Down Converter
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FEATURES
APPLICATION
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
AGC IN1
AGC IN2
VAGC
GND
LO IN1
LO IN 2
VCC1
VCC2
MIXOUT1
MIXOUT2
GND
IF IN1
IF IN 2
GND
IFOUT1
IFOUT2
16-PIN TSSOP
(TOP VIEW)
DESCRIPTION
FUNCTIONAL BLOCK DIAGRAM
1
2
3
4
5
7
6
8
16
15
14
13
12
10
11
9
Mixer
Buffer
AGC IN1
AGC IN2
VAGC
GND
LO IN1
LO IN2
VCC 1
VCC2
MIXOUT1
MIXOUT2
IF IN1
GND
IFOUT 2
IF IN2
GND
IFOUT 1
IF Amplifier
AGC Amplifier
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
RF AGC Amplifier, Mixer, and IF Amplifier
Circuits
Low Distortion
5-V Power Supply
16-Pin TSSOP Package
CATV
The SN761688 is a monolithic IC designed as an out-of-band tuner for CATV. The circuit consists of an RF AGC
amplifier, mixer, and IF amplifier, and is available in a small-outline package.
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be
more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright 2006, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
www.ti.com
3
100 k
W
30 k
W
1
2
1 k
W
1 k
W
5
6
3 k
W
3 k
W
10
9
15
16
15
16
12
13
1 k
W
1 k
W
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
TERMINAL FUNCTIONS
TERMINAL
DESCRIPTION
SCHEMATIC
NAME
NO.
AGC IN1
1
Input of AGC amplifier
Figure 1
AGC IN2
2
VAGC
3
Input of gain control voltage
Figure 2
GND
4, 11, 14
Ground
LO IN1
5
Input of local OSC
Figure 3
LO IN2
6
VCC1
7
5 V power supply; AGC/Mixer/Buffer
VCC2
8
5 V power supply; IF amplifier
IF OUT1
9
Output of IF amplifier
Figure 4
IF OUT2
10
IF IN2
12
Input of IF amplifier
Figure 5
IF IN1
13
MIXOUT2
15
Output of Mixer
Figure 6
MIXOUT1
16
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
2
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ABSOLUTE MAXIMUM RATINGS
RECOMMENDED OPERATING CONDITIONS
DC ELECTRICAL CHARACTERISTICS
AC ELECTRICAL CHARACTERISTICS
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
over operating free-air temperature range (unless otherwise noted)
(1)
Supply voltage, V
CC
(2)
VCC1,2 (Pin 7, 8)
0.4 V to 6.5 V
Input voltage
(2)
V
IN
(Pins 1, 2, 3, 5, 6, 12, 13)
0.4 V to VCC
Continuous total dissipation, P
D
(3)
T
A
25C
775 mW
Maximum junction temperature, T
J
150C
(1)
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2)
Voltage values are with respect to the GND of the circuit.
(3)
Derating factor is 6.2 mW/
C for T
A
25C.
over operating free-air temperature range (unless otherwise noted)
MIN
NOM
MAX
UNIT
Supply voltage, V
CC
4.5
5
5.5
V
Operating free-air temperature, T
A
20
85
C
V
CC
= 5 V, T
A
= 25C, unless otherwise noted
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
I
CC
Supply current
No signal, V
AGC
= 0 V
67
mA
I
IAGC
Input current (VAGC)
V
AGC
= 3 V
22
33
A
V
AGCMAX
AGC voltage high at maximum gain
3
V
CC
V
V
AGCMIN
AGC voltage low at minimum gain
0
0.5
V
V
CC
= 5 V, T
A
= 25C, unless otherwise noted
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
AGC amplifier and mixer
(1)
GC
MAX
Maximum conversion gain
V
AGC
= 3 V
27
30
33
dB
GC
MIN
Minimum conversion gain
V
AGC
= 0 V
-21
-18
-15
dB
GCR
MIX
Gain control range
V
AGC
= 0 V to 3 V
48
dB
V
MIXOUT
Mixer output voltage
V
AGC
= 3 V, Single-ended output
117
dB
V
NF
Noise figure
(2)
V
AGC
= 3 V
10
dB
Third order intermodulation
f
IN1
= 79.5 MHz, f
IN2
= 80.5 MHz,
IM3
GMX
-60
dBc
distortion
V
OUT
= -10 dBm, V
AGC
= 3 V
f
IN1
= 79.5 MHz, f
IN2
= 80.5 MHz, V
AGC
OIP3
GMX
Output intercept point
20
dBm
= 3 V
IF amplifier
(3)
GV
IFMAX
Maximum voltage gain
V
AGC
= 3 V
51
dB
GV
IFMIN
Minimum voltage gain
V
AGC
= 0 V
46
dB
GVR
IF
Gain control range
V
AGC
= 0 V to 3 V
5
dB
Third order intermodulation
f
IN1
= 43.5 MHz, f
IN2
= 445 MHz,
IM3
IF
-60
dBc
distortion
V
IFOUT
= 1 dBm, V
AGC
= 3 V
V
IFOUT
IF amplifier output voltage
V
AGC
= 3 V, Single-ended output
122
dB
V
(1)
Measurement Circuit 1 except for Noise Figure measurement. AGC IN = 80 MHz/-37 dBm, LO IN = 36 MHz / -20 dBm, IF = 44 MHz,
unless otherwise noted.
(2)
Measurement Circuit 2.
(3)
Measurement Circuit 3. IF IN = 44 MHz / -50 dBm, unless otherwise noted.
3
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APPLICATION INFORMATION
MEASUREMENT CIRCUITS
1
16
2
15
3
14
4
13
VCC
SG
5
12
6
11
7
10
8
9
AGC IN1
AGC IN2
VAGC
GND
MIXOUT1
MIXOUT2
GND
IF IN1
LO IN1
LO IN2
VCC1
VCC2
IF IN2
GND
IF OUT2
IF OUT1
VCC
Spectrum
Analyzer
SG
0.1
m
F
50
W
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
50
W
50
W
50
W
50
W
50
W
1
16
2
15
3
14
4
13
VCC
5
12
6
11
7
10
8
9
AGC IN1
AGC IN2
VAGC
GND
MIXOUT1
MIXOUT2
GND
IF IN1
LO IN1
LO IN2
VCC1
VCC2
IF IN2
GND
IF OUT2
IF OUT1
VCC
SG
0.1
m
F
50
W
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
50
W
50
W
50
W
Noise Source
NF Meter
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
Figure 7. Measurement Circuit 1
Figure 8. Measurement Circuit 2
4
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1
16
2
15
3
14
4
13
VCC
SG
5
12
6
11
7
10
8
9
AGC IN1
AGC IN2
VAGC
GND
MIXOUT1
MIXOUT2
GND
IF IN1
LO IN1
LO IN2
VCC1
VCC2
IF IN2
GND
IF OUT2
IF OUT1
VCC
Spectrum
Analyzer
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
0.1
m
F
50
W
50
W
50
W
Vmeas
200
W
50
W
200
W
0.1
m
F
Vout = Vmeas + 14 dB
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
APPLICATION INFORMATION (continued)
Figure 9. Measurement Circuit 3
NOTE:
This application information is advisory and a performance check is required at the
actual application circuits.
Texas Instruments assumes no responsibility for the consequences of use of these
application circuits, such as infringement of intellectual property rights or other rights,
including patents, of third parties.
5
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TYPICAL CHARACTERISTICS
-30
-20
-10
0
10
20
30
40
0.0
0.5
1.0
1.5
2.0
2.5
3.0
AGC control voltage [V]
Gain [dB]
V
CC
= 4.5 V
V
CC
= 5 V
V
CC
= 5.5 V
T
A
= 25
5
C
-30
-20
-10
0
10
20
30
40
0.0
0.5
1.0
1.5
2.0
2.5
3.0
AGC control voltage [V]
Gain [dB]
T
A
= -20
5
C
T
A
= 25
5
C
T
A
= 85
5
C
V
CC
= 5 V
60
70
80
90
100
110
120
130
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
AGC IN Input Level [dBm]
MIXOUT Output Level [dBuV]
V
CC
= 4.5 V
V
CC
= 5 V
V
CC
= 5.5 V
T
A
= 25
5
C,
VAGC = 3 V
60
70
80
90
100
110
120
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
LO IN Input Level [dBm]
MIXOUT Output Level [dBuV]
T
A
= -20
5
C
T
A
= 25
5
C
T
A
= 85
5
C
V
CC
= 5 V,
VAGC = 3 V
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
Mixer Conversion Gain
Mixer Conversion Gain
vs
vs
AGC Control Voltage
AGC Control Voltage
Figure 10.
Figure 11.
Mixer Output Level
Mixer Output Level
vs
vs
AGC IN lnput Level
LO IN lnput Level
Figure 12.
Figure 13.
6
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5
10
15
20
25
30
35
40
0
10
20
30
40
50
Gain [dB]
NF [dB]
V
CC
= 5 V,
T
A
= 25
5
C
-120
-100
-80
-60
-40
-20
0
20
40
-70
-60
-50
-40
-30
-20
-10
0
AGC IN Input Level [dBm]
MIXOUT Output Level [dBm]
43.5 MHz
42.5 MHz
AGC IN = 79.5 MHz / 80.5 MHz,
LO IN = 36 MHz
V
CC
= 5 V, T
A
= 25
5
C
-30
-20
-10
0
10
20
30
40
0
100
200
300
400
500
600
AGC IN Input Freq [MHz]
MIXER GAIN [dB]
VAGC = 3 V
VAGC = 0 V
V
CC
= 5 V,
T
A
= 25
5
C
40
45
50
55
0.0
0.5
1.0
1.5
2.0
2.5
3.0
AGC control voltage [V]
Gain [dB]
V
CC
= 4.5 V
V
CC
= 5 V
V
CC
= 5.5 V
V
CC
= 5 V,
T
A
= 25
5
C
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
TYPICAL CHARACTERISTICS (continued)
Mixer NF
vs
Mixer IM3 (VAGC = 3 V)
Gain
Figure 14.
Figure 15.
IF Amp Gain
Mixer Frequency Response
vs
AGC Control Voltage
Figure 16.
Figure 17.
7
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-100
-80
-60
-40
-20
0
20
40
-80.0
-70.0
-60.0
-50.0
-40.0
-30.0
-20.0
-10.0
IF IN input level [dBm]
IFOUT output level [dBm]
43.5 MHz
42.5 MHz
V
CC
= 5 V,
T
A
= 25
5
C
IF IN = 43.5 MHz / 44.5 MHz
40
45
50
55
0.0
0.5
1.0
1.5
2.0
2.5
3.0
AGC control voltage [V]
Gain [dB]
T
A
= -20
5
C
T
A
= 25
5
C
T
A
= 85
5
C
V
CC
= 5 V
8.0
9.0
10.0
11.0
12.0
40.0
45.0
50.0
55.0
60.0
IFAMP Gain [dB]
NF [dB]
V
CC
= 5 V,
T
A
= 25
5
C
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
TYPICAL CHARACTERISTICS (continued)
IF Amp Gain
vs
IF Amp IM3 (AGC = 3 V)
AGC Control Voltage
Figure 18.
Figure 19.
IF Amp NF
vs
Gain
Figure 20.
8
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S-PARAMETER
SN761688
DOWN CONVERTER
SLES178 APRIL 2006
TYPICAL CHARACTERISTICS (continued)
Figure 21. AGC IN
Figure 22. IF IN
9
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SN761688
DOWN CONVERTER
SLES178 APRIL 2006
TYPICAL CHARACTERISTICS (continued)
Figure 23. IF OUT
10
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PACKAGING INFORMATION
Orderable Device
Status
(1)
Package
Type
Package
Drawing
Pins Package
Qty
Eco Plan
(2)
Lead/Ball Finish
MSL Peak Temp
(3)
SN761688PW
ACTIVE
TSSOP
PW
16
90
TBD
Call TI
Call TI
SN761688PWR
ACTIVE
TSSOP
PW
16
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
SN761688PWRG4
ACTIVE
TSSOP
PW
16
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent
for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com
22-May-2006
Addendum-Page 1
MECHANICAL DATA
MTSS001C JANUARY 1995 REVISED FEBRUARY 1999
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
PW (R-PDSO-G**)
PLASTIC SMALL-OUTLINE PACKAGE
14 PINS SHOWN
0,65
M
0,10
0,10
0,25
0,50
0,75
0,15 NOM
Gage Plane
28
9,80
9,60
24
7,90
7,70
20
16
6,60
6,40
4040064/F 01/97
0,30
6,60
6,20
8
0,19
4,30
4,50
7
0,15
14
A
1
1,20 MAX
14
5,10
4,90
8
3,10
2,90
A MAX
A MIN
DIM
PINS **
0,05
4,90
5,10
Seating Plane
0
8
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion not to exceed 0,15.
D. Falls within JEDEC MO-153
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI's terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Mailing Address:
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2006, Texas Instruments Incorporated
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