Micrel, Inc.
6GHz, 1:6 CML FANOUT BUFFER
WITH 2:1 MUX INPUT AND
INTERNAL I/O TERMINATION
Precision Edge
SY58034U
Precision Edge®
SY58034U
®
FEATURES
Provides six ultra-low skew copies of the selected
input
2:1 MUX input included for clock switchover
applications
Guaranteed AC performance over temperature and
voltage:
•
Clock frequency range: DC to > 6GHz
•
<290ps IN-to-OUT t
pd
•
<60ps t
r
/ t
f
times
•
<20ps skew (output-to-output)
Unique input isolation design minimizes crosstalk
Ultra low-jitter design:
•
60fs RMS phase jitter
•
<0.7ps
RMS
crosstalk-induced jitter
Low supply voltage operation: 2.5V and 3.3V
Unique input termination and VT pin accepts DC-
coupled and AC-coupled inputs (CML, PECL, LVDS)
Internal
50Ω
output source termination
400mV CML output swing
–40°C to +85°C temperature range
Available in 32-pin (5mm x 5mm) QFN package
Precision Edge
®
DESCRIPTION
The SY58034U is a 2.5V/3.3V precision, high-speed 1:6
fanout buffer capable of handling clocks up to 6GHz. A
differential 2:1 MUX input is included for redundant clock
switchover applications.
The differential input includes Micrel’s unique, 3-pin input
termination architecture that allows the device to interface
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 50½ source
terminated CML, with extremely fast rise/fall times
guaranteed to be less than 60ps.
The SY58034U operates from a 2.5V ±5% supply or a
3.3V ±10% supply and is guaranteed over the full industrial
temperature range of –40°C to +85°C. For applications that
require LVPECL outputs, consider the SY58035U or
SY58036U Multiplexers. The SY58034U is part of Micrel’s
high-speed, Precision Edge
®
product line.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
APPLICATIONS
Redundant clock distribution
All SONET/SDH clock distribution
All Fibre Channel distribution
All Gigabit Ethernet clock distribution
FUNCTIONAL BLOCK DIAGRAM
1:6 Fanout
Q0
/Q0
IN0
50Ω
V
T0
50Ω
/IN0
V
REF-AC0
IN1
50Ω
V
T1
50Ω
/IN1
V
REF-AC1
SEL
(TTL/CMOS)
1
S
0
2:1 MUX
Q1
/Q1
Q2
MUX
/Q2
Q3
/Q3
Q4
/Q4
Q5
United States Patent No. RE44,134
Precision Edge is a registered trademark of Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
/Q5
1
Rev.: E
Amendment: /0
Issue Date: August 2007
Micrel, Inc.
Precision Edge®
SY58034U
PACKAGE/ORDERING INFORMATION
GND
SEL
VCC
Q0
/Q0
Q1
/Q1
VCC
Ordering Information
(1)
GND
VCC
Q2
/Q2
Q3
/Q3
VCC
GND
IN0
VT0
VREF-AC0
/IN0
IN1
VT1
VREF-AC1
/IN1
32 31 30 29 28 27 26 25
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
24
23
22
21
20
19
18
17
Part Number
SY58034UMG
SY58034UMGTR
(2)
Notes:
Package Operating
Type
Range
QFN-32
QFN-32
Industrial
Industrial
Package
Marking
Lead
Finish
SY58034U with
NiPdAu
Pb-free bar-line indicator Pb-Free
SY58034U with
NiPdAu
Pb-free bar-line indicator Pb-Free
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
1, 4
5, 8
Pin Name
IN0, /IN0
IN1, /IN1
Pin Function
Differential Input: These input pairs are the differential signal inputs to the device. These
inputs accept AC- or DC-coupled signals as small as 100mV. Each pin of a pair internally
terminates to a VT pin through 50½. Note that these inputs will default to an indeterminate
state if left open. Please 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 VT0 and VT1 pins provide a center-tap to a termination network for maximum
interface flexibility. See “Input Interface Applications” section for more details.
This single-ended TTL/CMOS-compatible input selects the inputs to the multiplexer. Note
that this input is internally connected to a 25k½ pull-up resistor and will default to a logic
HIGH state if left open. The MUX select switchover function is asynchronous.
No connect.
Positive Power Supply: Bypass with 0.1µF™™ 0.01µF low ESR capacitors and place as
close to the VCC pins as possible.
Differential Outputs: These CML output pairs are low skew output copies of the selected
input. The output stage is optimized to deliver a 400mV swing (single-ended) into 50½.
Each output includes a 50½ source-termination resistor, thus minimizing any return
reflections. Unused output pins may be left floating. Please refer to the “Truth Table”
for details.
Ground. Ground pin and exposed pad must be connected to the same ground plane.
Reference Voltage: These output biases to V
CC
–1.2V. It is used for AC-coupling inputs
(IN, /IN). Connect V
REF-AC
directly to the VT pin. Bypass with 0.01µF low ESR capacitor to
V
CC
. See “Input Interface Applications” section. Maximum sink/source current is ±1.5mA.
Due to the limited capability, the VREF-AC pin is only intended to drive its respective VT
pin.
2, 6
31
10
11, 16, 18,
23, 25, 30
29, 28
27, 26
22, 21
20, 19
15, 14
13, 12
9, 17, 24, 32
3, 7
TRUTH TABLE
SEL
0
1
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
GND
NC
VCC
/Q5
Q5
/Q4
Q4
VCC
32-Pin QFN
VT0, VT1
SEL
NC
VCC
Q0, /Q0,
Q1, /Q1,
Q2, /Q2,
Q3, /Q3,
Q4, /Q4,
Q5, /Q5
GND,
Exposed Pad
VREF-AC0,
VREF-AC1
IN0 Input Selected
IN1 Input Selected
2
Micrel, Inc.
Precision Edge®
SY58034U
Absolute Maximum Ratings
(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
Termination Current
Source or sink current on VT pin ........................ ±100mA
Input Current
Source or sink current on IN, /IN pin .................... ±50mA
Source or sink current on VREF-AC pin ................. ±2mA
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
(3)
QFN (θ
JA
)
Still-Air ............................................................. 35°C/W
QFN (ψ
JB
)
Junction-to-Board ............................................ 16°C/W
DC ELECTRICAL CHARACTERISTICS
(4)
T
A
= –40°C to 85°C, unless otherwise stated.
Symbol
V
CC
I
CC
R
DIFF_IN
R
IN
V
IH
V
IL
V
IN
V
DIFF_IN
V
T
IN
V
REF-AC
Notes:
1. Permanent device damage may occur if the measurements in the “Absolute Maximum Ratings” section 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. Thermal performance assumes exposed pad is soldered (or equivalent) to the device’s most negative potential on the PCB.
Ψ
JB
and
θ
JA
are
determined for a 4-layer board in a still air, unless otherwise stated.
4. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
5. V
IH
(min) not lower than 1.2V.
Parameter
Power Supply Voltage
Power Supply Current
Differential Input Resistance
|IN–/IN|
Input Resistance (IN-to-VT)
Input HIGH Voltage (IN, /IN)
Input LOW Voltage (IN, /IN)
Input Voltage Swing (IN, /IN)
Differential Input Voltage Swing
|IN, /IN|
IN to V
T
(IN, /IN)
Reference Voltage
Condition
Min
2.375
3.0
Typ
2.5
3.3
245
100
50
Max
2.625
3.6
320
110
55
V
CC
V
IH
–0.1
1.7
Units
V
V
mA
½
½
V
V
V
V
No load, max. V
CC
90
45
Note 5
See Figure 1a.
See Figure 1b.
V
CC
–1.6
0
0.1
0.2
1.28
V
CC
–1.3 V
CC
–1.2 V
CC
–1.1
V
V
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
3
Micrel, Inc.
Precision Edge®
SY58034U
CML OUTPUT DC ELECTRICAL CHARACTERISTICS
(6)
V
CC
= 2.5V ±5% or 3.3V ±10%; T
A
= -40°C to 85°C; R
L
= 100½ across each output pair or equivalent, unless otherwise stated.
Symbol
Parameter
Condition
Min
Typ
Max
V
OH
V
OUT
V
DIFF_OUT
R
OUT
Output HIGH Voltage
Output Voltage Swing
Differential Output Voltage Swing
Output Source Impedance
R
L
= 50½ to V
CC
See Figure 1a.
See Figure 1b.
V
CC
–0.020
325
650
40
400
800
50
60
V
CC
Units
V
mV
mV
½
LVTTL/CMOS DC ELECTRICAL CHARACTERISTICS
(6)
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:
6. 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
Typ
Max
Units
V
0.8
–125
–300
40
V
μA
μA
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
4
Micrel, Inc.
Precision Edge®
SY58034U
AC ELECTRICAL CHARACTERISTICS
(7)
V
CC
= 2.5V ±5% or 3.3V ±10%; T
A
= –40°C to 85°C, R
L
= 100½ across each output pair, or equivalent, unless otherwise stated.
Symbol
f
MAX
t
pd
Parameter
Maximum Operating Frequency
Differential Propagation Delay
(IN0 or IN1-to-Q)
(SEL-to-Q)
∆t
pd
Tempco
t
SKEW
t
JITTER
RMS Phase Jitter
Adjacent Channel
Crosstalk-Induced Jitter
t
r
, t
f
Notes:
7. High frequency AC electricals are guaranteed by design and characterization.
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.
10. Crosstalk is measured at the output while applying two similar clock frequencies that are asynchronous with respect to each other at the inputs.
Condition
Clock V
OUT
ž
200mV
Min
6
140
100
Typ
7.5
220
200
65
Max
Units
GHz
290
400
ps
ps
fs/°C
Differential Propagation Delay
Temperature Coefficient
Output-to-Output
Part-to-Part
Note 8
Note 9
Output = 622MHz
Integration range: 12kHz - 20MHz
Note 10
Full swing, 20% to 80%
20
20
100
60
ps
ps
fs
0.7
60
ps
RMS
ps
Output Rise/Fall Time
SINGLE-ENDED AND DIFFERENTIAL SWINGS
V
IN
,
V
OUT
400mV (Typ.)
V
DIFF_IN
,
V
DIFF_OUT
800mV (Typ.)
Figure 1a. Single-Ended Voltage Swing
Figure 1b. Differential Voltage Swing
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
5
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