SI5110 Silicon Storage Technology Inc, SI5110 Datasheet - Page 19

• Manufacturer Part Number: SI5110
• Description: SiPHY OC-48/STM-16 SONET/SDH TRANSCEIVER
• Manufacturer: Silicon Storage Technology Inc

Number(s)
E10, F10
Pin
G8
C4
B5
K2
A2
F3
J7
PHASEADJ
REFRATE
REFCLK,
REFCLK
REFSEL
Name
LPTM
LTR
NC
NC
I/O
I
I
I
I
I
I
Signal Level
Preliminary Rev. 0.41
LVPECL
LVTTL
LVTTL
LVTTL
LVTTL
Loop Timed Operation.
When this input is forced high, the recovered clock
from the receiver is divided down and used as the ref-
erence source for the transmit CMU. The narrowband
setting for the DSPLL CMU will be sufficient to provide
SONET compliant jitter generation and transfer on the
transmit data and clock outputs (TXDOUT,TXCLK-
OUT). This pin should be held low for normal opera-
tion.
Lock-to-Reference.
This input forces a stable output clock by locking
RXCLK1 and RXCLK2 to the provided reference.
Driving LTR low activates this feature.
No Connect.
Reserved for device testing. Leave electrically
unconnected.
No Connect.
Reserved for device testing. Leave electrically uncon-
nected.
Sampling Phase Adjust.
Applying an analog voltage to this pin allows adjust-
ment of the sampling phase across the data eye. Tie-
ing this input high nominally centers the sampling
phase.
Differential Reference Clock.
The reference clock sets the operating frequency of
the PLL used to generate the high speed transmit
clock. In addition, REFCLK sets the initial operating
frequency used by the onboard PLL for clock and data
recovery. The Si5110 will operate with reference clock
frequencies that are either 1/16 or 1/32 the serial data
rate (nominally 155 MHz or 78 MHz).
Reference Clock Select.
This input configures the Si5110 to operate with one of
two reference clock frequencies. If REFRATE is held
high, the device requires a reference clock that is 1/16
the serial data rate. If REFRATE is low, a reference
clock at 1/32 the serial data rate is required.
Reference Clock Selection.
This inputs selects the reference clock source used by
the CMU. When REFSEL = 0, the low speed data
input clock, TXCLK4IN, is used as the CMU refer-
ence. When REFSEL = 0, the reference clock pro-
vided on REFCLK is used.
Description
Si5110
19