ACS8946 Semtech Corporation, ACS8946 Datasheet - Page 5

• Manufacturer Part Number: ACS8946
• Description: Jitter Attenuating, Multiplying Phase Locked Loop, with Protection Switch, for Oc-12/stm-4 and GbE
• Manufacturer: Semtech Corporation

Table 3 Functional Pins (cont...)
Revision 3/November 2006 © Semtech Corp.
ADVANCED COMMUNICATIONS
15
16
17
18
19
20
21
22
23
Pin No.
CFG_OUT2
ALARMC_CO3
LOCKB
CFG_IN0
CFG_IN1
CFG_IN2
CFG_IN3
CFG_IN4
CFG_IN5
Symbol
I/O
O
O
O
I
I
I
I
I
I
LVCMOS
LVCMOS
LVCMOS
LVCMOS
LVCMOS
LVCMOS
LVCMOS
LVCMOS
Schmitt
LVTTL/
LVTTL/
LVTTL/
LVTTL/
LVTTL/
Trigger
LVTTL/
LVTTL/
LVTTL/
Analog
Type
D
D
D
D
D
D
Configuration pin, used in the configuration on power-up of expected input clock
frequency and Resync selection, by connecting to appropriate pin from the CFG_IN[0:7]
pins as required. See “Configuration” on page 13.
Activity alarm output for the currently selected input reference clock. Active high; high
indicating clock failure. It is also used to configure the device at power-up, where it is
used as a configuration output pin that may be connected to CFG_IN[0:7] input pins as
required. See “Configuration” on page 13.
Lock detect output. This is a pulse-width modulated output current, with each pulse
typically +10 µA. The output produces a pulse with a width in proportion to the phase
error seen at the internal phase detector. This pin should be connected via an external
parallel capacitor and resistor to ground. The pin voltage will then give an indication of
phase lock: When low, the device is phase locked; when high the device has frequent
large phase errors and so is not phase locked. The value of the RC components used
determines the time and level of consistency required for lock indication. If LOCKB is
disabled by configuration the LOCKB output is held low.
Configuration pin for setting up the device just after power-up or after a system reset (via
pin 40, RESETB). This configuration pin is analyzed during the configuration phase, just
after power-up, so that the device works out whether this pin is connected to ground,
power, or one of the configuration outputs at pins 13 to 16. This pin is used with pin 19
to set the available output rates as shown in Table 11.
Configuration pin for setting up the device just after power-up or after a system reset (via
pin 40, RESETB). This configuration pin is analyzed during the configuration phase, just
after power-up, so that the device works out whether this pin is connected to ground,
power, or one of the configuration outputs at pins 13 to 16. This pin is used with pin 18
to set the available output rates as shown in Table 11.
Configuration pin for setting up the device just after power-up or after a system reset (via
pin 40, RESETB). This configuration pin is analyzed during the configuration phase, just
after power-up, so that the device works out whether this pin is connected to ground,
power, or one of the configuration outputs at pins 13 to 16. This pin is used with pin 21
to set the input divider and output pad mode (CML or LVPECL) configuration for OUT1
and OUT2 as in Table 10.
Configuration pin for setting up the device just after power-up or after a system reset (via
pin 40, RESETB). This configuration pin is analyzed during the configuration phase, just
after power-up, so that the device works out whether this pin is connected to ground,
power, or one of the configuration outputs at pins 13 to 16. This pin is used with pin 20
to set the input divider and output pad mode (CML or LVPECL) configuration for OUT1
and OUT2 as in Table 10.
Configuration pin for setting up the device just after power-up or after a system reset (via
pin 40, RESETB). This configuration pin is analyzed during the configuration phase, just
after power-up, so that the device works out whether this pin is connected to ground,
power or one of the configuration outputs at pins 13 to 16. This pin is used with pin 23 to
set the clock edge used for SYNC sampling, and the output clock frequency of OUT3 (pins
8 and 9) and OUT4 (pins 11 and 12), as shown in Table 12.
Configuration pin for setting up the device just after power-up or after a system reset (via
pin 40, RESETB). This configuration pin is analyzed during the configuration phase, just
after power-up, so that the device works out whether this pin is connected to ground,
power or one of the configuration outputs at pins 13 to 16. This pin is used with pin 22 to
set the clock edge used for SYNC sampling, and the output clock frequency of OUT3 (pins
8 and 9) and OUT4 (pins 11 and 12), as shown in Table 12.
FINAL
Page 5
Description
ACS8946 JAM PLL
DATASHEET
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