Micrel, IIIIInc.
ULTRA PRECISION 8:1 MUX
WITH INTERNAL TERMINATION
AND 1:2 CML FANOUT BUFFER
Precision Edge
®
SY58037U
Precision Edge
®
SY58037U
FEATURES
Selects between 1 of 8 inputs, and provides two
precision, low skew CML output copies
Guaranteed AC performance over temperature and
voltage:
• DC to 5Gbps throughput
• <450ps propagation delay IN-to-Q (V
IN
≥
300mV)
• <70ps t
r
/ t
f
time
• <15ps skew (output-to-output)
Unique, patent-pending, channel-to-channel
isolation design provides superior crosstalk
performance
Ultra-low jitter design:
• <1ps
RMS
random jitter
• <10ps
PP
deterministic jitter
• <10ps
PP
total jitter (clock)
• <0.7ps
RMS
crosstalk-induced jitter
Unique, patent-pending, input termination and VT
pin accepts DC- and AC-coupled inputs (CML, PECL,
LVDS)
400mV CML output swing
50
Ω
source terminated outputs minimize round-trip
reflections
Power supply 2.5V
±
5% or 3.3V
±
10%
–40
°
C to +85
°
C temperature range
Available in 44-pin (7mm x 7mm) QFN package
Precision Edge
®
DESCRIPTION
The SY58037U 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 SY58037U distributes clock frequencies
from DC to 4GHz and data rates to 5Gpbs guaranteed over
temperature and voltage.
The SY58037U 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 (200mVpp) without any level shifting or termination
resistor networks in the signal path. The outputs are 50Ω
source-terminated CML with extremely fast rise/fall time
guaranteed to be less than 70ps.
The SY58037U features a patent-pending isolation design
that significantly improves channel-to-channel crosstalk
performance.
The SY58037U 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 SY58037U is part of Micrel’s
high-speed, Precision Edge
®
product line.
Datasheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
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.
M9999-010708
hbwhelp@micrel.com or (408) 955-1690
Rev.: E
Amendment: /0
1
Issue Date: January 2008
Micrel, Inc.
Precision Edge
®
SY58037U
FUNCTIONAL BLOCK DIAGRAM
IN0
50Ω
VT0
50Ω
/IN0
VREF-AC0
IN1
50Ω
VT1
50Ω
/IN1
IN2
50Ω
VT2
50Ω
8:1 MUX
0
1
1:2 Fanout
/IN2
VREF-AC1
IN3
50Ω
VT3
50Ω
2
3
4
MUX
Q0
/Q0
Q1
/Q1
S2
S1
/IN3
IN4
50Ω
VT4
50Ω
5
6
7
/IN4
VREF-AC2
IN5
50Ω
VT5
50Ω
S0
/IN5
IN6
50Ω
VT6
50Ω
/IN6
VREF-AC3
IN7
50Ω
VT7
50Ω
/IN7
SEL0 (CMOS/TTL)
SEL1 (CMOS/TTL)
SEL3 (CMOS/TTL)
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
M9999-010707
hbwhelp@micrel.com or (408) 955-1690
2
Micrel
Precision Edge®
SY58037U
PACKAGE/ORDERING INFORMATION
VT5
/IN5
IN6
VT6
/IN6
VREF-AC3
IN7
VT7
/IN7
SEL2
NV
Ordering Information
(1)
Part Number
GND
VCC
/Q1
Q1
VCC
GND
VCC
/Q0
Q0
VCC
GND
44 43 42 41 40 39 38 37 36 35 34
Package
Type
QFN-44
QFN-44
Operating
Range
Industrial
Industrial
Package
Marking
SY58037U with
Pb-Free bar-line indicator
SY58037U with
Pb-Free bar-line indicator
Lead
Finish
Pb-Free
Matte-Sn
Pb-Free
Matte-Sn
IN5
VREF-AC2
/IN4
VT4
IN4
NC
/IN3
VT3
IN3
VREF-AC1
/IN2
33
1
2
32
3
31
4
30
5
29
6
28
7
27
8
26
9
25
24
10
23
11
12 13 14 15 16 17 18 19 20 21 22
SY58037UMY
SY58037UMYTR
(2)
Notes:
1. Contact factory for die availability. Dice are guaranteed at T
A
= 25°C, DC electricals only.
2. Tape and Reel.
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,
Exposed Pad
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.
Please refer to the
“Input
Interface Applications” section for more details.
VT2
IN2
/IN1
VT1
IN1
VREF-AC0
/IN0
VT0
IN0
SEL0
SEL1
44-Pin QFN
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.
See
“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
. See
“Input
Interface Applications” section for more details.
The 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 0.1µF0.01µF low ESR capacitors as close to each VCC
pin.
Differential Outputs: These CML output pairs are the outputs of the device. Please refer to
the truth table below for details. Unused output pairs may be left open. Each output is designed
to drive 400mV into 100Ω across each output pair.
Ground. GND and exposed pad must both be connected to the most negative potential of chip
ground.
3
Micrel
Precision Edge®
SY58037U
Absolute Maximum Ratings
(1)
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
Termination Current
(3)
Source or sink current on VT pin ........................
±100mA
Lead Temperature (soldering, 20 sec.) ..................... 260°C
Storage Temperature Range (T
S
) ...........
–65°C
to +150°C
Operating Ratings
(2)
Power Supply Voltage (V
CC
) ............... +2.375V to +2.625V
............................................................ +3.0V to +3.6V
Ambient Temperature Range (T
A
) .............
–40°C
to +85°C
Package Thermal Resistance
(4)
QFN (θ
JA
)
Still-Air ............................................................. 24°C/W
QFN (ψ
JB
)
Junction-to-board ............................................ 12°C/W
DC ELECTRICAL CHARACTERISTICS
(5)
T
A
=
–40°C
to +85°C, unless otherwise stated.
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:
1. 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.
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. 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.
5. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
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, max. V
CC
.
Min
2.375
3.0
40
80
V
CC
–1.2
0
Typ
2.5
3.3
145
50
100
Max
2.625
3.6
200
60
120
V
CC
V
IH
–0.1
1.7
Units
V
V
mA
Ω
Ω
V
V
V
V
See Figure 1a.
See Figure 1b.
0.1
0.2
1.28
V
CC
–1.3
V
CC
–1.2
V
CC
–1.1
V
V
4
Micrel
Precision Edge®
SY58037U
CML OUTPUT DC ELECTRICAL CHARACTERISTICS
(7)
V
CC
= 2.5V
±5%
or 3.3V
±10%;
T
A
= –40°C to +85°C; R
L
= 100Ω across each output pair, unless otherwise stated.
Symbol
V
OH
V
OUT
V
DIFF_OUT
R
OUT
Parameter
Output HIGH Voltage
Q, /Q
Output Differential Swing
Q, /Q
Differential Output Voltage Swing
Q, /Q
Output Source Impedance
See Figure 1a.
See Figure 1b.
Condition
Min
Typ
Max
V
CC
Units
V
mV
mV
60
Ω
V
CC
–0.040 V
CC
–0.010
325
650
40
400
800
50
LVTTL/CMOS DC ELECTRICAL CHARACTERISTICS
(7)
V
CC
= 2.5V
±5%
or 3.3V
±10%;
T
A
= –40°C to +85°C, unless otherwise stated.
Symbol
V
IH
V
IL
I
IH
I
IL
Note:
7. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
Parameter
Input HIGH Voltage
Input LOW Voltage
Input HIGH Current
Input LOW Current
Condition
Min
2.0
–125
–300
Typ
Max
V
CC
0.8
30
Units
V
V
μA
μA
5