4.7 Output Enable/Disable
Each output driver may be individually placed in one of three operating states:
• “Enabled” state is the normal state for output clock operation. The output clock is toggling and the differential common mode voltage
will be generated, if selected by the output format.
• “Disabled” state gates off clock operation and places the output into a static, user-selectable, logic state. Differential output common
mode voltage is maintained, if selected by the output format, allowing a quick transition back to Enabled state operation with minimal
common mode disruption.
• “Powerdown” state removes power from the output driver and leaves the output pins high-impedance. In this state, regardless of
output format, the output common mode voltage is not generated and the output pin voltages are not well defined. Powerdown is
recommended for unused outputs as well as startup or long-term power reduction, where differential common voltage generation
restart will not introduce issues in the system. For lowest noise during operation, unused LVCMOS output pins should be AC
terminated to ground with 50 Ω. See
10.1 Power Management Features
for more information on powerdown.
The OEb pin provides a convenient method of enabling or disabling all of the output drivers at the same time. Holding the OEb pin
low enables all of the outputs, while driving it high disables all outputs. In addition to pin control, flexible register controls described in
the following sections allow further customization for each application. Note that any one disable control can disable the corresponding
output(s) even if all other sources controls are enabled. See the sections below, especially
4.7.5 Output Driver Disable Source
, for more information on manual and automatic disable controls.
Table 4.12. Output Enable/Disable Manual Control Registers
Register Name
Hex Address
[Bit Field]
Function
OUTALL_DISABLE_LOW
0x0102[0]
Enable/Disable all output drivers. If the
OEb pin is held high, then all outputs will
be disabled regardless of the state of this
or the OUTx_OE register bits.
0: Disable All outputs (default)
1: Enable All outputs
OUT0A_OE
0x0103[1]
Enable/Disable individual outputs. Note
that the OEb pin must be held low and
OUTALL_DISABLE_LOW = 1 in order to
enable an output.
0: Disable Output (default)
1: Enable Output
OUT0_OE
0x0108[1]
OUT1_OE
0x010D[1]
OUT2_OE
0x0112[1]
OUT3_OE
0x0117[1]
OUT4_OE
0x011C[1]
OUT5_OE
0x0121[1]
OUT6_OE
0x0126[1]
OUT7_OE
0x012B[1]
OUT8_OE
0x0130[1]
OUT9_OE
0x0135[1]
OUT9A_OE
0x013A[1]
Si5386 Rev. E Reference Manual • Output Clocks
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com
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Rev. 1.2 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • December 9, 2021
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