LT1204
4-Input Video Multiplexer
with 75MHz Current
Feedback Amplifier
DESCRIPTIO
The LT
®
1204 is a 4-input video multiplexer designed to
drive 75Ω 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
FEATURES
s
s
s
s
s
s
s
s
s
s
s
s
0.1dB Gain Flatness > 30MHz
Channel Separation at 10MHz: 90dB
40mV Switching Transient, Input Referred
– 3dB Bandwidth, A
V
= 2, R
L
= 150Ω: 75MHz
Channel-to-Channel Switching Time: 120ns
Easy to Expand for More Inputs
Large Input Range:
±
6V
0.04% Differential Gain, R
L
= 150Ω
0.06° Differential Phase, R
L
= 150Ω
High Slew Rate: 1000V/µs
Output Swing, R
L
= 400Ω:
±13V
Wide Supply Range:
±5V
to
±15V
APPLICATI
s
s
s
s
s
S
Broadcast Quality Video Multiplexing
Large Matrix Routing
Medical Imaging
Large Amplitude Signal Multiplexing
Programmable Gain Amplifiers
TYPICAL APPLICATI
V
IN0
75Ω
2
3
75Ω
4
5
75Ω
6
7
75Ω
8
REF
–15V
6.8k
8.2k
GND
V
IN3
+1
GND
V
IN2
+1
GND
V
IN1
+1
1
V
IN0
+1
V
+
16
15V
75Ω
V
OUT
–20
+
CFA
V
O
15
V
–
14
ALL HOSTILE CROSSTALK (dB)
V
IN1
–
–15V
R
F
1k
–40
FB 13
S/D 12
ENABLE 11
LOGIC
A1 10
A0 9
R
G
1k
–60
V
IN2
–80
–100
V
IN3
–120
LT1204
1204 TA01
U
UO
UO
All Hostile Crosstalk
Surface Mount PCB Measurements
V
S
=
±15V
V
IN 0
= GND
V
IN 1,2,3
= 0dBm
R
L
= 100Ω
1
10
FREQUENCY (MHz)
100
1204 TA02
1
LT1204
ABSOLUTE
AXI U
RATI GS
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
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
PACKAGE/ORDER I FOR ATIO
TOP VIEW
V
IN0
GND
V
IN1
GND
V
IN2
GND
V
IN3
REF
1
2
3
4
5
6
7
8
N PACKAGE
16-LEAD PDIP
16 V
+
15 V
O
14 V
–
13 FB
12 SHDN
11 ENABLE
10 A1
9
A0
ORDER PART
NUMBER
LT1204CN*
T
JMAX
= 150°C,
θ
JA
= 70°C/W
*See Note 3
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
0°C
≤
T
A
≤
70°C,
±5V ≤
V
S
≤ ±15V,
V
CM
= 0V, Pin 8 grounded and pulse tested unless otherwise noted.
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
Offset Matching
Input Offset Voltage Drift
I
IN+
I
IN–
e
n
+ i
n
– i
n
C
IN
C
OUT
R
IN
Positive Input Bias Current
Negative Input Bias Current
Input Noise Voltage
Noninverting Input Noise Current Density
Inverting Input Noise Current Density
Input Capacitance
Output Capacitance
Positive Input Resistance, Any Positive Input
CONDITIONS
Any Positive Input, T
A
= 25°C
q
Between Any Positive Input, V
S
=
±15V
Any Positive Input
Any Positive Input, T
A
= 25°C
T
A
= 25°C
q
f = 1kHz, R
F
= 1k, R
G
= 10Ω, R
S
= 0Ω
f = 1kHz
f = 1kHz
Input Selected
Input Deselected
Disabled, Pin 11 Voltage = 0V
V
S
=
±5V,
V
IN
= – 1.5V, 2V, T
A
= 25°C
V
S
=
±15V,
V
IN
=
±5V
q
2
U
U
W
W W
U
W
TOP VIEW
V
IN0
1
GND 2
V
IN1
3
GND 4
V
IN2
5
GND 6
V
IN3
7
REF 8
SW PACKAGE
16-LEAD PLASTIC SO
16 V
+
ORDER PART
NUMBER
LT1204CSW*
15 V
O
14 V
–
13 FB
12 SHDN
11 ENABLE
10 A1
9
A0
T
JMAX
= 150°C,
θ
JA
= 90°C/W
*See Note 3
MIN
TYP
5
MAX
14
16
5
8
10
±100
±150
UNITS
mV
mV
mV
µV/°C
µA
µA
µA
µA
nV/√Hz
pA/√Hz
pA/√Hz
pF
pF
pF
MΩ
MΩ
q
q
q
0.5
40
3
±20
7
1.5
40
3.0
3.5
8
5
4
20
20
LT1204
ELECTRICAL CHARACTERISTICS
0°C
≤
T
A
≤
70°C,
±5V ≤
V
S
≤ ±15V,
V
CM
= 0V, Pin 8 grounded and pulse tested unless otherwise noted.
SYMBOL
PARAMETER
Input Voltage Range, Any Positive Input
CONDITIONS
V
S
=
±5V,
T
A
= 25°C
V
S
=
±15V
V
S
=
±15V,
Pin 8 Voltage = – 5V
CMRR
Common Mode Rejection Ratio
Negative Input Current
Common Mode Rejection
PSRR
A
VOL
R
OL
V
OUT
Power Supply Rejection Ratio
Negative Input Current Power Supply Rejection
Large-Signal Voltage Gain
Transresistance
∆V
O
/∆I
IN–
Output Voltage Swing
V
S
=
±5V,
V
CM
= – 1.5V, 2V, T
A
= 25°C
V
S
=
±15V,
V
CM
=
±5V
V
S
=
±5V,
V
CM
= – 1.5V, 2V, T
A
= 25°C
V
S
=
±15V,
V
CM
=
±5V
V
S
=
±4.5V
to
±15V
V
S
=
±4.5V
to
±15V
V
S
=
±15V,
V
OUT
=
±10V,
R
L
= 1k
V
S
=
±5V,
V
OUT
=
±2V,
R
L
= 150Ω
V
S
=
±15V,
V
OUT
=
±10V,
R
L
= 1k
V
S
=
±5V,
V
OUT
=
±2V,
R
L
= 150Ω
V
S
=
±15V,
R
L
= 400Ω, T
A
= 25°C
q
q
q
q
q
q
q
q
q
q
q
MIN
2.0
– 1.5
±5.0
3.75
48
48
TYP
2.5
– 2.0
±6.0
4.0
55
58
0.05
0.05
MAX
UNITS
V
V
V
V
dB
dB
1
1
5
µA/V
µA/V
dB
µA/V
dB
dB
kΩ
kΩ
V
V
V
V
60
57
57
115
115
±12
±10
±3.0
±2.5
35
76
0.5
73
66
310
210
±13.5
±3.7
55
19
19
1.5
125
24
24
3.5
V
S
=
±5V,
R
L
= 150Ω, T
A
= 25°C
q
I
OUT
I
S
Output Current
Supply Current (Note 5)
R
L
= 0Ω, T
A
= 25°C
Pin 11 = 5V
Pin 11 = 0V
Pin 12 = 0V
V
S
=
±15V,
Pin 11 = 0V, V
O
=
±5V,
R
F
= R
G
= 1k
V
S
=
±15V,
Pin 11 = 0V, V
O
=
±5V,
R
F
= 2k, R
G
= 222Ω
q
q
q
q
q
mA
mA
mA
mA
kΩ
kΩ
Disabled Output Resistance
14
8
25
20
DIGITAL I PUT CHARACTERISTICS
SYMBOL
V
IL
V
IH
I
IL
I
IH
PARAMETER
Input Low Voltage
Input High Voltage
Input Low Current
Input High Current
Enable Low Input Current
Enable High Input Current
I
SHDN
t
sel
t
dis
t
en
t
SHDN
Shutdown Input Current
Channel-to-Channel Select Time (Note 6)
Disable Time (Note 7)
Enable Time (Note 8)
Shutdown Assert or Release Time (Note 9)
0°C
≤
T
A
≤
70°C, V
S
=
±15V,
R
F
= 2k, R
G
= 220Ω, R
L
= 400Ω unless otherwise noted.
CONDITIONS
Pins 9, 10, 11, 12
Pins 9, 10, 11, 12
Pins 9, 10 Voltage = 0V
Pins 9, 10 Voltage = 5V
Pin 11 Voltage = 0V
Pin 11 Voltage = 5V
Pin 12 Voltage 0V
≤
V
SHDN
≤
5V
Pin 8 Voltage = – 5V, T
A
= 25°C
Pin 8 Voltage = – 5V, T
A
= 25°C
Pin 8 Voltage = – 5V, T
A
= 25°C
Pin 8 Voltage = – 5V, T
A
= 25°C
q
q
q
q
q
q
q
U
MIN
2
TYP
MAX
0.8
UNITS
V
V
µA
nA
µA
µA
µA
ns
ns
ns
µs
1.5
10
4.5
200
20
120
40
110
1.4
6
150
15
300
80
240
100
200
10
3
LT1204
AC CHARACTERISTICS
SYMBOL
t
r
, t
f
SR
t
S
PARAMETER
Small-Signal Rise and Fall Time
Slew Rate (Note 10)
Channel Select Output Transient
Settling Time
All Hostile Crosstalk (Note 11)
Disable Crosstalk (Note 11)
Shutdown Crosstalk (Note 11)
All Hostile Crosstalk (Note 11)
Disable Crosstalk (Note 11)
Shutdown Crosstalk (Note 11)
Differential Gain (Note 12)
Differential Phase (Note 12)
T
A
= 25°C, V
S
=
±15V,
R
F
= R
G
= 1k, unless otherwise noted.
CONDITIONS
R
L
= 150Ω, V
OUT
=
±125mV
R
L
= 400Ω
All V
IN
= 0V, R
L
= 400Ω, Input Referred
0.1%, V
OUT
= 10V, R
L
= 1k
SO PCB #028, R
L
= 100Ω, R
S
= 10Ω
SO PCB #028, Pin 11 Voltage = 0V, R
L
= 100Ω, R
S
= 50Ω
SO PCB #028, Pin 12 Voltage = 0V, R
L
= 100Ω, R
S
= 50Ω
PDIP PCB #029, R
L
= 100Ω, R
S
= 10Ω
PDIP PCB #029, Pin 11 Voltage = 0V, R
L
= 100Ω, R
S
= 50Ω
PDIP PCB #029, Pin 12 Voltage = 0V, R
L
= 100Ω, R
S
= 50Ω
V
S
=
±15V,
R
L
= 150Ω
V
S
=
±5V,
R
L
= 150Ω
V
S
=
±15V,
R
L
= 150Ω
V
S
=
±5V,
R
L
= 150Ω
400
MIN
TYP
5.6
1000
40
70
92
95
92
76
81
76
0.04
0.04
0.06
0.12
MAX
UNITS
ns
V/µs
mV
ns
dB
dB
dB
dB
dB
dB
%
%
DEG
DEG
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
= 220Ω and R
L
= 400Ω.
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 50Ω series output resistor and the 50Ω 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°.
4
LT1204
TYPICAL AC PERFOR A CE
V
S
(V)
±15
±12
±5
±15
±12
±5V
±15
±12
±5
A
V
1
1
1
2
2
2
10
10
10
R
L
(Ω)
150
1k
150
1k
150
1k
150
1k
150
1k
150
1k
150
1k
150
1k
150
1k
R
F
(Ω)
1.1k
1.6k
976
1.3k
665
866
787
887
750
845
590
649
866
1k
825
931
665
750
TRUTH TABLE
A1
0
0
1
1
X
X
A0
0
1
0
1
X
X
ENABLE
1
1
1
1
0
X
SHUTDOWN
1
1
1
1
1
0
CHANNEL
SELECTED
V
IN0
V
IN1
V
IN2
V
IN3
High Z Output
Off
U W
Measurements taken from SO Demonstration Board #028.
R
G
(Ω)
None
None
None
None
None
None
787
887
750
845
590
649
95.3
110
90.9
100
73.2
82.5
SMALL SIGNAL
– 3dB BW (MHz)
88.5
95.6
82.6
90.2
65.5
68.2
75.7
82.2
71.9
77.5
58.0
62.1
44.3
47.4
43.5
46.3
37.2
39.3
SMALL SIGNAL
0.1dB BW (MHz)
48.3
65.8
49.1
63.6
43.6
42.1
45.8
61.3
45.0
52.1
32.4
42.7
28.7
30.9
27.2
32.1
22.1
27.8
SMALL SIGNAL
PEAKING (dB)
0.1
0
0.1
0.1
0.1
0.1
0
0.1
0
0
0
0.1
0.1
0.1
0
0.1
0
0.1
5
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