Samsung sn761678b Service manual

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FEATURES

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30

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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OUT

CP

VTU

XTAL

UHFRFIN
VHFRFIN
BS4
RFGND
MIXOUT2
MIXOUT1
IFIN2
IFIN1
BS2

BS1

BS3
ADC
AS
SDA
SCL

DBTPACKAGE

(TOP VIEW)

P0038-01

• Single-Chip Mixer/Oscillator and

Phase-Locked Loop (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)

• External 4-Pin Intermediate Frequency (IF)

Filter Between Mixer Output and IF Amplifier
Input

• 5-V Power Supply

• 30-Pin Thin Shrink Small-Outline Package

(TSSOP)

APPLICATIONS

• TVs

• VCR/DVD Recorders

• Set-Top Boxes

SN761678B

TV TUNER IC

SLES185 – JUNE 2006

DESCRIPTION

The SN761678B is a synthesized tuner IC designed for TV tuning systems. The circuit consists of a
phase-locked loop (PLL) synthesizer, three-band local oscillator and mixer, 30-V output tuning amplifier, and four
NPN band-switch drivers. The device 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.

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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.

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.

Copyright © 2006, Texas Instruments Incorporated

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B0089-02

IF
Amplifier

Operational
Amplifier

XTAL

Oscillator

4MHz

1/8

Prescaler

512/640/1024

Divider

1/32,1/33
Prescaler

Phase

Detector

15-Bit

Counter

Charge

Pump

I CBus

2

Interface

5-Level

ADC

IFOUT

IFGND

VTU

CP

VHFRFIN

UHFRFIN

RFGND

XTAL

SCL

SDA

AS

NPNBand-SwitchPort

VLOOSCB

VHIOSCC

OSCGND

VLOOSCC

VHIOSCB

UHFOSCB1

UHFOSCC1

UHFOSCC2

UHFOSCB2

MIXOUT1

MIXOUT2

VCC

BS1

ADC

BS2

BS3

BS4

VHF-L

Oscillator

VHF-H

Oscillator

UHF

Oscillator

VHF

Mixer

UHF

Mixer

IFIN2

IFIN1

SN761678B
TV TUNER IC

SLES185 – JUNE 2006

FUNCTIONAL BLOCK DIAGRAM

2

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18

S0159-01

150kW

50kW

19

S0133-03

SN761678B

TV TUNER IC

SLES185 – JUNE 2006

Terminal Functions

TERMINAL

NAME NO.

ADC 19 ADC input Figure 1
AS 18 Address selection input Figure 2
BS1 21 Band-switch 1 output (NPN emitter follower) Figure 4
BS2 22 Band-switch 2 output (NPN emitter follower) Figure 4
BS3 20 Band-switch 3 output (NPN emitter follower) Figure 4
BS4 28 Band-switch 4 output (NPN emitter follower) Figure 4
CP 13 Charge-pump output Figure 5
IF GND 10 IF ground
IF IN1 23 IF amplifier input 1 Figure 3
IF IN2 24 IF amplifier input 2 Figure 3
IF OUT 12 IF output Figure 6
MIX OUT1 25 Mixer output 1 Figure 7
MIX OUT2 26 Mixer output 2 Figure 7
OSC GND 3 Oscillator ground
RF GND 27 RF ground
SCL 16 Serial clock input Figure 8
SDA 17 Serial data input/output Figure 9
UHF OSC B1 6 UHF oscillator base 1 Figure 10
UHF OSC B2 9 UHF oscillator base 2 Figure 10
UHF OSC C1 7 UHF oscillator collector 1 Figure 10
UHF OSC C2 8 UHF oscillator collector 2 Figure 10
UHF RF IN 30 UHF RF input Figure 11
VCC 11 Supply voltage for mixer/oscillator/PLL: 5 V
VHF RF IN 29 VHF RF input Figure 12
VHI OSC B 2 VHF HIGH oscillator base Figure 13
VHI OSC C 1 VHF HIGH oscillator collector Figure 13
VLO OSC B 5 VHF LOW oscillator base Figure 14
VLO OSC C 4 VHF LOW oscillator collector Figure 14
VTU 14 Tuning voltage amplifier output Figure 15
XTAL 15 4-MHz crystal oscillator input Figure 16

DESCRIPTION SCHEMATIC

Figure 1. Figure 2.

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3

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20p

20p

23

24

22

28

21

20

S0138-02

50kW

12

S0155-01

13

S0156-01

S0160-01

25

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S0136-03

SN761678B
TV TUNER IC

SLES185 – JUNE 2006

Figure 3. Figure 4.

4

Figure 5. Figure 6.

Figure 7. Figure 8.

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17

S0133-02

8

9

7

6

3kW3kW

S0130-01

S0142-05

30

S0142-04

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S0129-01

3kW3kW

1

2

S0129-02

3kW3kW

4

5

Figure 9. Figure 10.

SN761678B

TV TUNER IC

SLES185 – JUNE 2006

Figure 11. Figure 12.

Figure 13. Figure 14.

5

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S0158-01

15

14

S0157-01

SN761678B
TV TUNER IC

SLES185 – JUNE 2006

Figure 15. Figure 16.

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)

Supply voltage range, V
Input voltage 1, V
Input voltage 2, V
Input voltage 3, V

GND
VTU
IN

Continuous total dissipation, P
Operating free-air temperature range, T
Storage temperature range, T
Maximum junction temperature, T
Maximum short-circuit time, t

(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 IF GND of the circuit.
(3) Derating factor is 8.57 mW/ ° C for TA≥ 25 ° C.

(2)

CC

(2)

(2)

(2)

(3)

D

A

stg

J

SC(max)

VCC (pin 11) –0.4 V to 6.5 V
OSC GND, RF GND (pins 3, 27) –0.4 V to 0.4 V
VTU (pin 14) –0.4 V to 35 V
Other pins (1, 2, 4–9, 12, 13, 15–26, 28–30) –0.4 V to 6.5 V
TA≤ 25 ° C 1071 mW

Each pin to V

(1)

or to GND 10 s

CC

–20 ° C to 85 ° C

–65 ° C to 150 ° C

150 ° C

Recommended Operating Conditions

Supply voltage, V
Tuning supply voltage, V
Output current of band switch, I
Operating free-air temperature, T

6

CC

TU

MIN NOM MAX UNIT

4.5 5 5.5 V
30 33 V

BS

A

One port on 10 mA

–20 85 ° C

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