the
DAC output. (See the Filter section for details of the DAC
output prefiltering and postfiltering.) The DAC updates at the
interpolation frequency of 10 kHz.
FILTER
The DAC output voltage for code transition 4092 to 4094 can be
seen in Figure 32. This is the DAC output unfiltered. Code 4092
does not have any interpolation but code 4094 has interpolation
with a 50% duty cycle. See Table 5. Figure 33 shows the DAC
output with a 50 Hz passive RC filter and Figure 34 shows the
output with a 300 Hz passive RC filter. An RC combination of
320 kΩ and 10 nF has been used to achieve the 50 Hz cutoff
frequency, and an RC combination of 81 kΩ and 10 nF has
been used to achieve the 300 Hz cutoff frequency.
CONTROLLER
1
CH1
20.0µV
Figure 31. Typical Closed-Loop Application
CODE 4092
Figure 32. DAC Output Unfiltered
DAC
ADC
M 500µs
CODE 4094
CH4
PLANT
0V
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2
2
1
1
CH1
CH1
Figure 34. DAC Output with 300 Hz Filter on Output
Figure 33. DAC Output with 50 Hz Filter on Output
20.0µV CH2 5V
20.0µV CH2 5V
CODE 4092
CODE 4092
M 500µs
M 500µs
CODE 4094
CODE 4094
CH2
CH2
Δ: 2.09ms
@: 1.28ms
Δ: 2.09ms
@: 1.28ms
1.4V
1.4V