1
Precision EdgeTM
SY58031U
Micrel
M9999-022604
hbwhelp@micrel.com or (408) 955-1690
DESCRIPTION
s
Precision 1:8, 400mV CML fanout buffer
s
Guaranteed AC performance over temperature and
voltage:
Clock frequency range: DC to 5GHz
<65ps t
r
/ t
f
times
<300ps t
pd
<20ps skew
s
Low-jitter performance:
<10ps
pp
total jitter (clock)
<1ps
rms
random jitter
s
50
source-terminated CML outputs
s
400mV CML output swing into 50
load
s
Fully differential I/O
s
Accepts an input signal as low as 100mV
s
Unique input termination and V
T
pin accepts DC-
coupled and AC-coupled differential inputs:
(LVPECL, LVDS, and CML)
s
Power supply 2.5V
5% or 3.3V
10%
s
Industrial temperature range: 40
C to +85
C
s
Available in 32-pin (5mm
5mm) MLFTM package
FEATURES
ULTRA-PRECISION 1:8 FANOUT
BUFFER WITH 400mV CML OUTPUTS
AND INTERNAL I/O TERMINATIO
N
Precision EdgeTM
SY58031U
APPLICATIONS
s All SONET and all GigE clock distribution
s
All Fibre Channel clock and data distribution
s
Network routing engine timing distribution
s
High-end, low-skew multiprocessor synchronous
clock distribution
Rev.: A
Amendment: /0
Issue Date:
February 2004
The SY58031U is a 2.5V/3.3V precision, high-speed, fully
differential CML 1:8 fanout buffer. The SY58031U is
optimized to provide eight identical output copies with less
than 20ps of skew and less than 10ps
p-p
total jitter. It can
process clock signals as fast as 5GHz.
The differential input includes Micrel's unique, 3-pin input
termination architecture that allows the SY58031U to directly
interface to CML, LVPECL, and LVDS differential signals
(AC- or DC-coupled) without any level-shifting or termination
resistor networks in the signal path. The result is a clean,
stub-free, low-jitter interface solution. The CML outputs
feature 400mV typical swing into 50
loads and provide an
extremely fast rise/fall time guaranteed to be less than 65ps.
The SY58031U 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 high-speed 1:8 LVPECL fanout buffers, consider
the SY58032U and SY58033U. The SY58031U is part of
Micrel's high-speed, Precision EdgeTM product line.
All support documentation can be found on Micrel's web
site at www.micrel.com.
FUNCTIONAL BLOCK DIAGRAM
Precision Edge is a trademark of Micrel, Inc.
Micro
LeadFrame and MLF are trademarks of Amkor Technology, Inc.
Precision EdgeTM
Q1
/Q1
Q0
/Q0
IN
/IN
V
T
50
50
V
REF-AC
Q3
/Q3
Q2
/Q2
Q5
/Q5
Q4
/Q4
Q7
/Q7
Q6
/Q6
2
Precision EdgeTM
SY58031U
Micrel
M9999-022604
hbwhelp@micrel.com or (408) 955-1690
PACKAGE/ORDERING INFORMATION
Ordering Information
(1)
Package
Operating
Package
Part Number
Type
Range
Marking
SY58031UMI
MLF-32
Industrial
SY58031U
SY58031UMITR
(2)
MLF-32
Industrial
SY58031U
Notes:
1. Contact factory for die availability. Dice are guaranteed at
T
A
= 25
C,DC electricals only.
2. Tape and Reel.
Pin Number
Pin Name
Pin Function
3, 6
IN, /IN
Differential Signal Input: 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.
4
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.
2, 7, 17, 24
GND,
Ground. Exposed pad must be connected to a ground plane that is the same potential
Exposed Pad
as the ground pin.
1, 8, 9, 16
VCC
Positive Power Supply: Bypass with 0.1
F
0.01
F low ESR capacitors as close to the
18, 23, 25, 32
pins as possible.
31, 30, 29, 28, 27,
Q0, /Q0, Q1, /Q1,
CML Differential Output Pairs: Differential buffered output copy of the input
26, 22, 21, 20, 19,
Q2, /Q2, Q3, /Q3,
signal. The CML output swing is typically 400mV into 50
. Unused output pairs may be
15, 14, 13, 12,
Q4, /Q4, Q5, /Q5,
left floating with no impact on jitter. See "CML Output Termination" section.
11, 10
Q6, /Q6, Q7, /Q7
5
VREF-AC
Bias Reference Voltage: Equal to V
CC
1.2V (typical), and used for AC-coupled
applications. See "Input Interface Applications" section. When using V
REF-AC
, bypass
with 0.01
F capacitor to V
CC
. Maximum sink/source current is 0.5mA.
PIN DESCRIPTION
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
9 10 11 12 13 14 15 16
32 3130 29 28 27 26 25
VCC
GND
IN
VT
VREF_AC
/IN
GND
VCC
GND
VCC
Q3
/Q3
Q4
/Q4
VCC
GND
/Q1
Q1
/Q0
Q0
VCC
Q2
/Q2
VCC
Q6
/Q6
Q7
/Q7
VCC
/Q5
Q5
VCC
32-Pin MLFTM
3
Precision EdgeTM
SY58031U
Micrel
M9999-022604
hbwhelp@micrel.com or (408) 955-1690
Absolute Maximum Ratings
(1)
Power Supply Voltage (V
CC
) ...................... 0.5V to +4.0V
Input Voltage (V
IN
) ......................................... 0.5V to V
CC
Current (V
T
)
Source or sink current on V
T
pin ........................
100mA
Input Current (V
T
)
Source or sink current on IN, /IN ..........................
50mA
Current (V
REF
)
Source or sink current on V
REF-AC
(3) .......................
1.5mA
Lead Temperature Soldering, (10 sec.) .................... 265
C
Storage Temperature Range (T
S
) ........... 65
C to +150
C
Operating Ratings
(2)
Power Supply Voltage (V
CC
) ................. +2.375V to +3.60V
Ambient Temperature Range (T
A
) ............. 40
C to +85
C
Package Thermal Resistance
(4)
MLFTM (
JA
)
Still-Air ............................................................. 35
C/W
MLFTM (
JB
)
Junction-to-Board ............................................ 20
C/W
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
CC
Power Supply Voltage
2.5V nominal
2.375
2.5
2.625
V
3.3V nominal
3.0
3.3
3.6
V
I
CC
Power Supply Current
V
CC
= max. no lead. Includes current
265
330
mA
through 50
pull-ups.
V
IH
Input HIGH Voltage
IN1, /IN1, Note 6
V
CC
1.6
V
CC
V
V
IL
Input LOW Voltage
IN1, /IN1
0
V
IH
0.1
V
V
IN
Input Voltage Swing
IN1, /IN1, see Figure 1a.
0.1
1.7
V
V
DIFF_IN
Differential Input Voltage Swing
IN1, /IN1, see Figure 1b.
0.2
V
|IN0, /IN0|, |IN1, /IN1|
R
IN
In-to-V
T
Resistance
40
50
60
V
T IN
Max. In-to-V
T
(IN, /IN)
1.28
V
V
REF-AC
V
CC
1.3 V
CC
1.2 V
CC
1.1
V
DC ELECTRICAL CHARACTERISTICS
(5)
T
A
= 40
C to +85
C
V
CC
= 2.5V
5% or 3.3V
10%; R
L
= 100
across Q and /Q; 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
V
V
OUT
Output Voltage Swing
see Figure 1a.
325
400
mV
V
DIFF_OUT
Differential Voltage Swing
see Figure 1b.
650
800
mV
R
OUT
Output Source Impedance
40
50
60
Notes:
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.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. Due to the limited drive capability, use for input of the same package only.
4. Thermal performance assumes exposed pad is soldered (or equivalent) to the device's most negative potential (GND) on the PCB.
JB
uses 4-layer
JA
in still-air number unless otherwise stated.
5. The circuit is designed to meet the DC specifications shown in the above tables after thermal equilibrium has been established.
6. V
IH
(min) not lower than 1.2V.
CML DC ELECTRICAL CHARACTERISTICS
(5)
4
Precision EdgeTM
SY58031U
Micrel
M9999-022604
hbwhelp@micrel.com or (408) 955-1690
V
CC
= 2.5V
5% or 3.3V
10%; 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
f
MAX
Maximum Operating Frequency
V
OUT
200mV
Clock
5
GHz
t
pd
Propagation Delay
(IN-to-Q)
150
230
300
ps
t
pd tempco
Differential Propagation Delay
35
fs/
C
Temperature Coefficient
t
SKEW
Output-to-Output (Within Device)
Note 8
7
20
ps
Part-to-Part
Note 9
100
ps
t
JITTER
Clock
Cycle-to-Cycle
Note 10
1
ps
rms
Total Jitter (Clock)
Note 11
10
ps
p-p
Random Jitter (RJ)
Note 12
1
ps
rms
t
r
, t
f
Output Rise/Fall Time
20% to 80%, at full output swing
30
50
65
ps
Notes:
7.
High frequency AC electricals are guaranteed by design and characterization. All outputs loaded, V
IN
100mV.
8.
Output-to-output skew is measured between outputs under identical transitions.
9.
Part-to-part 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. Part-to-part skew includes variation in t
pd
.
10. 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.
11. 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.
12. Random jitter is measured with a K28.7 comma detect character pattern, measured at 1.25Gbps and 2.5Gbps.
AC ELECTRICAL CHARACTERISTICS
(7)
SINGLE-ENDED AND DIFFERENTIAL SWINGS
V
IN
,
V
OUT
400mV (Typ.)
Figure 1a. Single-Ended Voltage Swing
V
DIFF_IN
,
V
DIFF_OUT
800mV (Typ.)
Figure 1b. Differential Voltage Swing
TIMING DIAGRAM
/IN
IN
/Q
Q
t
pd
t
pd
V
IN
V
OUT
5
Precision EdgeTM
SY58031U
Micrel
M9999-022604
hbwhelp@micrel.com or (408) 955-1690
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
-60 -40 -20 0
20 40 60 80 100
SKEW (ps)
TEMPERATURE (
C)
Output-to-Output Skew
vs. Temperature
TYPICAL OPERATING CHARACTERISTICS
200MHz Output
Output Swing
(100mV/div
.)
TIME (600ps/div.)
5GHz Output
TIME (25ps/div.)
Output Swing
(100mV/div
.)
0
50
100
150
200
250
300
350
400
450
0
1000
2000
3000
4000
5000
6000
7000
AMPLITUDE (mV)
FREQUENCY (MHz)
Amplitude
vs. Frequency
V
IN
= 200mV
220
225
230
235
240
245
250
255
260
265
0
200
400
600
800
1000
PROPAGATION DELAY (ps)
INPUT SWING (mV)
Propagation Delay
vs. Input Swing
218
219
220
221
222
223
224
225
226
-60 -40 -20 0
20 40 60 80 100
PROPAGATION DELAY (ps)
TEMPERATURE (
C)
Propagation Delay
vs. Temperature
V
IN
= 400mV
V
CC
= 2.5V, GND = 0, V
IN
= 100mV, T
A
= 25
C, unless otherwise stated.
2GHz Output
TIME (100ps/div.)
Output Swing
(100mV/div
.)
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