sy87700al Micrel Semiconductor, sy87700al Datasheet - Page 3

• Manufacturer Part Number: sy87700al
• Description: Sy87700al Sy87700 Low-power, 3.3v, 32mbps To 208mbps Anyrate Clock And Data Recovery
• Manufacturer: Micrel Semiconductor

August 2007
Pin Description
Inputs
Outputs
Pin Number
(28-SOIC)
22, 21
19, 18
11, 12
16, 15
27
26
17
25
24
4,
5
7
6
8
9
3
2
Pin Number
(32-TQFP)
21, 20
18, 17
15, 14
9, 10
26
32
25
16
31
24
23
2,
3
5
4
6
7
FREQSEL1
FREQSEL2
FREQSEL3
Pin Name
RDOUTP
RDOUTN
DIVSEL1
DIVSEL2
REFCLK
CLKSEL
RCLKP,
TCLKP,
RDINP,
RCLKN
PLLSP,
PLLRP,
TCLKN
PLLRN
RDINN
PLLSN
LFIN
CD
Pin Name
Serial Data Input. Differential PECL: These built-in line receiver inputs are
connected to the differential receive serial data stream. An internal receive
PLL recovers the embedded clock (RCLK) and data (RDOUT) information.
The incoming data rate can be within one of eight frequency ranges
depending on the state of the FREQSEL pins. See “Frequency Selection”
Table.
Reference Clock. TTL Input: This input is used as the reference for the
internal frequency synthesizer and the “training” frequency for the receiver
PLL to keep it centered in the absence of data coming in on the RDIN inputs
Carrier Detect. PECL Input: This input controls the recovery function of the
Receive PLL and can be driven by the carrier detect output of optical
modules or from external transition detection circuitry. When this input is
HIGH the input data stream (RDIN) is recovered normally by the Receive
PLL. When this input is LOW the data on the inputs RDIN will be internally
forced to a constant LOW, the data outputs RDOUT will remain LOW, the
Link Fault Indicator output LFIN forced LOW and the clock recovery PLL
forced to lock onto the clock frequency generated from REFCLK.
Frequency Select. TTL Inputs: These inputs select the output clock frequency
range as shown in the “Frequency Selection” Table.
Divider Select. TTL Inputs: These inputs select the ratio between the output
clock frequency (RCLK/TCLK) and the REFCLK input frequency as shown in
the “Reference Frequency Selection” Table.
Clock Select. TTL Input: This input is used to select either the recovered
clock of the receiver PLL (CLKSEL = HIGH) or the clock of the frequency
synthesizer (CLKSEL = LOW) to the TCLK outputs.
Link Fault Indicator. TTL Output: This output indicates the status of the input
data stream RDIN. Active HIGH signal is indicating when the internal clock
recovery PLL has locked onto the incoming data stream. LFIN will go HIGH if
CD is HIGH and RDIN is within the frequency range of the Receive PLL
(1000ppm). LFIN is an asynchronous output.
Receive Data Output. Differential PECL: These ECL 100k outputs represent
the recovered data from the input data stream (RDIN). This recovered data is
specified against the rising edge of RCLK.
Clock Output. Differential PECL: These ECL 100k outputs represent the
recovered clock used to sample the recovered data (RDOUT).
Clock Output. Differential PECL: These ECL 100k outputs represent either
the recovered clock (CLKSEL = HIGH) used to sample the recovered data
(RDOUT) or the transmit clock of the frequency synthesizer (CLKSEL =
LOW).
Clock Synthesis PLL Loop Filter: External loop filter pins for the clock
synthesis PLL.
Clock Recovery PLL Loop Filter: External loop filter pins for the receiver PLL.
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