SY58038U
Ultra-Precision, 8:1 MUX with Internal
Termination and 1:2 LVPECL Fanout Buffer
Precision Edge
®
General Description
The SY58038U is a low-jitter, low-skew, high-speed 8:1
multiplexer with a 1:2 differential fanout buffer optimized
for precision telecom and enterprise server distribution
applications. The SY58038U distributes clock frequencies
from DC to 3.5GHz, and data rates to 4.5Gpbs guaranteed
over temperature and voltage.
The SY58038U differential input includes Micrel’s unique,
3-pin input termination architecture that directly interfaces
to any differential signal (AC- or DC-coupled) as small as
100mV without any level shifting or termination resistor
networks in the signal path. The outputs are 800mV, 100K
compatible LVPECL with extremely fast rise/fall times
guaranteed to be less than 100ps.
The SY58038U features a patented isolation design that
significantly improves channel-to-channel crosstalk
performance.
The SY58038U operates from a 2.5V ±5% or 3.3V ±10%
supply and is guaranteed over the full industrial
temperature range of –40°C to +85°C. The SY58038U 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
•
Selects between 1 of 8 inputs, and provides two precise,
low-skew LVPECL output copies
•
Ultra-low jitter design:
−
72fs
rms
phase jitter (typical)
•
Guaranteed AC performance over temperature and
voltage:
−
DC to 4.5Gbps throughput
−
<500ps propagation delay IN-to-Q (V
IN
> 100mV)
−
<100ps t
r
/ t
f
time
−
<15ps skew (output-to-output)
•
Unique, patented, channel-to-channel isolation design
provides superior crosstalk performance
•
Unique, patented, input termination and V
T
pin accepts
DC- and AC-coupled inputs
(CML, PECL, LVDS)
•
800mV LVPECL output swing
•
Power supply 2.5V ±5% or 3.3V ±10%
•
–40°C to +85°C temperature range
•
Available in 44-pin (7mm × 7mm) QFN package
Applications
•
•
•
•
Data communication systems
All SONET/SDH data/clock applications
All Fibre Channel applications
All Gigabit Ethernet applications
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
March 26, 2015
Revision 3.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58038U
Functional Block Diagram
Truth Table
SEL2
L
L
L
L
H
H
H
H
SEL1
L
L
H
H
L
L
H
H
SEL0
L
H
L
H
L
H
L
H
Q
IN0
IN1
IN2
IN3
IN4
IN5
IN6
IN7
/Q
/IN0
/IN1
/IN2
/IN3
/IN4
/IN5
/IN6
/IN7
March 26, 2015
2
Revision 3.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58038U
Ordering Information
(1)
Part Number
SY58038UMY
SY58038UMY TR
Notes:
1. Contact factory for die availability. Die are guaranteed at T
A
= +25°C, DC electricals only.
2. Tape and reel.
(2)
Marking
SY58038U
SY58038U
Operating Range
–40°C to +85°C
–40°C to +85°C
Package
44-pin (7mm × 7mm) QFN
44-pin (7mm × 7mm) QFN
Pin Configuration
44-Pin (7mm × 7mm) QFN (QFN-44)
(Top View)
March 26, 2015
3
Revision 3.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58038U
Pin Description
Pin
Number
20, 18
16, 14
13, 11
9, 7
5, 3
1, 43
42, 40
38, 36
19,15
12, 8
4, 44
41, 37
17
10
2
39
21
22
35
24, 27, 29, 32
25, 26
30, 31
23, 28, 33
Pin
Name
IN0, /IN0
IN1, /IN1
IN2, /IN2
IN3, /IN3
IN4, /IN4
IN5,/IN5
IN6, /IN6
IN7, /IN7
VT0, VT1
VT2, VT3
VT4, VT5
VT6, VT7
VREF-AC0
VREF-AC1
VREF-AC2
VREF-AC3
SEL0
SEL1
SEL2
VCC
Q0,/Q0
Q1,/Q1
GND, ePad
Pin Function
Differential Inputs: These input pairs are the differential signal inputs to the device. Inputs accept
AC or DC-coupled signals as small as 100mV. Each pin of a pair internally terminates to a VT pin
through 50Ω. Note that these inputs will default to an indeterminate state if left open. Refer to the
Input Interface Applications
section for more details.
Input Termination Center-Tap: Each side of the differential input pair terminates to a VT pin. The
VT pins provide a center-tap to a termination network for maximum interface flexibility. Refer to the
Input Interface Applications
section for more details
Reference Voltage: This output biases to V
CC
– 1.2V. It is used when AC coupling the inputs (IN,
/IN). For AC-coupled applications, connect VREF-AC to the VT pin and bypass with a 0.01μF low-
ESR capacitor to
V
CC
or GND, depending on input type. Refer to the
Input Interface Applications
section for more details.
The single-ended TTL/CMOS-compatible inputs select the inputs to the multiplexer. Note that this
input is internally connected to a 25kΩ pull-up resistor and will default to a logic HIGH state if left
open.
Positive Power Supply. Bypass with 0.1μF//0.01μF low-ESR capacitors as close to each VCC pin.
Differential Outputs: These LVPECL output pairs are the outputs of the device. Unused output
pairs may be left open. Each output is designed to drive 800mV into 50Ω terminated to V
CC
– 2V
(or V
CC
– 1.2V, if AC-coupled).
Ground. GND and exposed pad (ePad) must both be connected to the most negative potential of
chip ground.
March 26, 2015
4
Revision 3.0
hbwhelp@micrel.com
or (408) 955-1690
Micrel, Inc.
SY58038U
Absolute Maximum Ratings
(3)
Power Supply Voltage (V
CC
).........................
−0.5V
to +4.0V
Input Voltage (V
IN
). ...........................................
−0.5V
to V
CC
LVPECL Output Current (I
OUT
)
Continuous ............................................................ 50mA
Surge .................................................................. 100mA
(6)
Termination Current
Source or Sink Current (on VT pin) .................. ±100mA
Lead Temperature (soldering, 10s) .......................... +260°C
Storage Temperature Range (T
S
) .............
−65°C
to +150°C
Operating Ratings
(4)
Power Supply
Voltage (V
CC
) ...... +2.375V to +2.625V or +3.0V to 3.6V
Ambient Temperature (T
A
) .......................... –40°C to +85°C
(5)
Package Thermal Resistance
QFN (θ
JA
)
Still Air ......................................................... 24°C/W
QFN (ψ
JB
)
Junction-to-Board ........................................ 12°C/W
DC Electrical Characteristics
(7)
T
A
= –40°C to +85°C, unless otherwise noted.
Symbol
V
CC
I
CC
R
IN
R
DIFF_IN
V
IH
V
IL
V
IN
V
DIFF_IN
V
T_IN
V
REF-AC
Notes:
3. Permanent device damage may occur if ratings in the
Absolute Maximum Ratings
section are exceeded. This is a stress rating only and functional
operation is not implied for 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.
4. The datasheet limits are not guaranteed if the device is operated beyond the operating ratings.
5. Package thermal resistance assumes exposed pad is soldered (or equivalent) to the device’s most negative potential on the PCB.
ψ
JB
uses 4-layer
θ
JA
in still-air number unless otherwise stated.
6. Due to the limited drive capability, use for input of the same package only.
7. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
8. V
IH
(minimum), not lower than 1.2V.
Parameter
Power Supply Voltage
Power Supply Current
Input Resistance (IN-to-V
T
)
Differential Input Resistance (IN-to-/IN)
Input HIGH Voltage (IN-to-/IN)
Input LOW Voltage (IN-to-/IN)
Input Voltage Swing (IN-to-/IN)
Differential Input Voltage Swing (IN-to-/IN)
IN-to-V
T
(IN-to-/IN)
Output Reference Voltage
Condition
V
CC
= 2.5V
V
CC
= 3.3V
No load, maximum V
CC
Min.
2.375
3.0
Typ.
2.5
3.3
120
Max.
2.625
3.6
170
60
120
V
CC
V
IN
−
0.1
1.7
Units
V
mA
Ω
Ω
V
V
V
V
40
80
Note 8
V
CC
−
1.6
0
See
Figure 1
See
Figure 2
0.1
0.2
50
100
1.28
V
CC
−
1.3
V
CC
−
1.2
V
CC
−
1.1
V
V
March 26, 2015
5
Revision 3.0
hbwhelp@micrel.com
or (408) 955-1690
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