GS6152 Datasheet, PDF (16/80 Pages) Semtech Corporation – Multi-Rate 6G UHD-SDI

4. Detailed Description
The GS6152 is a multi-standard CDR for signals operating at the following data rates:
125Mb/s, 270Mb/s, 1.485Gb/s, 1.485/1.001Gb/s, 2.97Gb/s, 2.97/1.001Gb/s, 5.94Gb/s,
and 5.94/1.001Gb/s.
4.1 Serial Data Inputs
The GS6152 features four 100Ω terminated differential input buffers.
A serial data input signal may be connected to any of the following input pin pairs of the
device: DDI0/DDI0, DDI1/DDI1, DDI2/DDI2, and DDI3/DDI3.
By default, the self-biasing circuit at the input is enabled to allow AC coupling to
upstream devices. To enable DC coupling of the inputs, the user must disable the
self-biasing network by setting bits 4:4 through 7:7 to 0 in the register 7_h:
DDI[0:3]_TRACE_EQ_DC_TERM_ENABLE.
In order to select DC coupling, please ensure that the output common mode of the
upstream device is in range of the input common mode voltage range shown in
Table 2-2.
The serial digital input buffer is capable of operating with any binary coded signal that
meets the input signal level requirements defined below, with any data rate between
3Mb/s and 5.94Gb/s.
4.1.1 Input Trace Equalization
The GS6152 features adjustable trace equalization to compensate for PCB trace
dielectric losses up to half the maximum supported data rate, or 3GHz.
Table 4-1: Equalization Settings
Data Rate
2.97Gb/s and below
5.94Gb/s
2.97Gb/s and below
—
Trace Loss
0-7dB of trace loss at 1.5GHz
0-10dB of trace loss at 3GHz
7-12dB of trace loss at 1.5GHz
negligible trace loss
Settings
LOW (default)
HIGH
0dB or EQ_BYPASS
These settings are selected using the DDI0_TRACE_EQ_CONTROL,
DDI1_TRACE_EQ_CONTROL, DDI2_TRACE_EQ_CONTROL and
DDI3_TRACE_EQ_CONTROL bits in the INPUT_CONTROL_REG_0 register at address 5_h.
The default state of the device is input trace equalization on all inputs set to LOW.
If system jitter profile allows, it is recommended that the loop bandwidth is reduced to
the minimum setting to maximize performance.
GS6152
Final Data Sheet
PDS-060984
Rev.2
July 2015
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