Datasheet

D
OUT
-
D
OUT
+
D
R
IN
-
R
IN
+
R
DIN/
ROUT
PCLK
TRFB/RRFB: 0 TRFB/RRFB: 1
DS92LX1621, DS92LX1622
www.ti.com SNLS327I –MAY 2010–REVISED JANUARY 2014
SIGNAL QUALITY ENHANCERS
Des - Receiver Input Equalization (EQ)
The receiver inputs provided input equalization filter in order to compensate for loss from the media. The level of
equalization is controlled via register setting.
EMI REDUCTION
Des - Receiver Staggered Output
The Receiver staggered outputs allows for outputs to switch in a random distribution of transitions within a
defined window. Outputs transitions are distributed randomly. This minimizes the number of outputs switching
simultaneously and helps to reduce supply noise. In addition it spreads the noise spectrum out reducing overall
EMI.
Des Spread Spectrum Clocking Compatibilty
The DS92LX1622 parallel data and clock outputs have programmable SSCG ranges from 9 kHz–66 kHz and
±0.5%– ±2% from 20 MHz to 50 MHz. The modulation rate and modulation frequency variation of output spread
is controlled through the SSC control registers.
PIXEL CLOCK EDGE SELECT (TRFB/RRFB)
The TRFB/RRFB selects which edge of the Pixel Clock is used. For the SER, this register determines the edge
that the data is latched on. If TRFB register is 1, data is latched on the Rising edge of the PCLK. If TRFB register
is 0, data is latched on the Falling edge of the PCLK. For the DES, this register determines the edge that the
data is strobed on. If RRFB register is 1, data is strobed on the Rising edge of the PCLK. If RRFB register is 0,
data is strobed on the Falling edge of the PCLK.
Figure 37. Programmable PCLK Strobe Select
Applications Information
AC COUPLING
The SER/DES supports only AC-coupled interconnects through an integrated DC balanced decoding scheme. To
use the device in an AC-coupled application, insert external AC coupling capacitors in series in the Channel Link
III signal path as illustrated in Figure 38.
Figure 38. AC-Coupled Application
For high-speed Channel Link III transmissions, the smallest available package should be used for the AC
coupling capacitor. This will help minimize degradation of signal quality due to package parasitics. The most
common used capacitor value for the interface is 0.1μF.
TYPICAL APPLICATION CONNECTION
Figure 39 shows a typical connection of the DS92LX1621 Serializer.
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