JAJSDZ9 October 2017 ADS54J64
PRODUCTION DATA.
Figure 49 shows the various operational modes available in the ADS54J64. In quad mode, the maximum output rate is half the sampling rate. The 2x interleaved data are filtered using a half-band filter (HBF) that can be configured as a low-pass or high-pass filter using register writes. In dual mode, the device can be operated at a full sampling rate with 2x interleaving and averaging of two channels.
Quad mode supports a maximum complex and a real bandwidth of 200 MHz. The HBF output can be brought directly on the JESD lines at half rate. The complex data are obtained through a digital down-converter (DDC) that is comprised of a 16-bit numerically controlled oscillator (NCO) and a 100-MHz or 200-MHz filter. The DDC also has a real output mode where the data are decimated by 2 and mixed to fOUT / 4 to support a bandwidth of 100 MHz. In addition to the DDC modes, the HBF output can be decimated by 2 to obtain an overall decimation by 4 on the 2x interleaved data.
Dual mode supports a maximum sampling rate of 1 GSPS. The 2x interleaved data from channel A and channel B (and likewise channels C and D) can be averaged and given on the JESD lanes.
Table 1 lists all modes of operation with the maximum bandwidth provided at a sample rate of 491.52 MSPS and 368.64 MSPS.
OPERATING MODE | DESCRIPTION | 1ST-STAGE DECIMATION | DIGITAL MIXER | 2ND-STAGE DECIMATION | BANDWIDTH AT 491.52 MSPS | BANDWIDTH AT 368.64 MSPS | OUTPUT MIXER | OUTPUT FORMAT | MAX OUTPUT RATE |
---|---|---|---|---|---|---|---|---|---|
0 | Decimation | 2 | ±fS / 4 | 2 | 200 MHz | 150 MHz | — | Complex | 250 MSPS |
1 | 2 | 16-bit NCO | 2 | 200 MHz | 150 MHz | — | Complex | 250 MSPS | |
2 | 2 | — | 2 | 100 MHz (LP, LP or HP, HP), 75 MHz (HP, LP or LP, HP) |
75 MHz, 56.25 MHz |
— | Real | 250 MSPS | |
3 | 2 | 16-bit NCO | Bypass | 200 MHz | 150 MHz | fOUT / 4 | Real | 500 MSPS | |
4 | 2 | 16-bit NCO | 2 | 100 MHz | 75 MHz | fOUT / 4 | Real | 250 MSPS | |
5 | Reserved | Reserved | Reserved | Reserved | Reserved | Reserved | Reserved | Reserved | |
6 | 2 | 16-bit NCO | 4 | 100 MHz | 75 MHz | — | Complex | 125 MSPS | |
7 | 2 | 16-bit NCO | 2 | 100 MHz | 75 MHz | fOUT / 4 | Real with zero insertion | 500 MSPS | |
8 | DDC bypass mode | 2 | — | — | 223 MHz | 167 MHz | — | Real | 500 MSPS |
8 | Dual ADC mode | — | — | — | — | — | — | — | 1000 MSPS |