MAX9254 Maxim, MAX9254 Datasheet - Page 15

• Manufacturer Part Number: MAX9254
• Description: The MAX9242/MAX9244/MAX9246/MAX9254 deserialize three LVDS serial-data inputs into 21 single-ended LVCMOS/LVTTL outputs
• Manufacturer: Maxim

Figure 14. Output Waveforms when Spread is Added
Figure 15. Output Waveforms when Spread is Removed
spread-spectrum PLL locks immediately after (see
Figure 16). If the spread-spectrum PLL loses lock, it
locks again with only one PLL lock delay (see Figure 17).
Bit errors experienced with DC-coupling (Figure 18)
can be eliminated by increasing the receiver common-
mode voltage range through AC-coupling. AC-coupling
Figure 13. Output Waveforms when Spread Amount is Changed
RxCLKOUT
RxCLKOUT
RxCLKOUT
RxOUT_
RxOUT_
RxOUT_
SSG
SSG
SSG
______________________________________________________________________________________
±4% OR ±2% SPREAD
±4% OR ±2% SPREAD
21-Bit Deserializers with Programmable
NO SPREAD
AC-Coupling Benefits
Spread Spectrum and DC Balance
DATA SWITCHING BUT NOT VALID
RPLLS2 (32,800 x RCIP)
RPLLS2 (32,800 x RCIP)
RPLLS2 (32,800 x RCIP)
±2% OR ±4% SPREAD
±2% OR ±4% SPREAD
NO SPREAD
LOW
LOW
increases the common-mode voltage range of an LVDS
receiver to nearly the voltage rating of the capacitor. The
typical LVDS driver output is 350mV centered on a 1.25V
offset voltage, making single-ended output voltages of
1.425V and 1.075V. An LVDS receiver accepts signals
from 0V to 2.4V, allowing approximately ±1V common-
mode difference between the driver and receiver on a
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