SY58031U
Ultra-Precision 1:8 CML Fanout Buffer
with Internal I/O Termination
General Description
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 only 75fs
RMS
phase jitter. It can
process clock signals as fast as 6GHz.
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 50Ω loads and
provide an extremely fast rise/fall time guaranteed to be
less than 60ps.
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 Edge product line.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com.
Precision Edge
®
Features
•
Precision 1:8, 400mV CML fanout buffer
•
Guaranteed AC performance over temperature and
voltage:
−
Clock frequency range: DC to >6GHz
−
<60ps t
r
/t
f
time
−
<270ps t
pd
−
<20ps output-to-output skew
•
Low-jitter performance:
−
75fs
RMS
phase jitter (typ.)
•
50Ω
source-terminated CML outputs
•
400mV CML output swing into
50Ω
load
•
Fully differential I/O
•
Accepts an input signal as low as 100mV
•
Unique, patent-pending input termination and VT pin
accepts DC-coupled and AC-couple differential inputs
(LVPECL, LVDS, and CML)
•
Power supply 2.5V ±5% or 3.3V ±10%
•
Industrial temperature range: –40°C to +85°C
•
Available in 32-pin, 5mm × 5mm QFN package
Block Diagram
Q0
/Q0
Q1
/Q1
Q2
/Q2
IN
50Ω
V
T
/IN
V
REF-AC
50Ω
Applications
•
•
•
•
All SONET and GigE clock distribution
All Fibre Channel clock and data distribution
Network routing engine timing distribution
High-end, low-skew multiprocessor synchronous clock
distribution
Q3
/Q3
Q4
/Q4
Q5
/Q5
Q6
/Q6
Q7
/Q7
United States Patent No. RE44,134
Precision Edge is a registered trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive •
San
Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
October 1, 2013
Revision 5.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58031U
Ordering Information
Part Number
(1)
Package Type
QFN-32
(2)
Operating
Range
Industrial
Industrial
Package Marking
SY58031U with Pb-free bar-line indicator
SY58031U with Pb-free bar-line indicator
Lead Finish
Pb-Free NiPdAu
Pb-Free NiPdAu
SY58031UMG
SY58031UMGTR
Note:
QFN-32
1. Contact factory for die availability. Dice are guaranteed at T
A
= 25°C, DC electricals only.
2. Tape and Reel.
October 1, 2013
2
Revision 5.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58031U
Pin Configuration
32-Pin
QFN
Pin Description
Pin Number
3, 6
Pin Name
IN, /IN
Pin Function
Differential signal input:
Each pin of this pair internally terminates with 50Ω to the VT pin.
Note that this input will default to an indeterminate state if left open. See Input Interface
Applications section.
Input termination center-tap: Each input terminates to this pin. The VT pin provides a center-
tap for each input (IN, /IN) to the termination network for maximum interface flexibility. See
Input Interface Applications section.
Ground. Exposed pad must be connected to a ground plane that is the same potential as the
ground pin.
Positive power supply: Bypass with 0.1μF/0.01μF
low ESR capacitors as close to the pins as
possible
CML differential output pairs: Differential buffered output copy of the input signal. The CML
output swing is typically 400mV into 50Ω. Unused output pairs may be left floating with no
impact on jitter. See CML Output Termination section
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 0.01μF capacitor
to V
CC
. Maximum sink/source current is 0.5mA.
4
2, 7, 17, 24
1, 8, 9, 16
18, 23, 25, 32
31, 30, 29, 28,
27, 26, 22, 21
20, 19, 15, 14
13, 12, 11, 10
5
VT
GND,
Exposed Pad
VCC
Q0, /Q0, Q1, /Q1
Q2, /Q2. Q3, /Q3
Q4, /Q4, Q5, /Q5
Q6, /Q6, Q7, /Q7
VREF-AC
October 1, 2013
3
Revision 5.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58031U
Absolute Maximum Ratings
(3)
Power Supply Voltage (VCC) ....................... –0.5V to +4.0V
Input Voltage (VIN) ......................................... –0.5V to VCC
Current (VT)
Source or sink current on VT pin.......................... ±100mA
Input Current (VT)
Source or sink current on IN, /IN ............................ ±50mA
Current (VREF)
(5)
Source or sink current on VREF-AC .................. ±1.5mA
Lead Temperature (soldering, 20s) ............................ 260°C
Storage Temperature (Ts)......................... –65°C to +150°C
Operating Ratings
(4)
Power Supply Voltage (V
CC
) .................... +2.375V to +3.6V
Ambient Temperature (T
A
) .......................... –40°C to +85°C
(6)
Junction Thermal Resistance
QFN (θ
JA
), Still-Air .............................................. 35°C/W
QFN (ψ
JB
), Junction-to-Board ............................ 20°C/W
DC
Electrical Characteristics
(7)
T
A
= –40°C to +85°C.
Symbol
V
CC
I
CC
V
IH
V
IL
V
IN
V
DIFF_IN
R
IN
V
T IN
V
REF-AC
Parameter
Power supply voltage
Power supply current
Input HIGH voltage
Input LOW voltage
Input voltage swing
Differential input voltage swing
[IN0, /IN0], [IN1, /IN1]
In-to-V
T
resistance
Max. In-to-V
T
(IN, /IN)
V
CC
-1.3
V
CC
-1.2
Condition
2.5V nominal
3.3V nominal
VCC = max., no lead. Includes current
through 50Ω pull-ups.
IN1, /IN1,
Note 8
IN1, /IN1
IN1, /IN1, see
Figure 1.
IN1, /IN1, see
Figure 2.
V
CC
-1.6
0
0.1
0.2
40
50
60
1.28
V
CC
-1.1
Min.
2.375
3.0
Typ.
2.5
3.3
265
Max.
2.625
3.6
330
V
CC
V
IH
-0.1
1.7
Units
V
mA
V
V
V
V
Ω
V
V
October 1, 2013
4
Revision 5.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58031U
CML DC Electrical Characteristics
(7)
V
CC
= 2.5V ±5% or 3.3V ±10%; R
L
= 100Ω across Q and /Q; T
A
= –40°C to +85°C, unless otherwise stated.
Symbol
V
OH
V
OUT
V
DIFF_OUT
R
OUT
Notes:
3. Exceeding the absolute maximum ratings may damage the device.
4. The datasheet ratings are not guaranteed if the device is operated beyond the operating ratings.
5. Due to the limited drive capability, use for input of the same package only.
6. Thermal performance assumes exposed pad is soldered (or equivalent) to the device’s most negative potential (GND) on the PCB.
ψ
JB
uses 4-layer
θ
JA
in still-air number unless otherwise stated.
7. The device is not guaranteed to function outside its operating ratings.
8. V
IH
(min.) not lower than 1.2V.
Parameter
Output HIGH voltage
Output LOW voltage
Differential voltage swing
Output source impedance
Condition
Min.
V
CC
-
0.02
Typ.
Max.
V
CC
Units
V
mV
mV
See
Figure 1.
See
Figure 2.
325
650
40
400
800
50
60
Ω
AC Electrical Characteristics
(9)
VCC = 2.5V ±5% or 3.3V ±10%; RL = 100Ω across each output pair or equivalent; T
A
= –40°C to +85°C, unless otherwise stated.
Symbol
f
MAX
t
pd
t
pd tempco
t
SKEW
t
JITTER
t
r
/t
f
Notes:
9. High frequency AC electricals are guaranteed by design and characterization. All outputs loaded, V
IN
≥100mV.
10. Output-to-output skew is measured between outputs under identical transitions.
11. Part-to-part skew is defined for two parts with identical power supply voltages at the same temperature with no skew of the edges at the respective
inputs. Part-to-part skew includes variation in t
pd
.
Parameter
Maximum operating frequency
Propagation delay (IN-to-Q)
Differential propagation delay
temperature coefficient
Output-to-output (within device)
Part-to-part
RMS phase jitter
Output rise/fall time
Condition
V
OUT
≥200mV
clock
Min.
6
120
Typ.
230
35
Max.
270
Units
GHz
ps
fs/°C
Note 10
Note 11
Output: 622MHz
Integration range 12kHz – 20MHz
20% to 80% at full output swing.
20
7
20
100
ps
ps
ps
75
45
60
ps
October 1, 2013
5
Revision 5.0
hbwhelp@micrel.com
or (408) 955-1690
京公网安备 11010802033920号
EEWORLD
