GENNUM GS9028

GENLINX ™II GS9028 Cable Driver
with Two Adjustable Outputs
DATA SHEET
FEATURES
DESCRIPTION
• SMPTE 259M compliant
The GS9028 is a second generation bipolar integrated
circuit designed to drive two 75Ω co-axial cables.
• operational from DC to 622Mb/s
• nominal 470ps rise and fall times
• < ±7% output amplitude control
• 45% system power reduction over the GS9008
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 RSET resistor value.
• no external pulldown resistors required
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.
• input hysteresis
• operational down to 80mV input amplitude
• operates from a single +5 or -5 volt supply
• 8 pin SOIC
• Pb-free and Green
The GS9028 is packaged in an 8 pin SOIC and operates
from a single +5 or -5 volt supply.
APPLICATIONS
4ƒsc, 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.
ORDERING INFORMATION
PART NUMBER
PACKAGE
TEMPERATURE
Pb-FREE AND GREEN
GS9028-CKA
8 pin SOIC
0°C to 70°C
No
GS9028-CTA
8 pin SOIC Tape
0°C to 70°C
No
GS9028-CKAE3
8 pin SOIC
0°C to 70°C
Yes
GS9028-CTAE3
8 pin SOIC Tape
0°C to 70°C
Yes
BANDGAP REFERENCE AND BIASING CIRCUIT
SDI
SDI
INPUT
DIFFERENTIAL
PAIR WITH
HYSTERESIS
OUTPUT STAGE
& RISE/FALL TIME
CONTROL CIRCUIT
RSET
SDO
SDO
BLOCK DIAGRAM
Revision Date: June 2004
Document No. 521 - 68 - 05
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: [email protected]
www.gennum.com
GS9028
• two complementary outputs, adjustable from 50 to
1000mVp-p into 75Ω loads
ABSOLUTE MAXIMUM RATINGS
TA = 25°C unless otherwise specified
PARAMETER
VALUE
Supply Voltage
5.5V
GS9028
Input Voltage Range (any input)
-0.3 to (VCC +0.3)V
Operating Temperature Range
0 to 70°C
Storage Temperature
-65 to 150°C
Lead Temperature (soldering, 10 sec)
260°C
DC ELECTRICAL CHARACTERISTICS
VCC = 5V, TA = 0°C to 70°C unless otherwise shown. Specifications assume 800mV output amplitude levels into end terminated 75Ω transmission lines.
PARAMETER
SYMBOL
CONDITIONS
NOTES
TEST
LEVEL
MIN
TYP
MAX
UNITS
4.75
5.00
5.25
V
1
-
165
195
mW
3
Supply Voltage
VCC
System Power
Consumption
PD
Supply Current
ΙS
-
33
39
mA
3
Common Mode Input
Voltage Range
VCM,IN
2.4+(VDIFF/2)
-
VCC-(VDIFF/2)
V
2
Differential Input
VDIFF
80
-
1000
mV
2
VCM,OUT
-
VCC-VOUT
-
V
2
750
800
850
mV
1
10
-
-
mV
2
Common Mode
Output Voltage Range
Differential Output
VOUT
Driving two 75Ω
cables
RSET = 59Ω
Input Hysteresis
AC ELECTRICAL CHARACTERISTICS
VCC = 5V, TA = 0°C to 70°C unless otherwise shown. Specifications assume 800mV output amplitude levels into end terminated 75Ω transmission lines.
PARAMETER
SYMBOL
CONDITIONS
TYP
MAX
UNITS
0
-
622
Mb/s
270Mb/s
-
25
-
ps p-p
540Mb/s
-
25
-
622Mb/s
-
50
-
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
-
17
-
dB
Serial Data Rate
Additive Jitter
Output Rise/Fall Time
tR, tF
20% - 80%
Output Return Loss
540MHz
TEST LEVELS
NOTES
1. 100% tested at 25°C.
1. RMS additive jitter measured using Pseudo Random bit sequence (2
2. Guaranteed by design.
2. Measured with Gennum Evaluation Board (EB-RD35).
3. Correlated value.
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521 - 68 - 05
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- 1).
NOTES
TEST
LEVEL
MIN
1
1
2
2
PIN CONNECTIONS
8
VCC
7
GS9028
3 TOP VIEW 6
SDI
5
VEE
SDO
1
SDO
2
VEE
GS9028
4
RSET
SDI
PIN DESCRIPTIONS
NUMBER
SYMBOL
TYPE
DESCRIPTION
1
SDO
O
Serial data output (inverse).
2
SDO
O
Serial data output.
4
RSET
I
Output amplitude control resistor.
6
SDI
I
Serial data input (inverse).
7
SDI
I
Serial data input.
INPUT/OUTPUT CIRCUITS
VCC
SDO
SDO
SDI
SDI
+
RSET
Fig. 1 Input Circuit (pins 6 and 7)
Fig. 2 Output Circuit (pins 1 and 2)
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GS9028
TYPICAL PERFORMACE CURVES (measured using the Typical Application Circuit)
Fig. 3 Output Eye Diagram 270Mb/s
Fig. 4 Output Eye diagram 540Mb/s
Fig. 5 Output Eye Diagram 622Mb/s
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DETAILED DESCRIPTION
INPUT INTERFACING
VCC
100nF
SDI/SDI are high impedance differential inputs. Two
conditions must be observed when interfacing to these
inputs:
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).
+
_
_
GS9024 or
GS9035 or
GS9025
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.
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.
VCC
10nF
R1
1µF
_
1µF
R2
GS9028
R2
75Ω
+
+
_
_
GS9024 or
GS9035 or
GS9025
R1
+
VCC
10nF
75Ω
75Ω
75Ω
75Ω
75Ω
+
GS9028
1. The input signal amplitude must be between 80mV and
1000mV.
10nF
Fig. 8
GS9028
The recommended values for R1 and R2 are:
R1 = 1.35ZO
Fig. 6
R2 = 3.85ZO
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 50Ω transmission lines (which are more robust and
easier to control in multilayer boards) to interconnect the
GS9024/25/35 and the GS9028.
where ZO is the transmission line characteristic impedance.
For 75Ω cable, R1 = 100Ω and R2 = 287Ω.
OUTPUT INTERFACING
Figure 9 illustrates the recommended interface for ac
coupled outputs.
VCC
RT = R = ZO
10nF
R
RT
RT
L
1µF
L
1µF
+
GS9028
_
R
GS9028
Fig. 9
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GS9028
The termination resistor (RT) 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 RSET
resistor connected to pin 4. The relationship between the
output amplitude (VOUT) and RSET is approximately given by
the equation below:
RSET = (1.3696 x ZO)/(2 x VOUT) - 5.5
where ZO is in ohms and VOUT is in volts.
The minimum value of RSET is 46Ω. For 75Ω cable and
800mV output amplitudes, the value of RSET is 59Ω. Also,
note that the above formula assumes that the transmission
line is properly end terminated.
TYPICAL APPLICATION CIRCUIT
5
6
7
8
4
VEE
RSET
SDI
VEE
59
3
GS9028
75
2
SDI
SDO
VCC
SDO
1
1µ
75
75
8.2nH
1µ
8.2nH
1µ
75
100n
10n
VCC
VCC
All resistors in ohms, all capacitors in farads, unless otherwise shown.
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PACKAGE DIMENSIONS
5.00 MAX.
1.91
MAX
0.49 MAX
1.27 MAX
5
8
0.25
MAX
6.20
MAX
GS9028
4.0
MAX
4
1
0.25
MAX
=
=
=
0.60 MAX
3.81 ±0.05
3 spaces @ 1.27 ±0.05
8 pin SOIC
CAUTION
ELECTROSTATIC
SENSITIVE DEVICES
DO NOT OPEN PACKAGES OR HANDLE
EXCEPT AT A STATIC-FREE WORKSTATION
DOCUMENT IDENTIFICATION
REVISION NOTES:
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.
Added lead-free and green information.
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
Shinjuku Green Tower Building 27F 6-14-1, Nishi Shinjuku Shinjuku-ku,
Tokyo 160-0023 Japan
Tel: +81 (03) 3349-5501 Fax: +81 (03) 3349-5505
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.
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