SY87725LHY Micrel Inc, SY87725LHY Datasheet - Page 14

• Manufacturer Part Number: SY87725LHY
• Description: 3.3V ONU SERDES (I Temp, /60 Pin EP-TQFP/T+R)
• Manufacturer: Micrel Inc
• Type: Transceiverr

Specifications of SY87725LHY

• Protocol: LVDS
• Voltage - Supply: 3.15 V ~ 3.45 V
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP Exposed Pad, 64-eTQFP, 64-HTQFP, 64-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Drivers/receivers: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-2544; SY87725LHY

Applications Sections
This section illustrates the various operating modes of
the SY87725L with the appropriate control signals.
Normal Data Flow
Receive Section
The diagram below shows the data paths in a normal
operating mode. In this case, downstream data at a
serial rate of 2.5Gbps is arriving at SIN and the
recovered 4-bit parallel data is exiting at DOUT at
625Mbps. This is not the double data rate mode
(DDR) so the parallel rate is the serial rate ÷ 4.
July 2007
RCV_CNTRL0
1
RCV_FSEL0
1
RCV_CNTRL1
Table 7. Loopback and DDR Select Control Signals
Table 8. Transmit and Receive Frequency Select
1
RCV_FSEL1
Figure 4. Normal Data Flow
1
XMT_CNTRL0
1
XMT_FSEL0
14
Transmit Section
On the transmit side, the upstream data appears at
DIN in a 4-bit wide parallel format at 312.5Mbps and
exits at SOUT at a 1.25Gbps serial rate. The CLKIN
input is synchronous with the parallel data at DIN.
The loopback control signals RCV_CNTRL0,
RCV_CNTRL1, XMT_CNTRL0, XMT_CNTRL1 shown
in the table below select the clock and data paths for
normal operation. The RCV_DDRSel input is selecting
the CLKOUT to be in normal rate (÷ 4) mode.
0
XMT_CNTRL1
1
XMT_FSEL1
[e-mail]
1
RCV_DDRSEL
0
or [phone]
M9999-071007-B