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GS9078A HD-LINX® II
Multi-Rate Cable Driver
GS9078A Data Sheet
34165 - 4 March 2006 1 of 14
Features
• SMPTE 259M and SMPTE 344M compliant
• Dual coaxial cable driving outputs with selectable
slew rate
•50Ω differential PECL input
• Pb-free and RoHS compliant
• Seamless interface to other HD-LINX® II family
products
• Single 3.3V power supply operation
• Operating temperature range: 0°C to 70°C
Applications
• SMPTE 259M and SMPTE 344M Coaxial Cable
Serial Digital Interfaces.
Description
The GS9078A is a second generation high-speed
BiCMOS integrated circuit designed to drive one or two
75Ω co-axial cables.
The GS9078A may drive data rates up to 540Mb/s and
provides two selectable slew rates in order to achieve
compliance to SMPTE 259M and SMPTE 344M.
The GS9078A accepts a LVPECL level differential input
that may be AC coupled. External biasing resistors at
the inputs are not required.
Power consumption is typically 168mW using a 3.3V
power supply. The GS9078A is Pb-free, and the
encapsulation compound does not contain halogenated
flame retardant.
This component and all homogeneous subcomponents
are RoHS compliant.
Functional Block Diagram
SDO
RSET
SDO
SDI
SDI
BANDGAP REFERENCE AND BIASING CIRCUIT
OUTPUT STAGE &
CONTROL
INPUT
DIFFERENTIAL
PAIR
GS9078A Data Sheet
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Contents
1. Pin Out ......................................................................................................................3
1.1 Pin Assignment ...............................................................................................3
1.2 Pin Descriptions ..............................................................................................3
2. Electrical Characteristics...........................................................................................4
2.1 Absolute Maximum Ratings ............................................................................4
2.2 Solder Reflow Profiles .....................................................................................4
2.3 DC Electrical Characteristics ..........................................................................5
2.4 AC Electrical Characteristics ...........................................................................6
3. Input / Output Circuits ...............................................................................................7
4. Detailed Description ..................................................................................................8
4.1 Input Interfacing ..............................................................................................8
4.2 Output Interfacing ...........................................................................................8
4.3 Output Return Loss Measurement ................................................................10
4.4 Output Amplitude (RSET) .............................................................................10
5. Application Information............................................................................................11
5.1 PCB Layout ...................................................................................................11
5.2 Typical Application Circuit .............................................................................11
6. Package & Ordering Information.............................................................................12
6.1 Package Dimensions ....................................................................................12
6.2 Recommended PCB Footprint ......................................................................13
6.3 Packaging Data .............................................................................................13
6.4 Ordering Information .....................................................................................13
7. Revision History ......................................................................................................14
GS9078A Data Sheet
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1. Pin Out
1.1 Pin Assignment
Figure 1-1: 16-Pin QFN
1.2 Pin Descriptions
GS9078A
(top view)
1
V
EE
SDI
SDI
2
3
4
SDO
SDO
VCC
12
11
10
9
57
68
NC
NC
NC
NC
13
14
15
16
Center Pad
(bottom of package)
NC
NC
NC
NC
RSET
NC
Table 1-1: Pin Descriptions
Pin Number Name Timing Type Description
1,2 SDI, SDI Analog Input Serial digital differential input.
3V
EE – Power Most negative power supply connection. Connect to GND.
4R
SET Analog Input External output amplitude control resistor.
5,6,7,8,10,
13,14,15,16
NC – – No Connect. Not bonded internally.
9V
CC – Power Most positive power supply connection. Connect to +3.3V.
11,12 SDO, SDO Analog Output Serial digital differential output.
– Center Pad – Power Connect to most negative power supply plane following the
recommendations in Recommended PCB Footprint on
page 13.
GS9078A Data Sheet
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2. Electrical Characteristics
2.1 Absolute Maximum Ratings
2.2 Solder Reflow Profiles
The device is manufactured with Matte-Sn terminations and is compatible with both
standard eutectic and Pb-free solder reflow profiles. MSL qualification was
performed using the maximum Pb-free reflow profile shown in Figure 2-1.The
recommended standard Pb reflow profile is shown in Figure 2-2.
Figure 2-1: Maximum Pb-free Solder Reflow Profile (Preferred)
Parameter Value
Supply Voltage -0.5V to 3.6 VDC
Input ESD Voltage 2kV
Storage Temperature Range -50°C < Ts < 125°C
Input Voltage Range (any input) -0.3 to (VCC +0.3)V
Operating Temperature Range 0°C to 70°C
Reflow Temperature 260°C
25˚C
150˚C
200˚C
217˚C
260˚C
250˚C
Time
Temperature
8 min. max
60-180 sec. max
60-150 sec.
20-40 sec.
3˚C/sec max
6˚C/sec max
GS9078A Data Sheet
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Figure 2-2: Standard Pb Reflow Profile (Pb-free package)
2.3 DC Electrical Characteristics
25˚C
100˚C
150˚C
183˚C
230˚C
220˚C
Time
Temperature
6 min. max
120 sec. max
60-150 sec.
10-20 sec.
3˚C/sec max
6˚C/sec max
Table 2-1: DC Electrical Characteristics
VDD = 3.3V, TA = 0°C to 70°C, unless otherwise shown
Parameter Symbol Conditions Min Typ Max Units
Supply Voltage VCC – 3.135 3.3 3.465 V
Power Consumption PDTA = 25°C – 168 – mW
Supply Current IsTA = 25°C – 51 64 mA
Output Voltage VCMOUT Common mode – VCC - VOUT –V
Input Voltage VCMIN Common mode 1.6 + ΔVSDI/2 – VCC - ΔVSDI/2 V
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2.4 AC Electrical Characteristics
Table 2-2: AC Electrical Characteristics
VDD = 3.3V, TA = 0°C to 70°C, unless otherwise shown
Parameter Symbol Conditions Min Typ Max Units Notes
Serial input data rate DRSDO – – – 540 Mb/s 1
Additive jitter – – – 20 – psp-p –
Rise/Fall time tr, tf– 400 – 800 ps 2
Mismatch in rise/fall time Utr, Utf– – –30ps –
Duty cycle distortion – – – – 100 ps –
Overshoot – – – – 8 % –
Output Return Loss ORL – 15 – – dB –
Output Voltage Swing VOUT Single Ended into 75Ω
external load
RSET = 750Ω
750 800 850 mVp-p –
Input Voltage Swing UVSDI Differential 300 – 2200 mVp-p –
NOTES:
1. The input coupling capacitor must be set accordingly for lower data rates.
2. Rise/Fall time measured between 20% and 80%.
GS9078A Data Sheet
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3. Input / Output Circuits
Figure 3-1: Differential Input Stage (SDI/SDI)
Figure 3-2: Differential Output Stage (SDO/SDO)
VCC
VCC
SDI SDI
10k 10k
5k
10k
Vcc
IREF
SDO SDO
GS9078A Data Sheet
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4. Detailed Description
4.1 Input Interfacing
S
DI/SDI are high impedance differential inputs. The equivalent input circuit is shown
in
Figure 3-1
.
Several conditions must be observed when interfacing to these inputs:
• The differential input signal amplitude must be between 300 and 2000mVpp.
• The common mode voltage range must be as specified in the DC Electrical
Characteristics on page 5.
• For input trace lengths longer than approximately 1cm, the inputs should be
terminated as shown in the Typical Application Circuit.
The GS9078A inputs are self-biased, allowing for simple AC coupling to the device.
For serial digital video, a minimum capacitor value of 4.7µF should be used to allow
coupling of pathological test signals. A tantalum capacitor is recommended.
4.2 Output Interfacing
The GS9078A outputs are current mode, and will drive 800mV into a 75Ω load.
These outputs are protected from accidental static damage with internal static
protection diodes.
The SMPTE 344M and SMPTE 259M standards require that the output of a cable
driver have a source impedance of 75Ω and a return loss of at least 15dB between
5MHz and 540MHz.
In order for an SDI output circuit using the GS9078A to meet this specification, the
output application circuit shown in Typical Application Circuit on page 11 is
recommended.
The value of L
COMP
will vary depending on the PCB layout, with a typical value of
5.6nH
. A 4.7µF capacitor is used for AC coupling the output of the device. This
value is chosen to ensure that pathological signals can be coupled without a
significant DC component occurring. Please see Application Information on
page 11 for more details.
GS9078A Data Sheet
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Figure 4-1: Output signal for 270Mb/s input
The output protection diodes act as a varactor (voltage controlled capacitor) as
shown in Figure 4-2. Therefore, when measuring return loss at the GS9078A
output, it is necessary to take the measurement for both a logic high and a logic low
output condition.
Consequently, the output capacitance of the device is dependent on the logic state
of the output.
Figure 4-2: Static Protection Diodes
SDO
SDO
GS9078A
GS9078A Data Sheet
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4.3 Output Return Loss Measurement
To perform a practical return loss measurement, it is necessary to force the
GS9078A output to a DC high or low condition. The actual measured return loss
will be based on the outputs being static at VCC or VCC-1.6V. Under normal
operating conditions the outputs of the device swing between VCC-0.4V and
VCC-1.2V, so the measured value of return loss will not represent the actual
operating return loss.
A simple method of calculating the values of actual operating return loss is to
interpolate the two return loss measurements. In this way, the values of return loss
are estimated at VCC-0.4V and VCC-1.2V based on the measurements at VCC and
VCC-1.6V.
The two values of return loss (high and low) will typically differ by several decibels.
If the measured return loss is RH for logic high and RL for logic low, then the two
values can be interpolated as follows:
RIH = RH- (RH-RL)/4 and
RIL = RL+(RH-RL)/4
where RIH is the interpolated logic high value and RIL is the interpolated logic low
value.
For example, if RH = -18dB and RL = -14dB, then the interpolated values are
RIH = -17dB and RIL = -15dB.
4.4 Output Amplitude (RSET)
The output amplitude of the GS9078A is set to 800mVp-p with a tolerance of ±7%
using an RSET resistor of 750Ω. A ±1% SMT resistor should be used.
The RSET resistor is part of the high speed output circuit of the GS9078A. The
resistor should be placed as close as possible to the RSET pin. In addition, the PCB
capacitance should be minimized at this node by removing the PCB groundplane
beneath the RSET resistor and the RSET pin.
NOTE: Only an RSET value of 750Ω ±1% should be used. Using other values for
RSET is not recommended.
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5. Application Information
5.1 PCB Layout
Special attention must be paid to component layout when designing serial digital
interfaces for SDTV.
An FR-4 dielectric can be used, however, controlled impedance transmission lines
are required for PCB traces longer than approximately 1cm. Note the following
PCB artwork features used to optimize performance:
• The PCB trace width for SD rate signals is closely matched to SMT
component width to minimize reflections due to changes in trace impedance.
• The PCB groundplane is removed under the GS9078A output components to
minimize parasitic capacitance.
• The PCB ground plane is removed under the GS9078A RSET pin and resistor
to minimize parasitic capacitance.
• Input and output BNC connectors are surface mounted in-line to eliminate a
transmission line stub caused by a BNC mounting via high speed traces which
are curved to minimize impedance variations due to change of PCB trace
width.
5.2 Typical Application Circuit
Figure 5-1: Typical Application Circuit
GS9078A
1
2
3
4
12
11
9
SDI
SDI
VEE
RSET
SDO
SDO
VCC
10n
75
5.6n
4u7
BNC
VCC
75
5.6n
10n 75
4u7
49.9
750
10n
49.9
4u7
75
BNC
VCC
4u7 VCC
* TYPICAL VALUE: VARIES WITH LAYOUT
DIFFERENTIAL
DATA INPUT
*
*
NOTE: All resistors in Ohms, capacitors in Farads,
and inductors in Henrys, unless otherwise noted.
GS9078A Data Sheet
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6. Package & Ordering Information
6.1 Package Dimensions
4.00+/-0.05
B
4.00+/-0.05
2X
2X
0.15
0.15
C
C
0.10 C
16X
0.08 C
SEATING PLANE
0.85+/-0.05
0.00-0.05
0.65/2
0.65
DETAIL B
SCALE:NTS
DATUM A OR B
TERMINAL TIP
0.20 REF
DATUM B
0.65
16X
0.35+/-0.05
0.10
0.05 C
AB
C
DATUM A
2.76+/-0.10
0.40+/-0.05
2.76+/-0.10
DETAIL B
CENTER TAB
PIN 1 AREA
A
C
GS9078A Data Sheet
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6.2 Recommended PCB Footprint
The Center Pad should be connected to the most negative power supply plane
(VEE) by a minimum of 5 vias.
NOTE: Suggested dimensions only. Final dimensions should conform to customer
design rules and process optimizations.
6.3 Packaging Data
6.4 Ordering Information
0.35
0.55
2.76
3.70
2.763.70
NOTE: All dimensions
are in millimeters.
0.65
CENTER PAD
Parameter Value
Package Type 4mm x 4mm 16-pin QFN
Package Drawing Reference JEDEC M0220
Moisture Sensitivity Level 3
Junction to Case Thermal Resistance, θj-c 31.0°C/W
Junction to Air Thermal Resistance, θj-a (at zero airflow) 43.8°C/W
Psi 11.0°C/W
Pb-free and RoHS compliant Yes
Part Number Package Temperature Range
GS9078A GS9078ACNE3 16-pin QFN 0°C to 70°C
CAUTION
ELECTROSTATIC SENSITIVE DEVICES
DO NOT OPEN PACKAGES OR HANDLE
EXCEPT AT A STATIC-FREE WORKSTATION
GENNUM CORPORATION
Mailing Address: P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3
Shipping Address: 970 Fraser Drive, Burlington, Ontario, Canada L7L 5P5
Tel. +1 (905) 632-2996 Fax. +1 (905) 632-5946
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
25 Long Garden Walk, Farnham, Surrey, England GU9 7HX
Tel. +44 (0)1252 747 000 Fax +44 (0)1252 726 523
Gennum Corporation assumes no liability for any errors or omissions in this document, or for the use of the
circuits or devices described herein. The sale of the circuit or device described herein does not imply any
patent license, and Gennum makes no representation that the circuit or device is free from patent infringement.
GENNUM and the G logo are registered trademarks of Gennum Corporation.
© Copyright 2005 Gennum Corporation. All rights reserved. Printed in Canada.
www.gennum.com
GS9078A Data Sheet
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14
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DOCUMENT IDENTIFICATION
DATA SHEET
The product is in production. Gennum reserves the right to make
changes to the product at any time without notice to improve reliability,
function or design, in order to provide the best product possible.
7. Revision History
Version ECR PCN Date Changes and/or Modifications
A 135926 –February 2005 New document.
0 136048 –February 2005 Converting to Preliminary Data Sheet.
Added PCB Layout section. Updated
Typical Application Circuit.
1 136655 –June 2005 Converted to Data Sheet. Changed title
of Figure 2-2 to clarify that this is the Pb
reflow profile. Updated Additive Jitter
number in AC Electrical Characteristics
table to be typically 20psp-p. Updated
dimensions of the center pad of the PCB
footprint in Section 6.2 to match the
dimensions of the center pad of the
device. Corrected part number in
ordering information. Rephrased the
RoHS Compliant statement.
2 137887 –September 2005 Corrected process to BiCMOS.
3 139115 38124 January 2006 Corrected Input Differential Swing to
2200mV.
4 139636 38695 March 2006 Corrected pad standoff height and
tolerances for pad width & package
dimension. Corrected pad shape.
