1:8 CML & LVPECL Fanout Buffer
SY58031/2/3U Evaluation Board
General Description
The SY58031U, SY58032U and SY58033U
evaluation boards are designed for convenient setup
and quick evaluation of the respective devices. The
boards are optimized to interface directly to a 50Ω
oscilloscope.
For best AC performance, the boards are configured
with AC-Coupled Input and DC-Coupled Output. For
applications that require AC-coupled output
configuration, step-by-step instructions for modifying
the board are included.
All data sheets and support documentation can be
found on Micrel’s web site at
www.micrel.com.
Features
•
SY58031U, SY58032U, SY58033U
•
+2.5V or +3.3V power supply
•
AC-Coupled Input and DC-Coupled Output
configuration for performance
•
Fully assembled and tested
•
Outputs can be reconfigured for AC-coupled
output operation
Related Documentation
•
SY58031U, 3.3V/5V Ultra-Precision 1:8 CML
Fanout Buffer w/Internal Termination Data sheet
•
SY58032U, 3.3V/5V Ultra-Precision 1:8 LVPECL
Fanout Buffer w/Internal Termination Data sheet
•
SY58033U, 3.3V/5V Ultra-Precision 1:8 400mV
LVPECL Fanout Buffer w/Internal Termination
Data sheets
____________________________________________________________________________________
Evaluation Board
SY58031
SY58032/3
August 2004
M9999-080304
hbwhelp@micrel.com
or (408) 955-1690
Micrel
SY58031/2/3 Evaluation Board
Evaluation Board Description
The SY58031U is a CML evaluation board and the
SY58032U and SY58033U are LVPECL and 400mV
LVPECL evaluation boards sharing the same design.
The default configuration for these boards is AC-
coupled Input and DC-coupled output. The output can
be reconfigured for AC-coupled output operation;
therefore, the choice between two configurations
offers flexibility for specific applications.
DC-Coupled Output
The DC-coupled configuration is an industry standard
configuration suited for enhanced AC performance.
The CML SY58031U requires a single power supply
of either 2.5V +5% or 3.3V +10% and offers the most
flexibility in interfacing to a variety of signal sources.
Since LVPECL is referenced to V
CC
, the standard
PECL termination is 50Ω to V
CC
–2V. Split supply is an
easy method to interface to a 50Ω (to ground) scope.
Therefore, a 3.3V supply will be split into +2V and
–1.3V, and a +2.5V supply will be split into +2V and
–0.5V. The +2V offset in the two-power supply
configuration provides the correct termination for the
device by setting the GND potential on the board to
2V below the V
CC
supply. The V
EE
voltage is then set
to –0.5V for 2.5V operation or –1.3V for 3.3V to
ensure proper V
CC
to V
EE
voltage difference.
Any-Input Interface
The unique internal input termination sets the input
common mode voltage. This enables the input to
interface with any differential signal over the supply
voltage without modifying the evaluation board
August 2004
2
M9999-080302
hbwhelp@micrel.com
or (408) 955-1690
Micrel
SY58031/2/3 Evaluation Board
Evaluation Board
SY58031U CML Evaluation Board
I/O
AC-In/DC-Out
AC-In/DC-Out
AC-In/AC-Out
AC-In/AC-Out
Power
Supply
2.5V
3.3V
2.5V
3.3V
V
CC
+2V
+2V
+2.5V
+3.3V
GND
0
0
0
0
V
EE
–0.5
–1.3
0
0
C3-C8
0Ω
0Ω
0.1µF
0.1µF
Table 1. SY58031U Configuration
Note: The default configuration is AC-In/DC-Out.
August 2004
3
M9999-080302
hbwhelp@micrel.com
or (408) 955-1690
Micrel
SY58031/2/3 Evaluation Board
SY58032/3U LVPECL Evaluation Board
I/O
AC-In/DC-Out
AC-In/DC-Out
AC-In/AC-Out
AC-In/AC-Out
Power
Supply
2.5V
3.3V
2.5V
3.3V
V
CC
+2V
+2V
+2.5V
+3.3V
GND
0
0
0
0
V
EE
–0.5
–1.3
0
0
R1-R6
None
None
50Ω
100Ω
C6-C7, C10-C11,
C16-C17
0Ω
0Ω
0.1µF
0.1µF
Table 2. SY58032/3U Configuration
Note: The default configuration is AC-In/DC-Out.
August 2004
4
M9999-080302
hbwhelp@micrel.com
or (408) 955-1690
Micrel
SY58031/2/3 Evaluation Board
DC-Coupled Evaluation Board Setup
The follow steps describe the procedure for setting up
the evaluation board:
SY58031U
Set the voltage setting for the DC supply to either
2.5V or 3.3V depending on the application and turn
off the supply. Connect the GND terminal to the
negative side of a DC power supply. This is the 0V
ground potential. Connect the V
CC
terminal to the
positive side of a DC power supply.
SY58032/3U
1. Signal Generator: Using a differential signal
source, set the amplitude of each side of the
differential pair to 400mV (800mV measured
differentially). Set the offset to a positive
value, the value of the offset is not critical,
since the AC-coupled inputs will be
automatically biased. Turn off or disable the
outputs of the signal source.
2. I/O Cable Interface: Using equal length 50Ω
impedance coaxial cables connect the signal
source to the inputs on the evaluation board.
Using equal length 50Ω impedance coaxial
cables connect the outputs of the evaluation
board to the oscilloscope or other
measurement device that has an internal
50Ω termination. Unequal length cables are
not recommended since they introduce duty
cycle distortion and unwanted signal delays.
3. Connect the trigger input of the scope to the
trigger output of the signal generator.
4. Enable the signal source and monitor the
outputs.
For 2.5V operation:
•
V
CC
= 2.0V
•
V
EE
= –0.5V
•
GND = 0V
For 3.3V operation:
•
V
CC
= 2.0V
•
V
EE
= –1.3V
•
GND = 0V
August 2004
5
M9999-080302
hbwhelp@micrel.com
or (408) 955-1690
瑞萨MCU/MPU
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