ZHCSEE2B December 2015 – January 2023 ADS54J66
PRODUCTION DATA
The ADS54J66 supports decimation-by-2 and -4 and un-decimated output. The four channels can be configured as pairs (A, B and C, D; however, the same decimation factor must be chosen for all four channels).
Figure 7-2 shows signal processing done in the digital down-conversion (DDC) block of the ADS54J66. Table 7-1 shows available modes of operation for this block.
Figure 7-2 Digital Down-Conversion Block Diagram| OPERATING MODE | DESCRIPTION | DIGITAL MIXER | DECIMATION | BANDWIDTH | OUTPUT FORMAT | MAX OUTPUT RATE | |
|---|---|---|---|---|---|---|---|
| 491 MSPS | 368 MSPS | ||||||
| 0 | Decimation | ±fS / 4 | 2 | 200 MHz | 150 MHz | Complex | 250 MSPS |
| 2 | – | 2 | 100 MHz | 75 MHz | Real | 250 MSPS | |
| 4 | N × fS / 16 | 2 | 100 MHz | 75 MHz | Real | 250 MSPS | |
| 5 | N × fS / 16 | 2 | 200 MHz | 150 MHz | Complex | 250 MSPS | |
| 6 | N × fS / 16 | 4 | 100 MHz | 75 MHz | Complex | 125 MSPS | |
| 7 | N × fS / 16 | 2 | 100 MHz | 75 MHz | Real | 500 MSPS | |
| 8 | No decimation | – | – | 245.76 MHz | 184.32 MHz | Real | 500 MSPS |
Table 7-2 shows characteristics of different blocks of DDC signal processing blocks active in different modes.
| MODE | fmix1 | FILTER AND DECIMATION | fmix2 | OUTPUT |
|---|---|---|---|---|
| 0 | fS / 4 | LPF cutoff at fS / 4, decimation-by-2 | Not used | I, Q data at 250 MSPS each are given out |
| 2 | Not used | LPF or HPF cutoff at fS / 4, decimation-by-2 | Not used | Straight 250 MSPS data are given out |
| 4 | k fS / 16 | LPF cutoff at fS / 8, decimation-by-2 | fS / 8 | Real data at 250 MSPS are given out |
| 5 | k fS / 16 | LPF cutoff at fS / 8, decimation-by-2 | Not used | I, Q data at 250 MSPS each are given out |
| 6 | k fS / 16 | LPF cutoff at fS / 8, decimation-by-4 | Not used | I, Q data at 125 MSPS each are given out |
| 7 | k fS / 16 | LPF cutoff at fS8, decimation-by-2 | fS / 8 | Real data are up-scaled, zero-padded and given out at 500 MSPS |
| Default | Not used | Not used | Not used | Straight 500-MSPS, 14-bit data are given out |