Si5345-44-42-D-RM
38
Rev. 1.0
6.3.3. Programmable Common Mode Voltage for Differential Outputs
The common mode voltage (VCM) for the differential Normal and High Swing modes is programmable in 100 mV
increments from 0.7 to 2.3 V depending on the voltage available at the output's VDDO pin. Setting the common
mode voltage is useful when dc coupling the output drivers. High swing mode may also cause an increase in the
rise/fall time.
Table 20. Differential Output Voltage Swing Control Registers
Register Name
Hex Address [Bit Field]
Function
Si5345
Si5344
Si5342
OUT0_AMPL
0x010A[6:4]
0x0114[6:4]
0x0114[6:4]
Sets the voltage
swing for the differ-
ential output drivers
for both normal and
high swing modes.
OUT1_ AMPL
0x010F[6:4]
0x0119[6:4]
0x0119[6:4]
OUT2_ AMPL
0x0114[6:4]
0x0128[6:4]
—
OUT3_ AMPL
0x0119[6:4]
0x012D[6:4]
—
OUT4_ AMPL
0x011E[6:4]
—
—
OUT5_ AMPL
0x0123[6:4]
—
—
OUT6_ AMPL
0x0128[6:4]
—
—
OUT7_ AMPL
0x012D[6:4]
—
—
OUT8_ AMPL
0x0132[6:4]
—
—
OUT9_ AMPL
0x013C[6:4]
—
—
Table 21. Differential Output Common Mode Voltage Control Registers
Register Name
Hex Address [Bit Field]
Function
Si5345
Si5344
Si5342
OUT0_CM
0x010A[3:0]
0x0114[3:0]
0x0114[3:0]
Sets the common
mode voltage for the
differential output
driver.
OUT1_ CM
0x010F[3:0]
0x0119[3:0]
0x0119[3:0]
OUT2_ CM
0x0114[3:0]
0x0128[3:0]
—
OUT3_ CM
0x0119[3:0]
0x012D[3:0]
—
OUT4_ CM
0x011E[3:0]
—
—
OUT5_ CM
0x0123[3:0]
—
—
OUT6_ CM
0x0128[3:0]
—
—
OUT7_ CM
0x012D[3:0]
—
—
OUT8_ CM
0x0132[3:0]
—
—
OUT9_ CM
0x013C[3:0]
—
—