1204 Layout.pm6
1
LT1204
4-Input Video Multiplexer
with 75MHz Current
Feedback Amplifier
S
FEATURE
D
U
ESCRIPTIO
The LT
1204 is a 4-input video multiplexer designed to
drive 75
cables and easily expand into larger routing
systems. Wide bandwidth, high slew rate, and low differ-
ential gain and phase make the LT1204 ideal for broadcast
quality signal routing. Channel separation and disable
isolation are greater than 90dB up to 10MHz. The channel-
to-channel output switching transient is only 40mV
P-P
,
with a 50ns duration, making the transition imperceptible
on high quality monitors.
A unique feature of the LT1204 is its ability to expand into
larger routing matrices. This is accomplished by a patent
pending circuit that bootstraps the feedback resistors in
the disable condition, raising the true output impedance of
the circuit. The effect of this feature is to eliminate cable
misterminations in large systems.
The large input and output signal levels supported by the
LT1204 when operated on
15V supplies make it ideal for
general purpose analog signal selection and multiplexing.
A shutdown feature reduces the supply current to 1.5mA.
All Hostile Crosstalk
Surface Mount PCB Measurements
FREQUENCY (MHz)
1
120
ALL HOSTILE CROSSTALK (dB) 100
80
60
40
10
100
1204 TA02
20
V
S
=
15V
V
IN 0
= GND
V
IN 1,2,3
= 0dBm
R
L
= 100
s
0.1dB Gain Flatness > 30MHz
s
Channel Separation at 10MHz: 90dB
s
40mV Switching Transient, Input Referred
s
3dB Bandwidth, A
V
= 2, R
L
= 150
: 75MHz
s
Channel-to-Channel Switching Time: 120ns
s
Easy to Expand for More Inputs
s
Large Input Range:
6V
s
0.04% Differential Gain, R
L
= 150
s
0.06
Differential Phase, R
L
= 150
s
High Slew Rate: 1000V/
s
s
Output Swing, R
L
= 400
:
13V
s
Wide Supply Range:
5V to
15V
U
S
A
O
PPLICATI
s
Broadcast Quality Video Multiplexing
s
Large Matrix Routing
s
Medical Imaging
s
Large Amplitude Signal Multiplexing
s
Programmable Gain Amplifiers
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
A
O
PPLICATI
TYPICAL
+
CFA
V
IN0
V
IN0
75
1
2
V
IN1
V
IN1
75
3
4
V
IN2
V
IN2
75
5
6
V
IN3
V
IN3
75
7
8
+1
+1
+1
+1
V
O
16
14
13
12
11
10
15
9
LOGIC
V
+
V
FB
S/D
ENABLE
A1
A0
15V
15V
R
F
1k
75
R
G
1k
V
OUT
8.2k
15V
LT1204
6.8k
GND
GND
GND
REF
1204 TA01
2
LT1204
A
U
G
W
A
W
U
W
A
R
BSOLUTE
XI
TI
S
Supply Voltage .....................................................
18V
Input Current (Pin 13) ....................................
15mA
+Input and Control/Logic Current (Note 1) ........
50mA
Output Short-Circuit Duration (Note 2) ......... Continuous
Specified Temperature Range (Note 3) ....... 0
C to 70
C
Operating Temperature Range ............... 40
C to 85
C
Storage Temperature Range ................ 65
C to 150
C
Junction Temperature (Note 4) ............................ 150
C
Lead Temperature (Soldering, 10 sec).................. 300
C
T
JMAX
= 150
C,
JA
= 70
C/W
ORDER PART
NUMBER
ORDER PART
NUMBER
LT1204CN*
1
2
3
4
5
6
7
8
TOP VIEW
N PACKAGE
16-LEAD PDIP
16
15
14
13
12
11
10
9
V
IN0
GND
V
IN1
GND
V
IN2
GND
V
IN3
REF
V
+
V
O
V
FB
SHDN
ENABLE
A1
A0
W
U
U
PACKAGE/ORDER I FOR ATIO
*See Note 3
*See Note 3
TOP VIEW
SW PACKAGE
16-LEAD PLASTIC SO
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
IN0
GND
V
IN1
GND
V
IN2
GND
V
IN3
REF
V
+
V
O
V
FB
SHDN
ENABLE
A1
A0
T
JMAX
= 150
C,
JA
= 90
C/W
Consult factory for Industrial and Military grade parts.
ELECTRICAL C
C
HARA TERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage
Any Positive Input, T
A
= 25
C
5
14
mV
q
16
mV
Offset Matching
Between Any Positive Input, V
S
=
15V
q
0.5
5
mV
Input Offset Voltage Drift
Any Positive Input
q
40
V/
C
I
IN
+
Positive Input Bias Current
Any Positive Input, T
A
= 25
C
3
8
A
q
10
A
I
IN
Negative Input Bias Current
T
A
= 25
C
20
100
A
q
150
A
e
n
Input Noise Voltage
f = 1kHz, R
F
= 1k, R
G
= 10
, R
S
= 0
7
nV/
Hz
+ i
n
Noninverting Input Noise Current Density
f = 1kHz
1.5
pA/
Hz
i
n
Inverting Input Noise Current Density
f = 1kHz
40
pA/
Hz
C
IN
Input Capacitance
Input Selected
3.0
pF
Input Deselected
3.5
pF
C
OUT
Output Capacitance
Disabled, Pin 11 Voltage = 0V
8
pF
R
IN
Positive Input Resistance, Any Positive Input
V
S
=
5V, V
IN
= 1.5V, 2V, T
A
= 25
C
5
20
M
V
S
=
15V, V
IN
=
5V
q
4
20
M
0
C
T
A
70
C,
5V
V
S
15V, V
CM
= 0V, Pin 8 grounded and pulse tested unless otherwise noted.
LT1204CSW*
3
LT1204
ELECTRICAL C
C
HARA TERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Voltage Range, Any Positive Input
V
S
=
5V, T
A
= 25
C
2.0
2.5
V
1.5
2.0
V
V
S
=
15V
q
5.0
6.0
V
V
S
=
15V, Pin 8 Voltage = 5V
q
3.75
4.0
V
CMRR
Common Mode Rejection Ratio
V
S
=
5V, V
CM
= 1.5V, 2V, T
A
= 25
C
48
55
dB
V
S
=
15V, V
CM
=
5V
q
48
58
dB
Negative Input Current
V
S
=
5V, V
CM
= 1.5V, 2V, T
A
= 25
C
0.05
1
A/V
Common Mode Rejection
V
S
=
15V, V
CM
=
5V
q
0.05
1
A/V
PSRR
Power Supply Rejection Ratio
V
S
=
4.5V to
15V
q
60
76
dB
Negative Input Current Power Supply Rejection
V
S
=
4.5V to
15V
q
0.5
5
A/V
A
VOL
Large-Signal Voltage Gain
V
S
=
15V, V
OUT
=
10V, R
L
= 1k
q
57
73
dB
V
S
=
5V, V
OUT
=
2V, R
L
= 150
q
57
66
dB
R
OL
Transresistance
V
S
=
15V, V
OUT
=
10V, R
L
= 1k
q
115
310
k
V
O
/
I
IN
V
S
=
5V, V
OUT
=
2V, R
L
= 150
q
115
210
k
V
OUT
Output Voltage Swing
V
S
=
15V, R
L
= 400
, T
A
= 25
C
12
13.5
V
q
10
V
V
S
=
5V, R
L
= 150
, T
A
= 25
C
3.0
3.7
V
q
2.5
V
I
OUT
Output Current
R
L
= 0
, T
A
= 25
C
35
55
125
mA
I
S
Supply Current (Note 5)
Pin 11 = 5V
q
19
24
mA
Pin 11 = 0V
q
19
24
mA
Pin 12 = 0V
q
1.5
3.5
mA
Disabled Output Resistance
V
S
=
15V, Pin 11 = 0V, V
O
=
5V,
R
F
= R
G
= 1k
q
14
25
k
V
S
=
15V, Pin 11 = 0V, V
O
=
5V,
R
F
= 2k, R
G
= 222
q
8
20
k
0
C
T
A
70
C,
5V
V
S
15V, V
CM
= 0V, Pin 8 grounded and pulse tested unless otherwise noted.
0
C
T
A
70
C, V
S
=
15V, R
F
= 2k, R
G
= 220
, R
L
= 400
unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IL
Input Low Voltage
Pins 9, 10, 11, 12
q
0.8
V
V
IH
Input High Voltage
Pins 9, 10, 11, 12
q
2
V
I
IL
Input Low Current
Pins 9, 10 Voltage = 0V
q
1.5
6
A
I
IH
Input High Current
Pins 9, 10 Voltage = 5V
q
10
150
nA
Enable Low Input Current
Pin 11 Voltage = 0V
q
4.5
15
A
Enable High Input Current
Pin 11 Voltage = 5V
q
200
300
A
I
SHDN
Shutdown Input Current
Pin 12 Voltage 0V
V
SHDN
5V
q
20
80
A
t
sel
Channel-to-Channel Select Time (Note 6)
Pin 8 Voltage = 5V, T
A
= 25
C
120
240
ns
t
dis
Disable Time (Note 7)
Pin 8 Voltage = 5V, T
A
= 25
C
40
100
ns
t
en
Enable Time (Note 8)
Pin 8 Voltage = 5V, T
A
= 25
C
110
200
ns
t
SHDN
Shutdown Assert or Release Time (Note 9)
Pin 8 Voltage = 5V, T
A
= 25
C
1.4
10
s
DIGITAL I PUT CHARACTERISTICS
U
4
LT1204
AC CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
t
r
, t
f
Small-Signal Rise and Fall Time
R
L
= 150
, V
OUT
=
125mV
5.6
ns
SR
Slew Rate (Note 10)
R
L
= 400
400
1000
V/
s
Channel Select Output Transient
All V
IN
= 0V, R
L
= 400
, Input Referred
40
mV
t
S
Settling Time
0.1%, V
OUT
= 10V, R
L
= 1k
70
ns
All Hostile Crosstalk (Note 11)
SO PCB #028, R
L
= 100
, R
S
= 10
92
dB
Disable Crosstalk (Note 11)
SO PCB #028, Pin 11 Voltage = 0V, R
L
= 100
, R
S
= 50
95
dB
Shutdown Crosstalk (Note 11)
SO PCB #028, Pin 12 Voltage = 0V, R
L
= 100
, R
S
= 50
92
dB
All Hostile Crosstalk (Note 11)
PDIP PCB #029, R
L
= 100
, R
S
= 10
76
dB
Disable Crosstalk (Note 11)
PDIP PCB #029, Pin 11 Voltage = 0V, R
L
= 100
, R
S
= 50
81
dB
Shutdown Crosstalk (Note 11)
PDIP PCB #029, Pin 12 Voltage = 0V, R
L
= 100
, R
S
= 50
76
dB
Differential Gain (Note 12)
V
S
=
15V, R
L
= 150
0.04
%
V
S
=
5V, R
L
= 150
0.04
%
Differential Phase (Note 12)
V
S
=
15V, R
L
= 150
0.06
DEG
V
S
=
5V, R
L
= 150
0.12
DEG
T
A
= 25
C, V
S
=
15V, R
F
= R
G
= 1k, unless otherwise noted.
The
q
denotes specifications which apply over the specified operating
temperature range.
Note 1: Analog and digital inputs (Pins 1, 3, 5, 7, 9, 10, 11 and 12) are
protected against ESD and overvoltage with internal SCRs. For inputs
<
6V the SCR will not fire, voltages above 6V will fire the SCRs and
the DC current should be limited to 50mA. To turn off the SCR the pin
voltage must be reduced to less than 2V or the current reduced to less
than 10mA.
Note 2: A heat sink may be required depending on the power supply
voltage.
Note 3: Commercial grade parts are designed to operate over the
temperature range of 40
C to 85
C but are neither tested nor
guaranteed beyond 0
C to 70
C. Industrial grade parts specified and
tested over 40
C to 85
C are available on special request. Consult
factory.
Note 4: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
LT1204CN: T
J
= T
A
+ (P
D
)(70
C/W)
LT1204CS: T
J
= T
A
+ (P
D
)(90
C/W)
Note 5: The supply current of the LT1204 has a negative temperature
coefficient. For more information see Typical Performance
Characteristics.
Note 6: Apply 0.5V DC to Pin 1 and measure the time for the
appearance of 5V at Pin 15 when Pin 9 goes from 5V to 0V. Pin 10
Voltage = 0V. Apply 0.5V DC to Pin 3 and measure the time for the
appearance of 5V at Pin 15 when Pin 9 goes from 0V to 5V. Pin 10
Voltage = 0V. Apply 0.5V DC to Pin 5 and measure the time for the
appearance of 5V at Pin 15 when Pin 9 goes from 5V to 0V. Pin 10
Voltage = 5V. Apply 0.5V DC to Pin 7 and measure the time for the
appearance of 5V at Pin 15 when Pin 9 goes from 0V to 5V. Pin 10
Voltage = 5V.
Note 7: Apply 0.5V DC to Pin 1 and measure the time for the
disappearance of 5V at Pin 15 when Pin 11 goes from 5V to 0V.
Pins 9 and 10 are at 0V.
Note 8: Apply 0.5V DC to Pin 1 and measure the time for the
appearance of 5V at Pin 15 when Pin 11 goes from 0V to 5V.
Pins 9 and 10 are at 0V. Above a 1MHz toggle rate, t
en
reduces.
Note 9: Apply 0.5V DC at Pin 1 and measure the time for the
appearance of 5V at Pin 15 when Pin 12 goes from 0V to 5V.
Pins 9 and 10 are at 0V. Then measure the time for the disappearance
of 5V DC to 500mV at Pin 15 when Pin 12 goes from 5V to 0V.
Note 10: Slew rate is measured at
5V on a
10V output signal while
operating on
15V supplies with R
F
= 2k, R
G
= 220
and R
L
= 400
.
Note 11: V
IN
= 0dBm (0.223V
RMS
) at 10MHz on any 3 inputs with the
4th input selected. For Disable crosstalk and Shutdown crosstalk all 4
inputs are driven simultaneously. A 6dB output attenuator is formed by
a 50
series output resistor and the 50
input impedance of the
HP4195A Network Analyzer. R
F
= R
G
= 1k.
Note 12: Differential Gain and Phase are measured using a Tektronix
TSG120 YC/NTSC signal generator and a Tektronix 1780R Video
Measurement Set. The resolution of this equipment is 0.1% and 0.1
.
Five identical MUXs were cascaded giving an effective resolution of
0.02% and 0.02
.
5
LT1204
Measurements taken from SO Demonstration Board #028.
TYPICAL AC PERFOR A CE
W U
SMALL SIGNAL
SMALL SIGNAL
SMALL SIGNAL
V
S
(V)
A
V
R
L
(
)
R
F
(
)
R
G
(
)
3dB BW (MHz)
0.1dB BW (MHz)
PEAKING (dB)
15
1
150
1.1k
None
88.5
48.3
0.1
1k
1.6k
None
95.6
65.8
0
12
1
150
976
None
82.6
49.1
0.1
1k
1.3k
None
90.2
63.6
0.1
5
1
150
665
None
65.5
43.6
0.1
1k
866
None
68.2
42.1
0.1
15
2
150
787
787
75.7
45.8
0
1k
887
887
82.2
61.3
0.1
12
2
150
750
750
71.9
45.0
0
1k
845
845
77.5
52.1
0
5V
2
150
590
590
58.0
32.4
0
1k
649
649
62.1
42.7
0.1
15
10
150
866
95.3
44.3
28.7
0.1
1k
1k
110
47.4
30.9
0.1
12
10
150
825
90.9
43.5
27.2
0
1k
931
100
46.3
32.1
0.1
5
10
150
665
73.2
37.2
22.1
0
1k
750
82.5
39.3
27.8
0.1
TRUTH TABLE
CHANNEL
A1
A0
ENABLE
SHUTDOWN
SELECTED
0
0
1
1
V
IN0
0
1
1
1
V
IN1
1
0
1
1
V
IN2
1
1
1
1
V
IN3
X
X
0
1
High Z Output
X
X
X
0
Off
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