Skyworks Si5341 - Differential Output Terminations; Differential Amplitude Controls

5.3.1 Differential Output Terminations
The differential output drivers support both ac-coupled and dc-coupled terminations as shown in the figure below.
AC Coupled LVDS/LVPECL
AC Coupled CMLDC Coupled LVDS
AC Coupled HCSL
VDD
RX
Standard
HCSL
Receiver
R1
OUTx
OUTxb
R1
R2
R2
V
DDO
= 3.3V, 2.5V. 1.8V
50
50
50
50
VDD – 1.3V
5050
OUTx
OUTxb
V
DDO
= 3.3V, 2.5V
50
50
100
OUTx
OUTxb
LVDS: V
DDO
= 3.3V, 2.5V, 1.8V
100
50
50
Internally
self-biased
OUTx
OUTxb
LVDS: V
DDO
= 3.3V, 2.5V, 1.8V
LVPECL: V
DDO
= 3.3V, 2.5V
VDD
RX
R1 R2
3.3 V
2.5 V
1.8 V
442
332
243
56.2
59.0
63.4
For V
CM
= 0.35 V
*All caps should have < 5 ohms capacitive reactance at the clock output frequency
0.1uF*
0.1uF*
0.1uF*
0.1uF*
0.1uF*
0.1uF*
Figure 5.1. Supported Differential Output Terminations
5.3.2 Differential Amplitude Controls
The differential amplitude of each output can be controlled with the following registers. See XREF Appendix A for register settings for
non-standard amplitudes.
Table 5.3. Differential Output Voltage Swing (Amplitude) Control Registers
Setting Name
Hex Address [Bit Field]
Function
Si5341 Si5340
OUT0_AMPL
OUT1_AMPL
OUT2_AMPL
OUT3_AMPL
OUT4_AMPL
OUT5_AMPL
OUT6_AMPL
OUT7_AMPL
OUT8_AMPL
OUT9_AMPL
010A[6:4]
010F[6:4]
0114[6:4]
0119[6:4]
011E[6:4]
0123[6:4]
0128[6:4]
012D[6:4]
0132[6:4]
013C[6:4]
0114[6:4]
0119[6:4]
0128[6:4]
012D[6:4]
—
—
—
—
—
—
Sets the voltage swing (amplitude) for the differential output driv-
ers when in Normal differential format and Low Power differential
format (Table 5.4 Settings for LVDS, LVPECL, and HCSL on page
25).
Si5341, Si5340 Rev D Family Reference Manual • Output Clocks
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
24 Rev. 1.3 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • July 26, 2021 24