1
Precision EdgeTM
SY58020U
Micrel
DESCRIPTION
Precision 1:4, 400mV CML fanout buffer
Guaranteed AC performance over temperature/
voltage:
> 6GHz f
MAX
clock
< 60ps t
r
/ t
f
times
< 250ps t
pd
< 15ps max. skew
Low jitter performance:
< 10ps
(pk-pk)
total jitter (clock)
< 1ps
(rms)
random jitter (data)
< 10ps
(pk-pk)
deterministic jitter (data)
Accepts an input signal as low as 100mV
Unique input termination and V
T
pin accepts
DC-coupled and AC-coupled differential
inputs: LVPECL, LVDS, and CML
50
source terminated CML outputs
Power supply 2.5V
5% and 3.3V
10%
Industrial temperature range: 40
C to +85
C
Available in 16-pin (3mm
3mm) MLFTM package
FEATURES
6GHz, 1:4 CML FANOUT
BUFFER/TRANSLATOR WITH
INTERNAL I/O TERMINATION
Precision EdgeTM
SY58020U
APPLICATIONS
s All SONET and All GigE clock distribution
s
Fibre Channel clock and data distribution
s
Backplane distribution
s
Data distribution: OC-48, OC-48+FEC, XAUI
s
High-end, low skew, multiprocessor synchronous
clock distribution
Rev.: A
Amendment: /0
Issue Date:
July 2003
The SY58020U is a 2.5V/3.3V precision, high-speed, fully
differential 1:4 CML fanout buffer. Optimized to provide four
identical output copies with less than 15ps of skew and less
than 10ps
(pk-pk)
total jitter, the SY58020U can process clock
signals as fast as 6GHz.
The differential input includes Micrel's unique, 3-pin input
termination architecture interfaces to differential LVPECL,
LVDS, and CML signals (AC-coupled or DC-coupled) as
small as 100mV without any level-shifting or termination
resistor networks in the signal path. For AC-coupled input
interface applications, an on-board output reference voltage
(V
REF-AC
) is provided to bias the V
T
pin. The outputs are
optimized to drive 400mV typical swing into 50
loads, with
extremely fast rise/fall times guaranteed to be less than
60ps.
The SY58020U operates from a 2.5V
5% supply or
3.3V
10% supply and is guaranteed over the full industrial
temperature range (40
C to +85
C). For applications that
require LVPECL outputs, consider the SY58021U or
SY58022U 1:4 fanout buffer with 800mV and 400mV output
swing, respectively. The SY58020U is part of Micrel's high-
speed, Precision EdgeTM product line. Data sheets and
support documentation can be found on Micrel's web site at
www.micrel.com.
Precision Edge is a trademark of Micrel, Inc.
Micro
LeadFrame and MLF are trademarks of Amkor Technology, Inc.
Precision EdgeTM
FUNCTIONAL BLOCK DIAGRAM
TYPICAL PERFORMANCE
IN
/IN
Q1
/Q1
Q0
/Q0
V
T
50
50
V
REF-AC
Q3
/Q3
Q2
/Q2
2GHz Output
TIME (70ps/div.)
Amplitude (100mV/div
.)
2
Precision EdgeTM
SY58020U
Micrel
PACKAGE/ORDERING INFORMATION
Ordering Information
(Note 1)
Package
Operating
Package
Part Number
Type
Range
Marking
SY58020UMI
MLF-16
Industrial
020U
SY58020UMITR
(Note 2)
MLF-16
Industrial
020U
Note 1.
Contact factory for die availability. Die are guaranteed at T
A
=
25
C, DC electricals only.
Note 2.
Tape and Reel.
Pin Number
Pin Name
Pin Function
1, 4
IN, /IN
Differential Input: This input pair receives the signal to be buffered. Each pin of this pair
internally terminates with 50
to the V
T
pin. Note that this input will default to an
indeterminate state if left open. See
"Input Interface Applications"
section.
2
VT
Input Termination Center-Tap: Each input terminates to this pin. The V
T
pin provides a
center-tap for each input (IN, /IN) to the termination network for maximum interface
flexibility. See
"Input Interface Applications"
section.
3
VREF-AC
Reference Output Voltage: This output biases to V
CC
1.2V. It is used when AC-coupling
to differential inputs. Connect V
REF-AC
directly to the V
T
pin. Bypass with 0.01
F low ESR
capacitor to V
CC
. See
"Input Interface Applications"
section.
8, 13
VCC
Positive Power Supply: Bypass with 0.1
F//0.01
F low ESR capacitors as close to the
pins as possible.
5, 16
GND,
Ground. Exposed pad must be connected to a ground plane that is the same potential
Exposed Pad
as the ground pin.
14, 15
/Q0, Q0,
CML Differential Output Pairs: Differential buffered output copy of the input signal. The
11, 12
/Q1, Q1,
output swing is typically 400mV into 50
load. Normally terminate CML output pairs with
9, 10
/Q2, Q2,
100
across Q and /Q outputs at the receiving end. Unused output pairs may be left
6, 7
/Q3, Q3,
floating with no impact on jitter or skew. See
"CML Output Termination"
section.
PIN DESCRIPTION
1
2
3
4
12
11
10
9
16 15 14 13
5
6
7
8
IN
VT
VREF-AC
/IN
Q1
/Q1
Q2
/Q2
VCC
/Q0
Q0
GND
VCC
Q3
/Q3
GND
16-Pin MLFTM (MLF-16)
3
Precision EdgeTM
SY58020U
Micrel
Absolute Maximum Ratings
(Note 1)
Power Supply Voltage (V
CC
) ....................... 0.5V to +4.0V
Input Voltage (V
IN
) ......................................... 0.5V to V
CC
CML Output Voltage (V
OUT
) ........... V
CC
1.0V to V
CC
+0.5V
Current (V
T
)
Source or sink current on V
T
pin ........................
100mA
Input Current
Source or sink current on IN, /IN ..........................
50mA
Current (V
REF
)
Source or sink current on V
REF-AC
, Note 4 .........
1.5mA
Operating Ratings
(Note 2)
Supply Voltage (V
CC
) ............................ +2.375V to +3.60V
Operating Temperature Range (T
A
) ........... 40
C to +85
C
Package Thermal Resistance
MLFTM
(
JA
)
Still-Air ............................................................. 60
C/W
500lfpm ............................................................ 54
C/W
MLFTM
(
JB
)
(Junction-to-Board Resistance), Note 3 .......... 33
C/W
Lead Temperature Soldering, (10 seconds) .............. 270
C
Storage Temperature Range (T
STORE
) .... 65
C to +150
C
T
A
= 40
C to +85
C
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
CC
Power Supply Voltage
V
CC
= 2.5V
2.375
2.5
2.625
V
V
CC
= 3.3V
3.0
3.3
3.60
V
I
CC
Power Supply Current
No load, V
CC
= max.
150
180
mA
(includes internal 50
pull-up)
V
IH
Input HIGH Voltage
Note 6
V
CC
1.6
V
CC
V
V
IL
Input LOW Voltage
0
V
IH
0.1
V
V
IN
Input Voltage Swing
See Figure 1a
0.1
1.7
V
V
DIFF_IN
Differential Input Voltage Swing
See Figure 1b
0.2
3.4
V
R
IN
IN-to-V
T
Resistance
40
50
60
V
REF-AC
Output Reference Voltage
V
CC
1.3 V
CC
1.2 V
CC
1.1
V
V
T IN
IN-to-V
T
Voltage
1.28
V
DC ELECTRICAL CHARACTERISTICS
(Notes 5)
V
CC
= 3.3V
10% or 2.5V
5%; R
L
= 100
across each output pair or equivalent; T
A
= 40
C to +85
C, unless otherwise stated.
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
OH
Output HIGH Voltage
V
CC
0.020 V
CC
0.010
V
CC
V
V
OUT
Output Voltage Swing
see Figure 1a
325
400
500
mV
V
DIFF_OUT
Differential Output Voltage Swing
see Figure 1b
650
800
1000
mV
R
OUT
Output Source Impedance
40
50
60
Note 1.
Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation
is not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM
RATINGS conditions for extended periods may affect device reliability.
Note 2.
The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
Note 3.
Thermal performance assumes exposed pad is soldered (or equivalent) to the device's most negative potential on the PCB.
Note 4.
Due to the limited drive capability, use for input of the same package only.
Note 5.
The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
Note 6.
V
IH
(min.) not lower than 1.2V.
CML DC ELECTRICAL CHARACTERISTICS
(Notes5)
4
Precision EdgeTM
SY58020U
Micrel
TIMING DIAGRAM
SINGLE-ENDED AND DIFFERENTIAL SWINGS
V
IN
,
V
OUT
400mV
Figure 1a. Single-Ended Voltage Swing
V
DIFF_IN
,
V
DIFF_OUT
800mV
Figure 1b. Differential Voltage Swing
/IN
IN
/Q
Q
t
pd
V
CC
= 2.5V
5% or 3.3V
10%; T
A
= 40
C to +85
C; R
L
= 100
across each output pair or equivalent, unless otherwise stated.
Symbol
Parameter
Condition
Min
Typ
Max
Units
f
MAX
Maximum Operating Frequency
V
OUT
200mV
Clock
6
GHz
NRZ Data
10
Gbps
t
pd
Propagation Delay
110
180
260
ps
t
CHAN
Channel-to-Channel Skew
Note 7
4
15
ps
t
SKEW
Part-to-Part Skew
Note 8
50
ps
t
JITTER
Clock
Cycle-to-Cycle Jitter
Note 9
1
ps(rms)
Total Jitter
Note 10
10
ps(pk-pk)
Data
Random Jitter
Note 11
2.5Gbps 3.2Gbps
1
ps(rms)
Deterministic Jitter
Note 12
2.5Gbps 3.2Gbps
10
ps(pk-pk)
t
r
, t
f
Output Rise/Fall Time 20% to 80%
At full swing
20
40
60
ps
Note 7.
Skew is measured between outputs of the same bank under identical transitions.
Note 8.
Skew is defined for two parts with identical power supply voltages at the same temperature and with no skew of the edges at the respective inputs.
Note 9.
Cycle-to-cycle jitter definition: The variation of periods between adjacent cycles, T
n
T
n1
where T is the time between rising edges of the
output signal.
Note 10. Total jitter definition: With an ideal clock input of frequency
f
MAX
, no more than one output edge in 10
12
output edges will deviate by more
than the specified peak-to-peak jitter value.
Note 11. Random jitter is measured with a K28.7 comma detect character pattern, measured at 2.5Gbps/3.2Gbps.
Note 12. Deterministic jitter is measured at 2.5Gbps/3.2Gbps with both K28.5 and 2
23
1 PRBS pattern
AC ELECTRICAL CHARACTERISTICS
5
Precision EdgeTM
SY58020U
Micrel
TYPICAL OPERATING CHARACTERISTICS
0
50
100
150
200
250
300
350
400
450
500
0
2000
4000
6000
8000
10000
12000
AMPLITUDE (V)
FREQUENCY (MHz)
Amplitude
vs. Frequency
0
1
2
3
4
5
6
7
-60 -40 -20 0
20 40 60 80 100
SKEW (ps)
TEMPERATURE (
C)
Skew
vs. Temperature
V
CC
= 2.5V, GND = 0, V
IN
= 100mV, T
A
= 25
C, unless otherwise stated.
165
170
175
180
185
190
195
0
200 400 600 800 1000 1200
PROPAGATION DELAY (ps)
INPUT VOLTAGE SWING (mV)
Propagation Delay vs.
Input Voltage Swing
176
177
178
179
180
181
182
183
184
-60 -40 -20 0
20 40 60 80 100
PROPAGATION DELAY (ps)
TEMPERATURE (
C)
Propagation Delay vs.
Temperature
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