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FEATURES
• Single-Chip Mixer/Oscillator and PLL Synthesizer
• Three-Band Local Oscillator • I2C Bus Protocol (Bidirectional Data
Transmission) • 30-V Tuning Voltage Output • Four NPN-Type Band-Switch Drivers • Programmable Reference Divider Ratio (512,
640, or 1024 ) • 5-V Power Supply • 30-Pin TSSOP Package
APPLICATIONS
• TV • VCR/DVD Recorder • Set-Top Box
DESCRIPTION
The SN761681 is a synthesized tuner IC designed for TV tuning systems. The circuit consists of a PLL synthesizer, three-band local oscillator and mixer, 30-V output tuning amplifier, four NPN band-switch drivers, and is available in a small-outline package. A 15-bit programmable counter and reference divider are controlled by I2C bus protocol. Tuning step frequency is selectable by this reference divider ratio for a crystal oscillator.
SN761681 TV TUNER IC
SLES165 – DECEMBER 2005
DBT PACKAGE (TOP VIEW)
VHI OSC C VHI OSC B OSC GND VLO OSC C VLO OSC B UHF OSC B1 UHF OSC C1 UHF OSC C2 UHF OSC B2
IF GND VCC
IF OUT1 IF OUT2
CP VTU
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
30 UHF RF IN2 29 UHF RF IN1 28 VHF RF IN 27 RF GND 26 MIX OUT2 25 MIX OUT1 24 BS4 23 BS2 22 BS1 21 BS3 20 ADC 19 AS 18 SDA 17 SCL 16 XTAL
P0038-01
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. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.
Copyright © 2005, Texas Instruments Incorporated
SN761681 TV TUNER IC
SLES165 – DECEMBER 2005
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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.
Functional Block Diagram
VLO OSC B VLO OSC C OSC GND VHI OSC B VHI OSC C UHF OSC B1 UHF OSC C1 UHF OSC C2 UHF OSC B2 MIX OUT1 MIX OUT2 VCC
VHF-L Osc
VHF-H Osc
UHF Osc
IF Amp
VHF RF IN
VHF Mixer
UHF Mixer
UHF RF IN1 UHF RF IN2
RF GND XTAL
SCL SDA
AS
1/8 Prescaler
1/32, 1/33 Prescaler
15-Bit Counter
XTAL Osc 4 MHz
512/640/1024 Divider
I2C Bus Interface
Phase Detector
Charge Pump
NPN Band Switch Port
5-Level ADC
Op Amp
IF OUT1 IF OUT2 IF GND
CP VTU
ADC BS1 BS2 BS3 BS4
B0089-02
2
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TERMINAL NAME ADC AS BS1 BS2 BS3 BS4 CP IF GND IF OUT1 IF OUT2 MIX OUT1 MIX OUT2 OSC GND RF GND SCL SDA UHF OSC B1 UHF OSC B2 UHF OSC C1 UHF OSC C2 UHF RF IN1 UHF RF IN2 VCC VHF RF IN VHI OSC B VHI OSC C VLO OSC B VLO OSC C VTU XTAL
NO. 20 19 22 23 21 24 14 10 12 13 25 26 3 27 17 18 6 9 7 8 29 30 11 28 2 1 5 4 15 16
Pin Assignments
Pin Description
DESCRIPTION
ADC input Address selection input Band switch1 output (NPN emitter follower) Band switch2 output (NPN emitter follower) Band switch3 output (NPN emitter follower) Band switch4 output (NPN emitter follower) Charge pump output IF ground IF output IF output Mixer output Mixer output Oscillator ground RF ground Serial clock input Serial data input/output UHF oscillator base1 UHF oscillator base2 UHF oscillator collector1 UHF oscillator collector2 UHF RF input UHF RF input Supply voltage for mixer/oscillator/PLL: 5-V VHF RF input VHF HIGH oscillator base VHF HIGH oscillator collector VHF LOW oscillator base VHF LOW oscillator collector Tuning voltage amplifier output 4-MHz crystal oscillator input
150 kW
20 19 50 kW
SN761681 TV TUNER IC
SLES165 – DECEMBER 2005
SCHEMATIC
Figure 1 Figure 2 Figure 3 Figure 3 Figure 3 Figure 3 Figure 4
Figure 5 Figure 5 Figure 6 Figure 6
Figure 7 Figure 8 Figure 9 Figure 9 Figure 9 Figure 9 Figure 10 Figure 10
Figure 11 Figure 12 Figure 12 Figure 13 Figure 13 Figure 14 Figure 15
Figure 1.
S0133-03
S0159-01
Figure 2.
3
SN761681 TV TUNER IC
SLES165 – DECEMBER 2005
50 kW
21 22 23 24
S0138-02
Figure 3.
12 13
S0155-01
Figure 5.
17
S0136-03
Figure 7.
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14
S0156-01
Figure 4.
25 26
S0160-01
Figure 6.
18
Figure 8.
S0133-02
4
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8
9 3 kW
3 kW
7 6
Figure 9.
S0130-01
28
S0142-04
Figure 11. 4
5
3 kW
3 kW
SN761681 TV TUNER IC
SLES165 – DECEMBER 2005
29 30
S0142-05
Figure 10. 1
2
3 kW
3 kW
Figure 12. 15
S0129-01
S0129-02
Figure 13.
S0157-01
Figure 14.
5
SN761681 TV TUNER IC
SLES165 – DECEMBER 2005
16
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Figure 15.
S0158-01
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted) (1)
Supply voltage, VCC(2) Input voltage 1, VGND(2) Input voltage 2, VVTU(2) Input voltage 3, VIN(2) Continuous total dissipation, PD(3) Operating free-air temperature, TA Storage temperature range, Tstg Maximum junction temperature, TJ Maximum short-circuit time, tSC(max)
VCC (Pin 11) RF GND, OSC GND (Pins 3, 27) VTU Other pins (Pins 1, 2, 4–9, 12.