
ADC_DCLK
ADC_DATA
Ch A
Ch B
th
tsu
th
tsu
t
/6
CLK
ADC_DCLK
ADC_DATA
Ch A
Ch B
th
tsu
th
tsu
t
/3
CLK
SLOS711B – NOVEMBER 2011 – REVISED MARCH 2012
10.7 SERIAL LVDS ADC RX INTERFACE
Note: Set MASTER_OVERRIDE_RX bit to ‘1’ before entering RX LVDS interface.
The 12-bit ADC output data is serialized onto one or two LVDS pairs per ADC. ADCA and ADCB data
outputs can be quadrature data or two independent receive channels. Two serialization modes are
available.
1-Wire mode: 1 LVDS pair for the data from each ADC. It will operate in a DDR fashion serialized to a
frequency of 6x the pattern word rate. A frame clock (ADC_FCLKOUT) at the word rate and a bit clock
(ADC_DCLKOUT) at 6x. Example: 50MSPS 12-bit pattern will serialize to 300MHz on each LVDS pair,
frame clock of 50MHz and bit clock of 300MHz. Effective serial data rate is 600Mbps due to bit
transitions on rising and falling edge of bit clock.
A.
tCLK = Time period of ADC output frame clock.
B.
th is minimum hold time required at the AFE722x output.
C.
tsu is minimum setup time required at the AFE722x output.
Figure 10-9. RX 1-Wire Mode Timing Diagram
2-Wire mode, DDR clock: 2 LVDS pairs for the data from each ADC. It will operate in a DDR fashion
serialized to a frequency of 3x the pattern word rate. A frame clock (ADC_FCLKOUT) at half the word
rate and a bit clock (ADC_DCLKOUT) at 3x. Example: 50MSPS 12-bit pattern will serialize to 150MHz
on each LVDS pair, frame clock of 25MHz and bit clock of 150MHz. Effective serial data rate is
300Mbps on each LVDS pair due to bit transitions on rising and falling edge of bit clock.
A.
tCLK = Time period of ADC output frame clock.
B.
th is minimum hold time required at the AFE722x output.
C.
tsu is minimum setup time required at the AFE722x output.
Figure 10-10. RX 2-Wire Mode, DDR Clock Timing Diagram
2-Wire mode, SDR clock: 2 LVDS pairs for the data from each ADC. It will operate in a SDR fashion
serialized to a frequency of 6x the pattern word rate. A frame clock (ADC_FCLKOUT) at the word rate
and a bit clock (ADC_DCLKOUT) at 6x. Example: 50MSPS 12-bit pattern will serialize to 300MHz on
each LVDS pair, frame clock of 50MHz and bit clock of 300MHz. Effective serial data rate is 300Mbps
on each LVDS pair due to bit transitions on rising edge of bit clock.
86
DIGITAL INTERFACE
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