GX4002 Datasheet, PDF (53/74 Pages) Gennum Corporation – Dynamic on-chip power management control

4. Typical Application Circuit
Ch1 Output
Ch0 Input
DIG_3V3
4.7kΩ
From SFP+
connector
or to/from
controller
4.7kΩ
Populate for
open-collector
mode
DIG_3V3
SDO0_3V3
Ch0_3V3
Ch1_3V3
From SFP+
connector
or to/from
controller
RESET ¹⁶ _RESET
1 13 17
100nF
6Ω
1kΩ
100nF
10Ω
AC Common Mode
Enhancement
Place close to chip
SDO1
15
SDO1
1kΩ ^{100Ω differential pair}
SDO1
14
SDO1
100nF
Ch1LF
1µF
Ch1VCOFILT
9 _Ch1LF
11
Ch1VCOFILT
Ch1LOS ^{8 Ch1LOS}
Ch0FAULT ^{32 Ch0FAULT}
6 SDI1
SDI1
100nF
100Ω differential pair
7
SDI1
SDI1
100nF
100nF
100nF
100nF
Place close to chip _1µF
SDI0
19 _SDI0
100Ω differential pair
SDI0
20
SDI0
GX4002
Ch0LF 23 _Ch0LF
Ch0VCOFILT 21 _Ch0VCOFILT
GND
24 _GND
220nF
SDA 25 _SDA
SCL 26
SCL
RS0 29 _RS0
RS1 5 _RS1
4 _NC
27 _VREG
2 10 12 18 22 28
SDO0 ^{31 SDO0}
100nF
100Ω differential pair
30
SDO0
SDO0
100nF
3
NC
To/from
controller
Ch1 Input
Ch0 Output
Figure 4-1: GX4002 Typical Application Circuit
• Place lowest value decoupling capacitor closest to the device
• Status indicator connections are shown for a LVCMOS/LVTTL compatible mode.
These I/Os can be configured as open-drain with pull-up
4.1 Power Supply Filter Recommendations
RC filters for isolating supplies are not recommended due to the large currents drawn
from each supply.
• The Ch0 and Ch1 VCOs do not have independent supplies. Both of the Ch0 and Ch1
VCOs have internal regulators sourced from Ch0VCC and Ch1VCC respectively. As
a result, additional filtering for the VCOs is not required
GX4002 2x2 14.025Gb/s Crosspoint Switch with Trace
Equalization and Output De-Emphasis
Data Sheet
55972 - 0
March 2012
53 of 74
Proprietary & Confidential