SI5110 Datasheet, PDF (22/26 Pages) Silicon Laboratories – SiPHY™ OC-48/STM-16 SONET/SDH TRANSCEIVER

Si5110
Pin
Number(s)
G9–10, H9–
10, J9–10,
K9–10
Name
TXDIN[3:0],
TXDIN[3:0]
H1, J1
TXDOUT,
TXDOUT
K4
TXLOL
H4
TXMSBSEL
K3
TXREXT
J6
TXSQLCH
D4–7, E4–6,
F4–6, G4–7
G2
VDD
VDD33
B4
VREF
I/O Signal Level
Description
I
LVDS
Differential Parallel Data Input.
The 4-bit data word present on these pins is multi-
plexed into a high speed serial stream and output on
TXDOUT. The data on these inputs is clocked into the
device by the rising edge of TXCLK4IN.
O
CML
Differential High Speed Data Output.
The 4-bit word input on TXDIN[3:0] is multiplexed into
a high speed serial stream that is output on these
pins. Input data is multiplexed in sequence from
TXDIN0 to TXDIN3 with TXDIN0 transmitted first. This
output is updated by the rising edge of TXCLKOUT.
O
LVTTL
CMU Loss-of-Lock.
The output is asserted low when the CMU is not
phase locked to the selected reference source.
I
LVTTL
Data Bus Transmit Order.
For TXMSBSEL = 0, data on TXDIN[0] is transmitted
first followed by TXDIN[1] through TXDIN[3].
For TXMSBSEL = 1, TXDIN[3] is transmitted first fol-
lowed by TXDIN[2] through TXDIN[0].
External Bias Resistor.
This resistor is used by the transmitter circuitry to
establish bias currents within the device. This pin must
be connected to GND through a 3.09 kΩ (1%) resistor.
I
LVTTL
Transmit Data Squelch.
If TXSQLCH is asserted low, the output data stream
on TXDOUT will be forced to 0s. If TXSQLCH = 1, TX
squelching is turned off.
VDD
1.8 V
Supply Voltage.
Nominally 1.8 V.
VDD33
1.8 V or 3.3 V
Digital Output Supply.
Must be tied to either 1.8 V or 3.3 V. When tied to
3.3 V, LVTTL compatible output voltage swings on
RXLOL, LOS, TXLOL, and FIFOERR are supported.
O
Voltage Ref ^{Voltage Reference.}
The Si5110 provides an output voltage reference that
can be used by an external circuit to set the LOS
threshold, slicing level, or sampling phase adjustment.
The equivalent resistance between this pin and GND
should not be less than 10 kΩ. The reference voltage
is nominally 1.25 V.
22
Preliminary Rev. 0.41