GENNUM GS1578A

GS1578A HD-LINX® II
Multi-Rate Dual Slew-Rate Cable Driver
GS1578A Data Sheet
Features
Description
•
SMPTE 292M, SMPTE 344M and SMPTE 259M
compliant
•
Dual coaxial cable driving outputs with selectable
slew rate
The GS1578A is a second generation high-speed
BiCMOS integrated circuit designed to drive one or two
75Ω co-axial cables.
•
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 292M, SMPTE 344M and SMPTE 259M
Coaxial Cable Serial Digital Interfaces.
The GS1578A may drive data rates up to 1.485Gb/s
and provides two selectable slew rates in order to
achieve compliance to SMPTE 259M, SMPTE 344M
and SMPTE 292M.
The GS1578A 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 GS1578A is Pb-free, and the
encapsulation compound does not contain halogenated
flame retardant.
This component and all homogeneous subcomponents
are RoHS compliant.
BANDGAP REFERENCE AND BIASING CIRCUIT
SDI
INPUT
DIFFERENTIAL
PAIR
RSET
SDO
OUTPUT STAGE &
CONTROL
SDI
SDO
SD/HD
Functional Block Diagram
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GS1578A Data Sheet
Contents
Features ........................................................................................................................1
Applications...................................................................................................................1
Description ....................................................................................................................1
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 ................................................................11
4.4 Output Amplitude (RSET) .............................................................................11
5. Application Information............................................................................................12
5.1 PCB Layout ...................................................................................................12
5.2 Typical Application Circuit .............................................................................12
6. Package & Ordering Information .............................................................................13
6.1 Package Dimensions ....................................................................................13
6.2 Recommended PCB Footprint ......................................................................14
6.3 Packaging Data .............................................................................................14
6.4 Ordering Information .....................................................................................14
7. Revision History ......................................................................................................15
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GS1578A Data Sheet
1. Pin Out
SDI
1
SDI
2
NC
NC
NC
NC
1.1 Pin Assignment
16
15
14
13
12
SDO
11
SDO
GS1578A
(top view)
VEE
3
10
SD / HD
RSET
4
9
VCC
8
NC
NC
NC
7
NC
6
5
Center Pad
(bottom of package)
Figure 1-1: 16-Pin QFN
1.2 Pin Descriptions
Table 1-1: Pin Descriptions
Pin Number
Name
Timing
Type
Description
1,2
SDI, SDI
Analog
Input
Serial digital differential input.
3
VEE
–
Power
Most negative power supply connection. Connect to GND.
4
RSET
Analog
Input
External output amplitude control resistor.
5,6,7,8,13,14,
15,16
NC
–
–
No Connect. Not bonded internally.
9
VCC
–
Power
Most positive power supply connection. Connect to +3.3V.
10
SD/HD
Non
Synchronous
Input
Output slew rate control. When set HIGH, the output will meet
SMPTE 259M rise/fall time specifications. When set LOW, the
serial outputs will meet SMPTE 292M rise/fall time
specifications.
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 14.
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2. Electrical Characteristics
2.1 Absolute Maximum Ratings
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
Solder Reflow Temperature
260°C
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.
Temperature
60-150 sec.
20-40 sec.
260˚C
250˚C
3˚C/sec max
217˚C
6˚C/sec max
200˚C
150˚C
25˚C
Time
60-180 sec. max
8 min. max
Figure 2-1: Maximum Pb-free Solder Reflow Profile (Preferred)
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GS1578A Data Sheet
60-150 sec.
Temperature
10-20 sec.
230˚C
220˚C
3˚C/sec max
183˚C
6˚C/sec max
150˚C
100˚C
25˚C
Time
120 sec. max
6 min. max
Figure 2-2: Standard Pb Reflow Profile (Pb-free package)
2.3 DC Electrical Characteristics
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
PD
TA = 25°C
–
168
–
mW
Supply Current
Is
TA = 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
SD/HD Input
VIH
–
2.4
–
–
V
VIL
–
–
–
0.8
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
–
–
–
1.485
Gb/s
1
Additive jitter
–
1.485Gb/s
–
22
–
psp-p
–
–
270Mb/s
–
20
–
psp-p
–
tr, tf
SD/HD=0
–
–
220
ps
2
tr, tf
SD/HD=1
400
–
800
ps
2
Mismatch in rise/fall time
Utr, Utf
–
–
–
30
ps
–
Duty cycle distortion
–
SD/HD=0
–
–
30
ps
–
–
SD/HD=1
–
–
100
ps
–
–
SD/HD=0
–
–
10
%
–
–
SD/HD=1
–
–
8
%
–
Output Return Loss
ORL
–
15
–
–
dB
–
Output Voltage Swing
VOUT
Single Ended into 75Ω
external load
750
800
850
mVp-p
–
300
–
2000
mVp-p
–
Rise/Fall time
Overshoot
RSET = 750Ω
Input Voltage Swing
UVSDI
Differential
NOTES:
1. The input coupling capacitor must be set accordingly for lower data rates.
2. Rise/Fall time measured between 20% and 80%.
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3. Input / Output Circuits
VCC
SDI
SDI
VCC
10k
5k
10k
10k
Figure 3-1: Differential Input Stage (SDI/SDI)
Vcc
SDO SDO
IREF
Figure 3-2: Differential Output Stage (SDO/SDO)
VCC
On Chip
Reference
SD/HD
Figure 3-3: Slew Rate Select Input Stage
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GS1578A Data Sheet
4. Detailed Description
4.1 Input Interfacing
SDI/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 GS1578A 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.
SD/HD Input Pin
The GS1578A SDO rise and fall times can be set to comply with both SMPTE
259M/344M and SMPTE 292M. For all SMPTE 259M standards, or any data rate
that requires longer rise and fall time characteristics, the SD/HD pin must be set
HIGH by the application layer. For SMPTE 292M standards and signals which
require faster rise and fall times, this pin should be set LOW.
4.2 Output Interfacing
The GS1578A 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 292M, 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 1.485GHz.
In order for an SDI output circuit using the GS1578A to meet this specification, the
output application circuit shown in Typical Application Circuit on page 12 is
recommended.
The value of LCOMP 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 12 for more details.
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GS1578A Data Sheet
Figure 4-1: Output signal for 270Mb/s input
Figure 4-2: Output signal for 1.485Gb/s input
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GS1578A Data Sheet
The output protection diodes act as a varactor (voltage controlled capacitor) as
shown in Figure 4-3. Therefore, when measuring return loss at the GS1578A
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.
GS1578A
SDO
SDO
Figure 4-3: Static Protection Diodes
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GS1578A Data Sheet
4.3 Output Return Loss Measurement
To perform a practical return loss measurement, it is necessary to force the
GS1578A 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 GS1578A 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 GS1578A. 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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GS1578A Data Sheet
5. Application Information
5.1 PCB Layout
Special attention must be paid to component layout when designing serial digital
interfaces for HDTV.
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 HD 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 GS1578A output components to
minimize parasitic capacitance.
•
The PCB ground plane is removed under the GS1578A 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
*
5.6n
75
4u7
49.9
DIFFERENTIAL
DATA INPUT
10n
1
2
3
4
49.9
GS1578A
SDI
SDI
VEE
RSET
SDO
SDO
SD/HD
VCC
12
11
10
9
75
75
VCC
750
VCC
10n
75
*
5.6n
4u7
BNC
4u7
BNC
4u7
* TYPICAL VALUE: VARIES WITH LAYOUT
VCC
10n
SD/HD
NOTE: All resistors in Ohms, capacitors in Farads,
and inductors in Henrys, unless otherwise noted.
Figure 5-1: Typical Application Circuit
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GS1578A Data Sheet
6. Package & Ordering Information
6.1 Package Dimensions
A
2.76+/-0.10
0.40+/-0.05
4.00+/-0.05
DATUM A
PIN 1 AREA
2X
2.76+/-0.10
4.00+/-0.05
B
CENTER TAB
DETAIL B
0.15 C
DATUM B
0.15 C
2X
0.35+/-0.05
0.65
0.20 REF
16X
0.10 C
C
0.10
CAB
0.05
C
DATUM A OR B
16X
0.08 C
SEATING PLANE
0.65/2
0.00-0.05
0.85+/-0.05
TERMINAL TIP
0.65
DETAIL B
SCALE:NTS
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GS1578A Data Sheet
6.2 Recommended PCB Footprint
0.35
0.65
0.55
3.70
2.76
CENTER PAD
NOTE: All dimensions
are in millimeters.
2.76
3.70
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
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
6.4 Ordering Information
GS1578A
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Part Number
Package
Temperature Range
GS1578ACNE3
16-pin QFN
0°C to 70°C
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GS1578A Data Sheet
7. Revision History
Version
ECR
PCN
Date
Changes and/or Modifications
A
135502
–
February 2005
New document.
0
136045
–
February 2005
Convert to Preliminary Data Sheet.
1
137132
–
June 2005
Converted to Data Sheet. Changed title
of Figure 2-2 to clarify that it is the Pb
reflow profile. Updated SD additive jitter
number in the AC electrical
characteristics table to be typically
20psp-p. Updated dimensions on 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
137885
–
September 2005
Corrected process to BiCMOS. Updated
eye diagrams in Section 4.2.
3
139113
38124
January 2006
Corrected Input Differential Swing to
2200mV.
4
139637
38695
March 2006
Corrected pad standoff height and
tolerances for pad width & package
dimension. Corrected pad shape.
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 to the product at any time without notice to improve reliability,
function or design, in order to provide the best product possible.
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
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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
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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.
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