Gas line image

AT84AD001B, AT84AD004 dual 8-bit ADCs interleaving mode

Post Date:
07/16/07
Question:
What are the recommended settings for the AT84AD001B, AT84AD004 dual 8-bit ADCs in interleaving mode?
Answer:
The recommended settings for the ADCs in interleaving mode are the following:
1. Clock I --> ADC I and Clock IN --> ADC Q.
2. Input I --> ADC I and Input I --> ADC Q.
3. ISA should be set to -50 ps.
4. FiSDA should be set to a proper value depending on the input frequency (usually the range is between -30 to -10 ps).
5. The DMUX can be set to 1:2 mode but then you will have to be careful on the signal reconstruction process.
6. The output clock can be set to Fs/2 or Fs/4 (i.e. single or double data rate) at your convenience.
7. The duty cycle should be 50% otherwise you will have some jitter and noise.
This gives for the 3WSI:
address 000: data 0111 1100 0010 1100
(Fs/4, start a calibration, DMUX 1:2, Binary)
or
address 000: 0111 0100 0010 1000
(Fs/4, keep last calibration, DMUX 1:2, gray)
adress 100: 1000 0100 00 011 011 to set the ISA to -50 ps on the I and Q channels.