QLX4600LIQT7 Intersil, QLX4600LIQT7 Datasheet - Page 11

• Manufacturer Part Number: QLX4600LIQT7
• Description: IC EQUALIZER REC 6.25GBPS 46QFN
• Manufacturer: Intersil
• Series: QLx™r

Specifications of QLX4600LIQT7

• Applications: Data Transport
• Voltage - Supply: 1.1 V ~ 1.3 V
• Package / Case: 46-WQFN
• Mounting Type: Surface Mount
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Other names: QLX4600LIQT7-TR

QLx4600-SL30
OPERATION
The QLx4600-SL30 is an advanced quad lane-extender for high-speed interconnects. A functional diagram of one of the four channels in the
QLx4600-SL30 is shown in Figure 7. In addition to a robust equalization filter to compensate for channel loss and restore signal fidelity, the
QLx4600-SL30 contains unique integrated features to preserve special signaling protocols typically broken by other equalizers. The signal
detect function is used to mute the channel output when the equalized signal falls below the level determined by the Detection Threshold (DT)
pin voltage. This function is intended to preserve periods of line silence (“quiescent state” in InfiniBand contexts). Furthermore, the output of
the signal detect / DT comparator is used as a loss of signal (LOS) indicator to indicate the absence of a received signal.
As illustrated in Figure 7, the core of each high-speed signal path in the QLx4600-SL30 is a sophisticated equalizer followed by a limiting
amplifier. The equalizer compensates for skin loss, dielectric loss, and impedance discontinuities in the transmission channel. Each equalizer
is followed by a limiting amplification stage that provides a clean output signal with full amplitude swing and fast rise-fall times for reliable
signal decoding in a subsequent receiver.
FIGURE 7: FUNCTIONAL DIAGRAM OF A SINGLE CHANNEL WITHIN THE QLx4600-SL30
INDIVIDUALLY ADJUSTABLE EQUALIZATION BOOST
Each channel in the QLx4600-SL30 features an independently settable equalizer for custom signal restoration. Each equalizer can be set to
one of 32 levels of compensation when the serial bus is used to program the boost level and one of 18 compensation levels when the CP[k]
pins are used to set the level. The equalizer transfer functions for a subset of these compensation levels are plotted in Figure 8. The flexibility
of this adjustable compensation architecture enables signal fidelity to be optimized on a channel-by-channel basis, providing support for a
wide variety of channel characteristics and data rates ranging from 2.5 to 6.25Gb/s. Because the boost level is externally set rather than
internally adapted, the QLx4600-SL30 provides reliable communication from the very first bit transmitted. There is no time needed for
adaptation and control loop convergence. Furthermore, there are no pathological data patterns that will cause the QLx4600-SL30 to move to
an incorrect boost level.
The Applications Information section beginning on page 14 details how to set the boost level by both the CP-pin voltage approach and the
serial programming approach.
FIGURE 8: EQUALIZER TRANSFER FUNCTIONS FOR SETTINGS 0, 5, 10, 15, 20, 25, AND 31 IN THE QLx4600-SL30
QLx4600-SL30 v3.0
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©2009 Quellan, Inc