Si5341/40
Preliminary Rev. 0.9
25
4.5. Outputs
The Si5341 supports 10 differential output drivers which can be independently configured as differential or
LVCMOS. The Si5340 supports 4 output drivers independently configurable as differential or LVCMOS.
4.5.1. Output Signal Format
The differential output swing and common mode voltage are both fully programmable and compatible with a wide
variety of signal formats including LVDS and LVPECL. In addition to supporting differential signals, any of the
outputs can be configured as LVCMOS (3.3 V, 2.5 V, or 1.8 V) drivers providing up to 20 single-ended outputs, or
any combination of differential and single-ended outputs.
4.5.2. Differential Output Terminations
The differential output drivers support both AC coupled and DC coupled terminations as shown in Figure 10.
Figure 10. Supported Differential Output Terminations
4.5.3. Differential Output Swing Modes
There are two selectable differential output swing modes: Normal and High. Each output can support a unique
mode.
Differential Normal Swing Mode:
When an output driver is configured in normal swing mode, its output swing
is selectable as one of 7 settings ranging from 200 mVpp_se to 800 mVpp_se in increments of 100 mV. The
output impedance in the Normal Swing Mode is 100
differential
Any of the terminations shown in Figure 10
are supported in this mode.
Differential High Swing Mode:
When an output driver is configured in high swing mode, its output swing is
configurable as one of 7 settings ranging from 400 mVpp_se to 1600 mVpp_se in increments of 200 mV. The
output driver is in high impedance mode and supports standard 50
PCB traces. Any of the terminations shown in
Figure 10 are supported in this mode.
Note:
In this document, the terms, LVDS and LVPECL, refer to driver formats that are compatible with these signaling
standards.
100
50
50
Internally
self-biased
AC Coupled LVDS/LVPECL
50
50
AC Coupled LVPECL
VDD – 1.3V
50
50
50
50
100
DC Coupled LVDS
OUTx
OUTx
OUTx
OUTx
OUTx
OUTx
V
DDO
= 3.3V, 2.5V, 1.8V
V
DDO
= 3.3V, 2.5V
V
DDO
= 3.3V, 2.5V, 1.8V
Si5341/40
Si5341/40
Si5341/40