DAC8408FPCZ Analog Devices Inc, DAC8408FPCZ Datasheet - Page 14

• Manufacturer Part Number: DAC8408FPCZ
• Description: PLCC-28 MARKED AS "DAC840
• Manufacturer: Analog Devices Inc

Specifications of DAC8408FPCZ

• Rohs Compliant: YES
• Settling Time: 190ns
• Number Of Bits: 8
• Data Interface: Parallel
• Number Of Converters: 4
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-LCC (J-Lead)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DAC8408
A LOW-DISTORTION, PROGRAMMABLE
SINEWAVE OSCILLATOR
By varying the previous state-variable filter topology slightly,
one can obtain a very low distortion sinewave oscillator with
programmable frequency feature as shown in Figure 11. Again,
DAC B and DAC D in tandem control the oscillating frequency
based on the relationship f
accomplished via the 82.5 k and the 20 k potentiometer.
The Q of the oscillator is determined by the ratio of 10 k and
Figure 11. A Digitally Programmable, Low-Distortion Sinewave Oscillator
C
= 1/2 RC. Positive feedback is
–14–
475 in series with the FET transistor, which acts as an auto-
matic gain control variable resistor. The AGC action maintains
a very stable sinewave amplitude at any frequency. Again, only
two ICs accomplish a very useful function.
At the highest frequency setting, the harmonic distortion level
measures 0.016%. As the frequencies drop, distortion also drops
to a low of 0.006%. At the lowest frequency setting, distortion
came back up to a worst case of 0.035%.
REV. A