Philips TDA4686WP, TDA4686 Datasheet

INTEGRATED CIRCUITS

DATA SH EET

TDA4686

Video processor with automatic
cut-off control

Product specification
Supersedes data of May 1993
File under Integrated Circuits, IC02

1997 Jun 23

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

FEATURES

• Intended for double line frequency application
(100/120 Hz)

• Operates from an 8 V DC supply

• Black level clamping of the colour difference, luminance

and RGB input signals with coupling-capacitor DC level
storage

• Two analog RGB inputs, selected either by fast switch
signals or via I2C-bus; brightness and contrast control of
both RGB inputs

• Saturation, contrast, brightness and white adjustment

2

C-bus

via I

• Same RGB output black levels for Y/CD and RGB input
signals

• Timing pulse generation from either a 2 or 3-level
sandcastle pulse for clamping, vertical synchronization
and cut-off timing pulses

• Automatic cut-off control or clamped output selectable
via I2C-bus

• Automatic cut-off control with picture tube leakage
current compensation

• Cut-off measurement pulses after end of the vertical
blanking pulse or end of an extra vertical flyback pulse

• Increased RGB signal bandwidths

• Two switch-on delays to prevent discolouration before

steady-state operation

• Average beam current and peak drive limiting

• PAL/SECAM or NTSC matrix selection via I2C-bus

• Emitter-follower RGB output stages to drive the video

output stages

• I2C-bus controlled DC output e.g. for hue-adjust of
NTSC (multistandard) decoders

• No delay of clamping pulse

• Large luminance, colour difference and RGB bandwidth.

The required input signals are:

• Luminance and negative colour difference signals

• 2 or 3-level sandcastle pulse for internal timing pulse

generation

2

C-bus data and clock signals for microcontroller

• I
control.

Two sets of analog RGB colour signals can also be
inserted, e.g. one from a peritelevision connector and the
other from an on-screen display generator. The TDA4686
includes full I2C-bus control of all parameters and
functions with automatic cut-off control of the picture tube
cathode currents. It provides RGB output signals for the
video output stages.

The TDA4686 is a simplified, pin compatible (except for
pin 18) version of the TDA4680. The module address via
I2C-bus can be used for both ICs; where a function is not
included in the TDA4686 the I2C-bus command is not
executed. The differences with the TDA4680 are:

• No automatic white level control; the white levels are
determined directly by the I2C-bus data

• RGB reference levels for automatic cut-off control are
not adjustable via I2C-bus

• No clamping delay

• Only contrast and brightness adjust for the RGB input

signals

• The measurement lines are triggered either by the
trailing edge of the vertical component of the sandcastle
pulse or by the trailing edge of an optional external
vertical flyback pulse (on pin 18), according to which
occurs first.

GENERAL DESCRIPTION

The TDA4686 is a monolithic integrated circuit with a
luminance and a colour difference interface for video
processing in TV receivers. Its primary function is to
process the luminance and colour difference signals from
a colour decoder which is equipped e.g. with the
multistandard decoder TDA4655 or TDA9160 plus delay
line TDA4661 and the Picture Signal Improvement (PSI)
IC, TDA467X, or from a feature module.

1997 Jun 23 2

The TDA4685 is like TDA4686 but intended for normal line
frequency application.

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

QUICK REFERENCE DATA

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

V

P

I

P

V

8(p-p)

V

6(p-p)

V

7(p-p)

V

14

V

i(p-p)

V

o(b-w)

T

amb

supply voltage (pin 5) 7.2 8.0 8.8 V
supply current (pin 5) − 60 − mA
luminance input (peak-to-peak value) − 0.45 − V

−(B − Y) input (peak-to-peak value) − 1.33 − V

−(R − Y) input (peak-to-peak value) − 1.05 − V

3-level sandcastle pulse

H+V − 2.5 − V
H − 4.5 − V
BK − 8.0 − V

2-level sandcastle pulse

H+V − 2.5 − V
BK − 4.5 − V

RGB input signals at pins 2, 3, 4, 10, 11and12

− 0.7 − V

(peak-to-peak value)
RGB outputs at pins 24, 22 and 20 (black-to-white value) − 2.0 − V
operating ambient temperature 0 − 70 °C

ORDERING INFORMATION

PACKAGE

TYPE NUMBER

NAME DESCRIPTION VERSION

TDA4686 DIP28 plastic dual in-line package; 28 leads (600 mil) SOT117-1
TDA4686WP PLCC28 plastic leaded chip carrier; 28 leads SOT261-2

1997 Jun 23 3

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

BLOCK DIAGRAM

RGB

outputs

O

O

R

G

242220

OUTPUT

ADJUST,

CUT-OFF

R

G

O

B

STAGES

B

MED715

21 23 25

R

GB

cut-off storage

leakage

and cut-off

current input

cut-off

control

19

C

R

CUT-OFF

COMPARATORS

leakage

storage

17

peak drive

limiting

storage

16

average

beam

15

current

BCOF

6-BIT D/A

hue control voltage

26

A45 to A40, A55 to A50, A65 to A60

AA5 to AA0

C-BUS

2

I

RECEIVER

27

28

SDA

SCL

C-bus

2

I

AND

AVERAGE

TIMING

GENERATOR

(H)

H + V

PULSE

DETECTOR

SC5

PEAK DRIVE

timing

pulses

BCOF

FSDIS2, FSON2,

2 x 8-BIT

CONTROL

CONVERTER

DELAYS

SWITCH-ON

1ST AND 2ND

BK

TDA4686

A05 to A00, A15 to A10, A25 to A20, A35 to A30

BREN

18

VFB

14

sandcastle

SANDCASTLE

pulse

3 x 6-BIT

LIMITING

BEAM CURRENT

4 x 6-BIT

FSDIS1, FSON1

NMEN

REGISTERS

101112

13

1

1

R

FSW

D/A

CONVERTERS

D/A

CONVERTERS

1

1

B

G

POINT

WHITE

ADJUST

B

R

G

ADJUST,

BLANKING 2,

BRIGHTNESS

MEASUREMENT
B

R

G

ADJUST

CONTRAST

B

R

G

BLANKING 1

FAST SIGNAL

SOURCE SWITCH,

B

R

G

NTSC

MATRIX

PAL/SECAM,

SATURATION

8

7

6

Y

−(R − Y)

−(B − Y)

PULSES

ADJUST

1
2

FSW

9

5

= 8 V

P

SUPPLY

V

handbook, full pagewidth

Fig.1 Block diagram.

C-bus data and

2

control signals

I

2

3

4

2

2

2

B

R

G

1997 Jun 23 4

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

PINNING

SYMBOL PIN DESCRIPTION

FSW
R

2

G

2

B

2

V

P

2

1 fast switch 2 input
2 red input 2
3 green input 2
4 blue input 2
5 supply voltage

−(B − Y) 6 colour difference input −(B − Y)

−(R − Y) 7 colour difference input −(R − Y)

Y 8 luminance input
GND 9 ground
R

1

G

1

B

1

FSW

1

10 red input 1
11 green input 1
12 blue input 1

13 fast switch 1 input
SC 14 sandcastle pulse input
BCL 15 average beam current limiting input

SYMBOL PIN DESCRIPTION

C

PDL

16 storage capacitor for peak drive

limiting

C

L

17 storage capacitor for leakage current
VFB 18 vertical flyback pulse input
CI 19 cut-off measurement input
B

O

C

B

G

O

C

G

R

O

C

R

20 blue output

21 blue cut-off storage capacitor

22 green output

23 green cut-off storage capacitor

24 red output

25 red cut-off storage capacitor
HUE 26 hue control output
SDA 27 I

2

C-bus serial data input;

acknowledge output

SCL 28 I

2

C-bus serial clock input

handbook, halfpage

Fig.2 Pin configuration (DIP-version).

FSW

R
G
B
V

−(B − Y)

−(R − Y)

GND

R
G
B

FSW

SC

2
2
2
2

P

Y

1
1
1
1

1
2
3
4
5
6
7
8

9
10
11
12
13
14

TDA4686

MED716

SCL

28

SDA

27

HUE

26

C

25

R

R

24

O

C

23

G

G

22

O

C

21

B

B

20

O

CI

19

VFB

18

C

17

L

C

16

PDL

BCL

15

V

−(B − Y)

−(R − Y)

GND

R
G

5

P

6
7

Y

8
9

10

1

11

1

B2G2R2FSW2SCL
4

3

2

1

28

TDA4686WP

12

13

14

15

1

1

B

SC

FSW

16

BCLCPDL

SDA
27

17

L

C

HUE
26

18

VFB

25
24
23
22
21
20
19

MED717

C

R

R

O

C

G

G

O

C

B

B

O

CI

Fig.3 Pin configuration (PLCC-version).

1997 Jun 23 5

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

2

I2C-BUS PROTOCOL

I

C-BUS RECEIVER (MICROCONTROLLER WRITE MODE)

Control

2

C-bus transmitter provides the data bytes to select

The I
and adjust the following functions and parameters:

• Brightness adjust

• Saturation adjust

• Contrast adjust

• DC output e.g. for hue control

• RGB gain adjust

• Peak drive limiting level adjust

• Selects either 3-level or 2-level (5 V) sandcastle pulse

• Enables cut-off control; enables output clamping

• Selects either PAL/SECAM or NTSC matrix

• Enables/disables synchronization of the execution of

I2C-bus commands with the vertical blanking interval

• Enables Y/CD, RGB1 or RGB2 input.

2

C-bus transmitter and data transfer

I

2

I

C-BUS SPECIFICATION

The I2C-bus is a bidirectional, two-wire, serial data bus for
intercommunication between ICs in an equipment.
The microcontroller transmits data to the I2C-bus receiver
in the TDA4686 over the serial data line SDA (pin 27)
synchronized by the serial clock line SCL (pin 28). Both
lines are normally connected to a positive voltage supply
through pull-up resistors. Data is transferred when the
SCL line is LOW. When SCL is HIGH the serial data line
SDA must be stable. A HIGH-to-LOW transition of the SDA
line when SCL is HIGH is defined as a START bit.
A LOW-to-HIGH transition of the SDA line when SCL is
HIGH is defined as a STOP bit.

Each transmission to the I2C-bus receiver consists of at
least three bytes following the START bit. Each byte is
acknowledged by an acknowledge bit immediately
following each byte. The first byte is the Module Address
(MAD) byte, also called slave address byte. This includes
the module address, 1000100 for the TDA4686.
The TDA4686 is a slave receiver (R/W = 0), therefore the
module address byte is 10001000 (88H; see also Fig.4).

The length of a data transmission is unrestricted, but the
module address and the correct subaddress must be
transmitted before the data byte(s). The order of data
transmission is shown in Figs 5 and 6.
Without auto-increment (BREN = 0 or 1) the module
address (MAD) byte is followed by a SubAddress (SAD)
byte and one data byte only (see Fig.5).

Each transmission must start with a START bit and end
with a STOP bit. The bus is busy after a START bit and is
only free again after a STOP bit has been transmitted.

1997 Jun 23 6

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

handbook, full pagewidth

handbook, full pagewidth

MSB LSB

01

module address

00100

Fig.4 The module address byte.

STOSAD

STOP

condition

START

condition

MADSTA

data byte

ACK0

R/W

MED710

MED697

Fig.5 Data transmission without auto-increment (BREN = 0 or 1).

handbook, full pagewidth

START

condition

MADSTA

SAD

data byte

Fig.6 Data transmission with auto-increment (BREN = 0).

1997 Jun 23 7

data bytes

STO

STOP

condition

MED698

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

AUTO-INCREMENT
The auto-increment format enables quick slave receiver

initialization by one transmission, when the I2C-bus control
bit BREN = 0 (see control register bits of Table 1).
If BREN = 1 auto-increment is not possible.

If the auto-increment format is selected, the MAD byte is
followed by a SAD byte and by the data bytes of
consecutive subaddresses (see Fig.6).

All subaddresses from 00H to 0FH are automatically
incremented, the subaddress counter wraps round from
0FH to 00H. Reserved subaddresses 07H, 08H, 09H,
0BH, 0EH and 0FH are treated as legal but have no effect.
Subaddresses outside the range 00H and 0FH are not
acknowledged by the device.

Subaddresses are stored in the TDA4686 to address the
following parameters and functions (see Table 1):

• Brightness adjust

• Saturation adjust

• Contrast adjust

• Hue control voltage

• RGB gain adjust

• Peak drive limiting adjust

• Control register functions.

ONTROL REGISTER 2

C
FSON2 (Fast Switch 2 ON).
FSDIS2 (Fast Switch 2 Disable).
FSON1 (Fast Switch 1 ON).
FSDIS1 (Fast Switch 1 Disable).
The RGB input signals are selected by FSON2 and

FSON1 or FSW2 and FSW1:

• FSON2 has priority over FSON1

• FSW2 has priority over FSW

• FSDIS1 and FSDIS2 disable FSW1 and FSW

1

2

(see Table 2).

BCOF (Black level Control Off):

0 = automatic cut-off control enabled
1 = automatic cut-off control disabled; RGB outputs are

clamped to fixed DC levels.

When the supply voltage has dropped below
approximately 6.0 V (usually occurs when the TV receiver
is switched on or the supply voltage is interrupted) all data
and function bits are set to 01H.

The data bytes D7 to D0 (see Table 1) provide the data of
the parameters and functions for video processing.

C

ONTROL REGISTER 1

NMEN (NTSC Matrix Enable):

0 = PAL/SECAM matrix
1 = NTSC matrix.

BREN (Buffer Register Enable):

0 = new data is executed as soon as it is received
1 = data is stored in buffer registers and is transferred to

the data registers during the next vertical blanking
interval.

The I2C-bus receiver does not accept any new data until
this data is transferred into the data registers.

SC5 (SandCastle 5 V):

0 = 3-level sandcastle pulse
1 = 2-level (5 V) sandcastle pulse.

1997 Jun 23 8

Philips Semiconductors Product specification

Video processor with automatic cut-off control TDA4686

Table 1 Subaddress (SAD) and data bytes; note 1

FUNCTION

Brightness 00 0 0 A05 A04 A03 A02 A01 A00
Saturation 01 0 0 A15 A14 A13 A12 A11 A10
Contrast 02 0 0 A25 A24 A23 A22 A21 A20
Hue control voltage 03 0 0 A35 A34 A33 A32 A31 A30
Red gain 04 0 0 A45 A44 A43 A42 A41 A40
Green gain 05 0 0 A55 A54 A53 A52 A51 A50
Blue gain 06 0 0 A65 A64 A63 A62 A61 A60
Reserved 07 0 0 X X X X X X
Reserved 08 0 0 X X X X X X
Reserved 09 0 0 X X X X X X
Peak drive limit 0A 0 0 AA5 AA4 AA3 AA2 AA1 AA0
Reserved 0B X X X X X X X X
Control register 1 0C SC5 X BREN X NMEN X X X
Control register 2 0D X X X BCOF FSDIS2 FSON2 FSDIS1 FSON1
Reserved 0E X X X X X X X X
Reserved 0F X X X X X X X X

Note

1. X = don’t care, but for software compatibility with other or future video ICs it is recommended to set all X to logic 0.

SAD

(HEX)

MSB LSB

D7 D6 D5 D4 D3 D2 D1 D0

1997 Jun 23 9