AD9501 Analog Devices, AD9501 Datasheet - Page 10

• Manufacturer Part Number: AD9501
• Description: Digitally Programmable Delay Generator
• Manufacturer: Analog Devices

AD9501
AD9501 #1 should be programmed so its delay is greater than
the zero-set programmed delay of AD9501 #2. To accomplish
this, continue to apply clock pulses and increment the digital
data into AD9501 #1 until the output of the successive approxi-
mation register (SAR) is 02H (00000010) or greater. At this
point, the delay through AD9501 #1 is slightly longer than the
delay through AD9501 #2, making it possible to use the SAR
Figure 7. Programmable Pulse Delay Generator
Figure 8. Digital Delay Detector
–10–
output as the zero reference point for measuring the unknown
delay when it is reinserted into the circuit.
This calibration procedure compensates for the setup time of
the flip-flop, stray circuit delays and other nonideal characteristics
which are an inherent part of any circuit.
Eight cycles of the clock input are required to determine the
value of the unknown delay.
REV. A