Micrel, Inc.
3.3V 32-175Mbps AnyRate
®
CLOCK AND DATA RECOVERY
Use lower-power SY87700AL for new designs
DESCRIPTION
SY87700L
SY87700L
FEATURES
■
■
■
■
Industrial temperature range (–40
°
C to +85
°
C)
3.3V power supply
SONET/SDH/ATM compatible
Clock and data recovery from 32Mbps up to
175Mbps NRZ data stream, clock generation from
32Mbps to 175Mbps
■
Two on-chip PLLs: one for clock generation and
another for clock recovery
■
Selectable reference frequencies
■
Differential PECL high-speed serial I/O
■
Line receiver input: no external buffering needed
■
Link Fault indication
■
100k ECL compatible I/O
■
Complies with Bellcore, ITU/CCITT and ANSI
specifications for applications such as OC-1 and
OC-3 as well as proprietary applications
■
Available in 32-pin EPAD-TQFP and 28-pin SOIC
packages (28-pin SOIC is available, but is not
recommended for new designs.)
The SY87700L is a complete Clock Recovery and Data
Retiming integrated circuit for data rates from 32Mbps
up to 175Mbps NRZ. The device is ideally suited for
SONET/SDH/ATM applications and other high-speed data
transmission systems.
Clock recovery and data retiming is performed by
synchronizing the on-chip VCO directly to the incoming
data stream. The VCO center frequency is controlled by
the reference clock frequency and the selected divide
ratio. On-chip clock generation is performed through the
use of a frequency multiplier PLL with a byte rate source
as reference.
The SY87700L also includes a link fault detection
circuit.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
APPLICATIONS
■
SONET/SDH/ATM OC-1 and OC-3
■
Fast Ethernet, SMPTE 259
■
Proprietary architecture up to 175Mbps
BLOCK DIAGRAM
PLLR P/N
RDOUTP
(PECL)
RDOUTN
0
1
PHASE/
FREQUENCY
DETECTOR
LINK
FAULT
DETECTOR
RDINP
(PECL)
RDINN
PHASE
DETECTOR
CHARGE
PUMP
VCO
RCLKP
(PECL)
RCLKN
CD
(PECL)
REFCLK
(TTL)
LFIN
(TTL)
PHASE/
FREQUENCY
DETECTOR
CHARGE
PUMP
VCO
1
0
TCLKP
(PECL)
TCLKN
DIVIDER
BY 8, 10, 16, 20
SY87700L
DIVSEL 1/2
(TTL)
PLLS P/N
FREQSEL 1/2/3
(TTL)
CLKSEL
(TTL)
V
CC
V
CCA
V
CCO
GND
AnyRate is a registered trademark of Micrel, Inc.
M9999-111406
hbwhelp@micrel.com or (408) 955-1690
Rev.: H
Amendment: /0
1
Issue Date: September 2006
Micrel, Inc.
SY87700L
PACKAGE/ORDERING INFORMATION
Ordering Information
(1)
VCCA 1
LFIN 2
DIVSEL1 3
RDINP 4
RDINN 5
FREQSEL1 6
REFCLK 7
FREQSEL2 8
FREQSEL3 9
N/C 10
PLLSP 11
PLLSN 12
GND 13
GND 14
28 VCC
27 CD
26 DIVSEL2
25 RDOUTP
24 RDOUTN
23 VCCO
22 RCLKP
21 RCLKN
20 VCCO
19 TCLKP
18 TCLKN
17 CLKSEL
16 PLLRP
15 PLLRN
Part Number
SY87700LZI
SY87700LZITR
(2)
SY87700LHI
SY87700LHITR
(2)
SY87700LZG
(3)
SY87700LZGTR
(2, 3)
SY87700LHG
SY87700LHGTR
(2, 3)
Package Operating
Type
Range
Z28-1
Z28-1
H32-1
H32-1
Z28-1
Z28-1
H32-1
H32-1
Industrial
Industrial
Industrial
Industrial
Industrial
Industrial
Industrial
Industrial
Package
Marking
SY87700LZI
SY87700LZI
SY87700LHI
SY87700LHI
Lead
Finish
Sn-Pb
Sn-Pb
Sn-Pb
Sn-Pb
SY87700LZG with
NiPdAu
Pb-Free bar line indicator Pb-Free
SY87700LZG with
NiPdAu
Pb-Free bar line indicator Pb-Free
SY87700LHG with
NiPdAu
Pb-Free bar line indicator Pb-Free
SY87700LHG with
NiPdAu
Pb-Free bar line indicator Pb-Free
28-Pin SOIC (Z28-1)
32 31 30 29 28 27 26 25
NC
RDINP
RDINN
FREQSEL1
REFCLK
FREQSEL2
FREQSEL3
NC
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
24
23
22
21
20
19
18
17
RDOUTP
RDOUTN
VCCO
RCLKP
RCLKN
VCCO
TCLKP
TCLKN
32-Pin EPAD TQFP (H32-1)
M9999-111406
hbwhelp@micrel.com or (408) 955-1690
PLLSP
PLLSN
GNDA
GND
GND
PLLRN
PLLRP
CLKSEL
DIVSEL1
LFIN
VCCA
VCCA
VCC
VCC
CD
DIVSEL2
Notes:
1. Contact factory for die availability. Dice are guaranteed at T
A
= 25°C, DC Electricals only.
2. Tape and Reel.
3. Pb-Free package is recommended for new designs.
2
Micrel, Inc.
SY87700L
PIN DESCRIPTIONS
Pin Number
SOIC
4
5
Pin Number
TQFP
2
3
Pin Name
RDINP,
RDINN
Pin Function
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 five frequency ranges depend-
ing on the state of the FREQSEL pins. See “Frequency Selection” table.
Reference Clock (TTL Inputs): 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 look 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 Inputs): 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.
Supply Voltage
(1)
Analog Supply Voltage
(1)
Output Supply Voltage
(1)
Ground
No Connect
7
5
REFCLK
27
26
CD
6
8
9
3
26
17
4
6
7
32
25
16
FREQSEL1,
FREQSEL2,
FREQSEL3
DIVSEL1,
DIVSEL2
CLKSEL
2
31
LFIN
25
24
22
21
19
18
24
23
21
20
18
17
RDOUTP,
RDOUTN
RCLKP,
RCLKN
TCLKP,
TCLKN
11
12
16
15
1
20, 23
13, 14
10
9
10
15
14
27, 28,
29, 30
19, 22
12, 13
1, 8
PLLSP,
PLLSN
PLLRP,
PLLRN
V
CC
V
CCA
V
CCO
GND
NC
Note:
1. V
CC
, V
CCA
, V
CCO
must be the same value.
M9999-111406
hbwhelp@micrel.com or (408) 955-1690
3
Micrel, Inc.
SY87700L
FUNCTIONAL DESCRIPTION
Clock Recovery
Clock Recovery, as shown in the block diagram generates
a clock that is at the same frequency as the incoming data
bit rate at the Serial Data input. The clock is phase aligned
by a PLL so that it samples the data in the center of the
data eye pattern.
The phase relationship between the edge transitions of
the data and those of the generated clock are compared by
a phase/frequency detector. Output pulses from the detector
indicate the required direction of phase correction. These
pulses are smoothed by an integral loop filter. The output of
the loop filter controls the frequency of the Voltage Controlled
Oscillator (VCO), which generates the recovered clock.
Frequency stability without incoming data is guaranteed
by an alternate reference input (REFCLK) that the PLL locks
onto when data is lost. If the Frequency of the incoming
signal varies by greater than approximately 1000ppm with
respect to the synthesizer frequency, the PLL will be declared
out of lock, and the PLL will lock to the reference clock.
The loop filter transfer function is optimized to enable the
PLL to track the jitter, yet tolerate the minimum transition
density expected in a received SONET data signal. This
transfer function yields a 30µs data stream of continuous
1's or 0's for random incoming NRZ data.
The total loop dynamics of the clock recovery PLL
provides jitter tolerance which is better than the specified
tolerance in GR-253-CORE.
Lock Detect
The SY87700L contains a link fault indication circuit which
monitors the integrity of the serial data inputs. If the received
serial data fails the frequency test, the PLL will be forced to
lock to the local reference clock. This will maintain the correct
frequency of the recovered clock output under loss of signal
or loss of lock conditions. If the recovered clock frequency
deviates from the local reference clock frequency by more
than approximately 1000ppm, the PLL will be declared out
of lock. The lock detect circuit will poll the input data stream
in an attempt to reacquire lock to data. If the recovered
clock frequency is determined to be within approximately
1000ppm, the PLL will be declared in lock and the lock
detect output will go active.
M9999-111406
hbwhelp@micrel.com or (408) 955-1690
4
Micrel, Inc.
SY87700L
CHARACTERISTICS
Performance
The SY87700L PLL complies with the jitter specifications
proposed for SONET/SDH equipment defined by the Bellcore
Specifications: GR-253-CORE, Issue 2, December 1995 and
ITU-T Recommendations: G.958 document, when used with
differential inputs and outputs.
Input Jitter Tolerance
Input jitter tolerance is defined as the peak-to-peak
amplitude of sinusoidal jitter applied on the input signal that
causes an equivalent 1dB optical/electrical power penalty.
SONET input jitter tolerance requirement condition is the
input jitter amplitude which causes an equivalent of 1dB
power penalty.
A
Jitter Transfer
Jitter transfer function is defined as the ratio of jitter on
the output OC-N/STS-N signal to the jitter applied on the
input OC-N/STS-N signal versus frequency. Jitter transfer
requirements are shown in Figure 2.
Jitter Generation
The jitter of the serial clock and serial data outputs shall
not exceed .01 U.I. rms when a serial data input with no
jitter is presented to the serial data inputs.
Jitter Transfer (dB)
0.1
Sinusoidal Input
Jitter Amplitude
(UI p-p)
15
1.5
-20dB/decade
-20dB/decade
-20dB/decade
-20
Acceptable
Range
0.40
f0
f1
f2
Frequency
f4
ft
fc
Frequency
OC/STS-N
Level
3
f0
(Hz)
10
f1
(Hz)
30
f2
(Hz)
300
f3
(kHz)
6.5
ft
(kHz)
65
OC/STS-N
Level
3
fc
(kHz)
130
P
(dB)
0.1
Figure 1. Input Jitter Tolerance
Figure 2. Jitter Transfer
M9999-111406
hbwhelp@micrel.com or (408) 955-1690
5
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