GENNUM CORPORATION P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3
Tel. +1 (905) 632-2996 Fax. +1 (905) 632-5946 E-mail: info@gennum.com
www.gennum.com
Revision Date: April 2000
Document No. 521 - 68 - 04
DATA SHEET
G
S
9
028
FEATURES
SMPTE 259M compliant
two complementary outputs, adjustable from 50 to
1000mVp-p into 75
loads
operational from DC to 622Mb/s
nominal 470ps rise and fall times
< 7% output amplitude control
45% system power reduction over the GS9008
no external pulldown resistors required
input hysteresis
operational down to 80mV input amplitude
operates from a single +5 or -5 volt supply
8 pin SOIC
APPLICATIONS
4sc, 4:2:2, and 4:4:4:4 serial digital video interfaces from
143Mb/s to 540Mb/s; general purpose high speed cable
driver applications.
DESCRIPTION
The GS9028 is a second generation bipolar integrated
circuit designed to drive two 75
co-axial cables.
The GS9028 features two complementary outputs whose
amplitude is controlled within 7%. The output signal levels
are also adjustable from as low as 50mV to as high as
1000mV with little change in other performance parameters.
The output amplitude of the output stage is varied by
adjusting the R
SET
resistor value.
The GS9028 consumes 45% less system power than the
GS9008 and does not require external pulldown resistors
resulting in a smaller PCB footprint. Operational with input
amplitudes as low as 80mV, the GS9028 is a robust serial
interface device.
The GS9028 is packaged in an 8 pin SOIC and operates
from a single +5 or -5 volt supply.
BLOCK DIAGRAM
ORDERING INFORMATION
PART NUMBER
PACKAGE
TEMPERATURE
GS9028-CKA
8 pin SOIC
0C to 70C
GS9028-CTA
8 pin SOIC Tape
0C to 70C
SDO
R
SET
SDO
SDI
SDI
BANDGAP REFERENCE AND BIASING CIRCUIT
OUTPUT STAGE
& RISE/FALL TIME
CONTROL CIRCUIT
INPUT
DIFFERENTIAL
PAIR WITH
HYSTERESIS
GENLINX
TM
II
GS9028 Cable Driver
with Two Adjustable Outputs
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S
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ABSOLUTE MAXIMUM RATINGS
T
A
= 25C unless otherwise specified
PARAMETER
VALUE
Supply Voltage
5.5V
Input Voltage Range (any input)
-0.3 to (V
CC
+0.3)V
Operating Temperature Range
0 to 70C
Storage Temperature
-65 to 150C
Lead Temperature (soldering, 10 sec)
260C
DC ELECTRICAL CHARACTERISTICS
V
CC
= 5V, T
A
= 0C to 70C unless otherwise shown. Specifications assume 800mV output amplitude levels into end terminated 75
transmission lines.
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
TEST
LEVEL
Supply Voltage
V
CC
4.75
5.00
5.25
V
1
System Power
Consumption
P
D
Driving two 75
cables
-
165
195
mW
3
Supply Current
S
-
33
39
mA
3
Common Mode Input
Voltage Range
V
CM,IN
2.4+(V
DIFF
/2)
-
V
CC
-(V
DIFF
/2)
V
2
Differential Input
V
DIFF
80
-
1000
mV
2
Common Mode
Output Voltage Range
V
CM,OUT
-
V
CC
-V
OUT
-
V
2
Differential Output
V
OUT
R
SET
= 59
750
800
850
mV
1
Input Hysteresis
10
-
-
mV
2
AC ELECTRICAL CHARACTERISTICS
V
CC
= 5V, T
A
= 0C to 70C unless otherwise shown. Specifications assume 800mV output amplitude levels into end terminated 75
transmission lines.
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES
TEST
LEVEL
Serial Data Rate
0
-
622
Mb/s
1
Additive Jitter
270Mb/s
-
25
-
ps p-p
1
2
540Mb/s
-
25
-
622Mb/s
-
50
-
Output Rise/Fall Time
t
R
, t
F
20% - 80%
400
470
700
ps
3
Mismatch in Output
Rise/Fall Times
-
50
100
ps
1
Overshoot
-
5
8
%
1
Duty Cycle Distortion
-
50
100
ps
2
Output Return Loss
540MHz
-
17
-
dB
2
TEST LEVELS
1. 100% tested at 25C.
2. Guaranteed by design.
3. Correlated value.
NOTES
1. RMS additive jitter measured using Pseudo Random bit sequence (2
23
- 1).
2. Measured with Gennum Evaluation Board (EB-RD35).
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PIN CONNECTIONS
INPUT/OUTPUT CIRCUITS
Fig. 1 Input Circuit (pins 6 and 7)
Fig. 2 Output Circuit (pins 1 and 2)
SDO
SDO
V
EE
R
SET
V
CC
SDI
SDI
V
EE
GS9028
TOP VIEW
1
2
3
4
8
7
6
5
PIN DESCRIPTIONS
NUMBER
SYMBOL
TYPE
DESCRIPTION
1
SDO
O
Serial data output (inverse).
2
SDO
O
Serial data output.
4
R
SET
I
Output amplitude control resistor.
6
SDI
I
Serial data input (inverse).
7
SDI
I
Serial data input.
SDI
SDI
V
CC
R
SET
SDO
SDO
+
-
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S
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TYPICAL PERFORMACE CURVES (measured using the Typical Application Circuit)
Fig. 3 Output Eye Diagram 270Mb/s
Fig. 5 Output Eye Diagram 622Mb/s
Fig. 4 Output Eye diagram 540Mb/s
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S
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028
DETAILED DESCRIPTION
INPUT INTERFACING
SDI/SDI are high impedance differential inputs. Two
conditions must be observed when interfacing to these
inputs:
1. The input signal amplitude must be between 80mV and
1000mV.
2. The common mode voltage range must be as specified
in the DC Characteristics Table (page 2). For 800mV
input amplitude signals, this corresponds to a common
mode voltage range between 2.8 and 4.6 volts.
Figures 6 and 7 illustrate two methods of interfacing the
GS9028 to the Gennum GS9024 (Cable Equalizer), GS9035
(Reclocker) or the GS9025 (Receiver).
Figure 6 illustrates the simplest interface and is
recommended when the trace lengths between the driver
and the GS9028 are less than 0.5in. The pull up resistors
should be placed near the GS9028 to serve as end
terminations.
Fig. 6
When trace lengths become longer than 0.5in and data
rates greater than 360Mb/s, electromagnetic reflections
begin to affect signal integrity. To minimize reflections,
controlled impedance traces and source and end
terminations should be used as shown in Figure 7. Although
terminations on both sides reduce the signal swing by a
factor of two, the GS9028 is designed to meet this need
with ultra low input amplitude requirements (as low as
80mV). This low input amplitude requirement also allows the
use of 50
transmission lines (which are more robust and
easier to control in multilayer boards) to interconnect the
GS9024/25/35 and the GS9028.
Fig. 7
The GS9028 can also be configured to accept ac coupled
input signals. In this case, the inputs must be dc biased as
illustrated in Figure 8.
Fig. 8
The recommended values for R1 and R2 are:
R1 = 1.35Z
O
R2 = 3.85Z
O
where Z
O
is the transmission line characteristic impedance.
For 75
cable, R1 = 100
and R2 = 287
.
OUTPUT INTERFACING
Figure 9 illustrates the recommended interface for ac
coupled outputs.
Fig. 9
GS9024 or
GS9035 or
GS9025
GS9028
75
75
10nF
V
CC
+
_
+
_
GS9024 or
GS9035 or
GS9025
GS9028
+
_
+
_
V
CC
75
100nF
10nF
75
75
75
R1
R1
10nF
1F
1F
R2
R2
V
CC
GS9028
+
_
R
T
GS9028
R
R
T
= R = Z
O
GS9028
R
L
L
R
T
V
CC
+
_
10nF
1F
1F
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S
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The termination resistor (R
T
) value should be equal to the
characteristic impedance of the cable. Controlled
impedance traces should be used for the outputs and the
termination resistors should be placed near the GS9028.
The inductor (L) and resistor (R) are used to optimize the
output return loss and are PCB dependent. Typically, R
equals the transmission line characteristic impedance and
L is approximately 8.2nH.
OUTPUT AMPLITUDE ADJUSTMENT
The GS9028 outputs are adjustable from as low as 50mV to
as high as 1000mV. The output amplitude is set by the R
SET
resistor connected to pin 4. The relationship between the
output amplitude (V
OUT
) and R
SET
is approximately given by
the equation below:
R
SET
= (1.3696 x Z
O
)/(2 x V
OUT
) - 5.5
where Z
O
is in ohms and V
OUT
is in volts.
The minimum value of R
SET
is 46
. For 75
cable and
800mV output amplitudes, the value of R
SET
is 59
. Also,
note that the above formula assumes that the transmission
line is properly end terminated.
TYPICAL APPLICATION CIRCUIT
75
75
75
75
59
10n
8.2nH
1
1
1
100n
V
CC
R
SET
V
EE
SDO
SDO
V
EE
SDI
SDI
V
CC
V
CC
8.2nH
GS9028
4
3
2
1
5
6
7
8
All resistors in ohms, all capacitors in farads, unless otherwise shown.
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GENNUM CORPORATION
MAILING ADDRESS:
P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3
Tel. +1 (905) 632-2996 Fax. +1 (905) 632-5946
SHIPPING ADDRESS:
970 Fraser Drive, Burlington, Ontario, Canada L7L 5P5
GENNUM JAPAN CORPORATION
C-101, Miyamae Village, 2-10-42 Miyamae, Suginami-ku
Tokyo 168-0081, Japan
Tel. +81 (03) 3334-7700 Fax. +81 (03) 3247-8839
GENNUM UK LIMITED
Centaur House, Ancells Bus. Park, Ancells Rd, Fleet, Hants, England GU13 8UJ
Tel. +44 (0)1252 761 039 Fax +44 (0)1252 761 114
Gennum Corporation assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement.
Copyright April 1996 Gennum Corporation. All rights reserved. Printed in Canada.
G
S
9
028
PACKAGE DIMENSIONS
0.49 MAX
3.81
0.05
3 spaces @ 1.27
0.05
4.0
MAX
6.20
MAX
0.25
MAX
1
8
1.91
MAX
4
5
1.27 MAX
0.25
MAX
5.00 MAX.
0.60 MAX
=
=
=
8 pin SOIC
REVISION NOTES:
Updated to Data Sheet.
CAUTION
ELECTROSTATIC
SENSITIVE DEVICES
DO NOT OPEN PACKAGES OR HANDLE
EXCEPT AT A STATIC-FREE WORKSTATION
DOCUMENT IDENTIFICATION
DATA SHEET
The product is in production. Gennum reserves the right to make
changes at any time to improve reliability, function or design, in order to
provide the best product possible.
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