JAJSFA9E November 2011 – April 2018 ADS5294
PRODUCTION DATA.
| ADDR. (HEX) | D15 | D14 | D13 | D12 | D11 | D10 | D9 | D8 | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 | NAME |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 42 | X | X | PHASE_DDR<1:0> | ||||||||||||||
| 46 | 1 | X | EN_SDR | ||||||||||||||
| 46 | 1 | X | FALL_SDR |
The output interface of the ADS5294 is normally a DDR interface, with the LCLK rising edge and falling edge transitions in the middle of alternate data windows. This default phase is shown in Figure 57.
Figure 57. Default Phase of LCLK
The phase of LCLK is programmed relative to the output frame clock and data using bits PHASE_DDR<1:0>. The LCLK phase modes are shown in Figure 58.
Figure 58. Phase Programmability Modes for LCLK
In addition to programming the phase of the LCLK in the DDR mode, the device also operates in SDR mode by setting bit EN_SDR to 1. In SDR mode, the bit clock (LCLK) is output at 14-times the input clock, or twice the rate as in DDR mode. Depending on the state of FALL_SDR, the LCLK may be output in either of the two manners shown in Figure 59. As can be seen in Figure 59, only the LCLK rising (or falling edge) is used to capture the output data in SDR mode. The SDR mode does not work well beyond 40 MSPS because the LCLK frequency will become very high.
Figure 59. SDR Interface Modes