GX3146 Datasheet, PDF (7/46 Pages) Semtech Corporation – Crosspoint Switch with Trace Equalization and Output De-emphasis

Table 1-1: Ball Descriptions (Continued)
Ball #
Ball Name
I/O Description
Filtering
R17
R33
T17
T33
AH17
AH33
AJ17
AJ33
LDO2
LDO0
LF2
LF0
LF1
LF_DIGITAL
LDO1
LDO_DIGITAL
—
LDO filter capacitor for VCO_2. Connect through a 220nF capacitor to ground.
See Figure 3-3 for configuration.
—
LDO filter capacitor for VCO_0. Connect through a 220nF capacitor to ground.
See Figure 3-3 for configuration.
—
PLL loop filter capacitor for VCO_2. See Figure 3-3 for configuration. Leave NC
if not used.
—
PLL loop filter capacitor for VCO_0. See Figure 3-3 for configuration. Leave NC
if not used.
—
PLL loop filter capacitor for VCO_1. See Figure 3-3 for configuration. Leave NC
if not used.
—
PLL loop filter capacitor for VCO_DIGITAL. Connect through a 47nF capacitor
to ground. See Figure 3-3 for configuration.
—
LDO filter capacitor for VCO_1. Connect through a 220nF capacitor to ground.
See Figure 3-3 for configuration.
—
LDO filter capacitor for VCO_DIGITAL. Connect through a 220nF capacitor to
ground. See Figure 3-3 for configuration.
Crystal Oscillator
AE35
AF35
REF_CLK_IN
REF_CLK_OUT
—
Connect a 27MHz crystal between this ball and REF_CLK_OUT (or connect to a
27MHz clock source). See Section 4.9 and Figure 3-5.
—
Connect a 27MHz crystal between this ball and REF_CLK_IN (if a clock source is
used, leave floating). See Section 4.9 and Figure 3-5. Leave NC if not used.
External Clocks
R15
R35
T15
T35
AH15
AH35
AJ15
AJ35
BH45
EXT_CLK2
I
External CML clock for Pattern Generator 1 (true). Leave NC if not used.
EXT_CLK0
I
External CML clock for Pattern Checker 0 (true). Leave NC if not used.
EXT_CLK2
I
External CML clock for Pattern Generator 1 (complement). Leave NC if not
used.
EXT_CLK0
I
External CML clock for Pattern Checker 0 (complement). Leave NC if not used.
EXT_CLK1
I
External CML clock for Pattern Checker 1 (complement). Leave NC if not used.
EXT_CLK
_DIGITAL
I
External CML clock for Pattern Transmitter 0/Digital Core (complement). Leave
NC if not used.
EXT_CLK1
I
External CML clock for Pattern Checker 1 (true). Leave NC if not used.
EXT_CLK
_DIGITAL
I
External CML clock for Pattern Transmitter 0/Digital Core (true). Leave NC if
not used.
Clock select between external clock source (EXT_CLK_DIGITAL) and internal
DIGITAL_CL_SEL
I
VCO (VCO_DIGITAL). This pin has a weak internal pull-up, and should be pulled
LOW to use an external clock.
GX3146 146 x 146 3.5Gb/s Crosspoint
Final Data Sheet Rev. 2
GENDOC-056075 March 2013
www.semtech.com
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