EP4SE360F35I4 Datasheet, PDF (294/432 Pages) Altera Corporation – This section provides a complete overview of all features relating to the Stratix IV device family, which is the most architecturlly advanced

8–14
Chapter 8: High-Speed Differential I/O Interfaces and DPA in Stratix IV Devices
Differential Transmitter
Programmable V_OD and Programmable Pre-Emphasis
Stratix IV LVDS transmitters support programmable pre-emphasis and
programmable V_OD. Pre-emphasis increases the amplitude of the high-frequency
component of the output signal, and thus helps to compensate for the
frequency-dependent attenuation along the transmission line. Figure 8–8 shows the
differential LVDS output.
Figure 8–8. Differential V_OD
Single-Ended Waveform
V_CM
V_OD
Positive Channel (p)
Negative Channel (n)
Ground
Differential Waveform
V_OD
V_OD (diff peak - peak) = 2 x V_OD(single-ended)
p - n = 0V
V_OD
Figure 8–9 shows the LVDS output with pre-emphasis.
Figure 8–9. Programmable Pre-Emphasis ⁽¹⁾
OUT
OUT
V_P
V_OD
V_P
Note to Figure 8–9:
(1) V_P— voltage boost from pre-emphasis. V_OD— Differential output voltage (peak-peak).
Stratix IV Device Handbook
Volume 1
September 2012 Altera Corporation