The TDA 6920 switches 7 video input sources to 5 outputs. Each output can be switched
to only one input, but one input can be switched to all outputs. The C-input may be
combined with one CVBS input as Y for Y+C (S-VHS) operation. Y+C operation is
selected by bus.
1.3Application
● Television sets
● Satellite receivers
● Video mixing desks
Semiconductor Group112.96
Page 2
1.4Pin Configuration
(top view)
P-DIP-18-5P-DSO-28-1
TDA 6920
Figure 1
Semiconductor Group2
Page 3
1.5Pin Definitions and Functions
Pin No.SymbolFunction
P-DIP-18-5P-DSO-28-1
–1GNDSignal and power supply ground
22IN1CVBS input 1
–3GNDSignal and power supply ground
34IN2CVBS input 2
–5GNDSignal and power supply ground
46IN3CVBS input 3
–7GNDSignal and power supply ground
58IN4CVBS input 4
TDA 6920
–9GNDSignal and power supply ground
610IN5CVBS input 5
–11
V
REF
Reference Voltage for external use
712IN6CVBS input 6
913GNDPower supply groung
814IN7CVBS input 7
1015SCLI
1116SDAI
2
C-Bus clock
2
C-Bus data
1217ADDRESSAddress selection
1318OUT5CVBS output 5
–19GNDSignal and power supply ground
1420OUT4CVBS output 4
–21GNDSignal and power supply ground
1522OUT3CVBS output 3
–23GNDSignal and power supply ground
1624OUT2CVBS output 2
–25GNDSignal and power supply ground
1726OUT1CVBS output 1
1827
V
CC
Positive power supply voltage
128CSeparate color adding input for input 1
Semiconductor Group3
Page 4
1.6Pin Description
TDA 6920
Overview
C (color input)
In 2, 5, 6, 7 (CVBS input)
In 2, 3, 4 (CVBS input)
SCL, Address
Semiconductor Group4
Page 5
TDA 6920
Overview
SDA
Out 1-5 (CVBS output)
V
(SO-28 only)
REF
Semiconductor Group5
Page 6
1.7Functional Block Diagram
TDA 6920
Figure 2
Block Diagram (P-DSO-28-1)
Semiconductor Group6
Page 7
TDA 6920
2Functional Description
The main function of the IC is to switch 7 input video sources to 5 outputs.
Each output can be switched to only one input.
It is possible to have the same input connected to several outputs.
3 of the inputs can be used as non-clamping-input, switching is controlled by bus.
The clamping function of the other 4 inputs can be overriden by external resistor divider.
The other 4 inputs can be switched to non-clamping mode with external R/C network.
2
All switching possibilities are controlled by the I
All outputs can be switched to low impedance off condition by the I
Driving 75 Ω load requires external transistors for best performance.
The recommended coupling capacitor at each input is 47 nF.
Each clamping input requires a 75 Ω (max. 500 Ω) termination resistor.
C Bus.
2
C Bus.
Operation without or with a termination resistor greater than 500 Ω causes malfunction
of the new high performance clamping circuit.
Unused inputs should be directly grounded.
6 × 8 bits are necessary to determine one complete configuration change.
(1 addressbyte, 5 databytes)
Minimum configuration change for 1 output needs 2 × 8 bit (1 addressbyte, 1 databyte).
Power on reset state: all 5 outputs switched to input 1, all inputs clamped, Y+C off.
● Address Selection (fast I
2
C Bus)
1st byte of transmisson (8 bit)
HexBinaryAddress Pin
MSBLSB
9610010110
V
(min. 3 V)
CC
9410010100GND
Semiconductor Group7
Page 8
TDA 6920
● Data Mode Selections (fast I
2
C Bus)
2nd byte of transmission (8 bit)
Output Selection (3 bit, bit 7 must always be 0)
b7 b6
1)
b5 b4 b3b2 b1 b0
1)
Selected Output
0X000XXX- not used
0X001XXXOUT1
0X010XXXOUT2
0X011XXXOUT3
0X100XXXOUT4
0X101XXXOUT5
0X110XXX- not used
0X111XXX- not used
1)
..X = don’t care
Input Selection Clamped (3 bit, bit 7 must always be 0)
b7 b6b5 b4 b3
1)
b2 b1 b0Selected Input
0XXXX000Output off condition
00XXX001IN1
00XXX010IN2
00XXX011IN3
00XXX100IN4
0XXXX101IN5
0XXXX110IN6
0XXXX111IN7
1)
..X = don’t care
Semiconductor Group8
Page 9
TDA 6920
● Data Mode Selections (fast I
2
C Bus) continued
2nd byte of transmission (8 bit)
Input Selection Non Clamped / Y+C (Y: always clamped. C: non clamped)
(3 bit, bit 7 must always be 0)
b7 b6b5 b4 b3
1)
b2 b1 b0Selected input
00XXX001in1, (Y+C) off
00XXX010in2, clamp on
00XXX011in3, clamp on
00XXX100in4, clamp on
01XXX001in1, (Y+C) on
01XXX010in2, clamp off
01XXX011in3, clamp off
01XXX100in4, clamp off
1)
X = don’t care (if only input operation mode change is requested, b5, b4
b3 should be 0, 0, 0: no output configuration is changed.)
● Bus Protocol (fast I
2
C Bus)
Programming Example: SDA sequence
serial data stream
address 96
start
condition
MSBLSB.....modeoutputinput
H
101001011000100011
data: output 5 connect to
input 1 (Y+C)
1st data: output 4 connect
to input 3 clamped
last data: output 1 connect
to input 4 not clamped
stop
condition
.....modeoutputinput.....modeoutputinput
011010010100110001
Semiconductor Group9
Page 10
TDA 6920
3Electrical Characteristics
3.1Absolute Maximum Ratings
ParameterSymbolLimit ValuesUnitTest Condition
min.max.
V
Supply voltage (
)V
CC
CC
014V
Reference voltage
(P-DSO-28-1 only)
Reference current
(
R
= 1 kΩ)
Lmin
Output voltage
Output current
(
R
= 500 Ω)
Lmin
Input voltage
Input voltage
SCL, SDA, address input
voltage
ESD-voltage all pins HBM
(
R = 1.5 kΩ, C = 100 pF)
Junction temperature
Storage temperature
Thermal resistance
(system - air)
V
REF
I
REF
V
OUT1 - OUT5
I
OUT1 - OUT5
V
C
V
IN1 - IN7
V
SDA, SCL,
Address
V
ESD
T
j
T
stg
R
th SA
05V
3.5mA
0V
CC
V
5mA
0V
0V
0V
CC
CC
CC
V
V
V
– 66kV
150°C
– 40125°C
75K/W
Note: Maximum ratings are absolute ratings; exceeding only one of these values may
cause irreversible damage to the integrated circuit.
Semiconductor Group10
Page 11
TDA 6920
3.2Operating Range
ParameterSymbolLimit ValuesUnitTest Condition
min.max.
Supply voltage
Absolute minimum supply
voltage (only usable with
reduced output signals of max.
2 Vpp)
Figure 6
Application Circuit P-DSO-28-1 (no clamping inputs with clamping overide)
Semiconductor Group17
Page 18
TDA 6920
Figure 7
Application Circuit (P-DIP-18-5)
Semiconductor Group18
Page 19
6Electrical Diagrams
Typical frequency response and crosstalk
(simulated) for P-DSO-28-1 package
TDA 6920
V
Conditions:
= 8.5 V, all outputs selected to one different input;
CC
response:the measured output has max. signal on the selected input;
crosstalk:the measured output has no signal on the selected input, another input has
max. signal
Semiconductor Group19
Page 20
7Package Outlines
P-DIP-18-5
(Plastic Dual in-line Package)
TDA 6920
P-DSO-28-1
(Plastic Dual Small Outline Package)
GPD05586
Sorts of Packing
Package outlines for tubes, trays etc. are contained in our
Data Book “Package Information”.
SMD = Surface Mounted Device
Semiconductor Group20
GPS05123
Dimensions in mm
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