LT1259/LT1260
Low Cost Dual and Triple
130MHz Current Feedback
Amplifiers with Shutdown
U
FEATURES
■
■
■
■
■
■
■
■
■
■
■
■
DESCRIPTIO
90MHz Bandwidth on ±5V
0.1dB Gain Flatness > 30MHz
Completely Off in Shutdown, 0µA Supply Current
High Slew Rate: 1600V/µs
Wide Supply Range: ±2V(4V) to ±15V(30V)
60mA Output Current
Low Supply Current: 5mA/Amplifier
Differential Gain: 0.016%
Differential Phase: 0.075°
Fast Turn-On Time: 100ns
Fast Turn-Off Time: 40ns
14-Pin and 16-Pin Narrow SO Packages
U
APPLICATIO S
■
■
■
■
When shut down, the LT1259/LT1260 amplifiers draw
zero supply current and their outputs become high
impedance. Only two LT1260s are required to make a
complete 2-input RGB MUX and cable driver. These
amplifiers turn on in only 100ns and turn off in 40ns,
making them ideal in spread spectrum and portable
equipment applications.
The LT1259/LT1260 amplifiers are manufactured on
Linear Technology’s proprietary complementary bipolar
process.
RGB Cable Drivers
Spread Spectrum Amplifiers
MUX Amplifiers
Composite Video Cable Drivers
Portable Equipment
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
■
The LT ®1259 contains two independent 130MHz current
feedback amplifiers, each with a shutdown pin. These
amplifiers are designed for excellent linearity while driving
cables and other low impedance loads. The LT1260 is a
triple version especially suited to RGB video applications.
These amplifiers operate on all supplies from single 5V to
±15V and draw only 5mA per amplifier when active.
TYPICAL APPLICATIO
2-Input Video MUX Cable Driver
A
+
RG
1.6k
B
EN A
75Ω
1/2 LT1259
–
75Ω
CABLE
RF
1.6k
VOUT
+
VIN B
RG
1.6k
EN B
CABLE OUTPUT
VIN A
CHANNEL
SELECT
Square Wave Response
75Ω
75Ω
1/2 LT1259
–
LT1259/60 • TA01
RF
1.6k
RL = 150Ω
f = 30MHz
LT1259/50 • TA02
1
LT1259/LT1260
W W
W
AXI U
U
ABSOLUTE
RATI GS
Supply Voltage ..................................................... ±18V
Input Current ..................................................... ±15mA
Output Short-Circuit Duration (Note 1) ......... Continuous
Specified Temperature Range (Note 2) ....... 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
U
U
W
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
–IN A
1
+IN A
2
GND
3
GND
4
11 GND
GND
5
10 V –
+IN B
6
–IN B
7
A
14 EN A
13 OUT A
12 V +
B
TOP VIEW
9
OUT B
8
EN B
LT1259CN
LT1259CS
LT1259IN
LT1259IS
N PACKAGE
S PACKAGE
14-LEAD PLASTIC DIP 14-LEAD PLASTIC SOIC
–IN R
1
+IN R
2
15 OUT R
GND
3
14 V +
–IN G
4
13 EN G
+IN G
5
12 OUT G
GND
6
11 V –
+IN B
7
–IN B
8
R
G
B
ORDER PART
NUMBER
16 EN R
LT1260CN
LT1260CS
LT1260IN
LT1260IS
10 OUT B
9
EN B
N PACKAGE
S PACKAGE
16-LEAD PLASTIC DIP 16-LEAD PLASTIC SOIC
TJMAX = 150°C, θJA = 70°C/W (N)
TJMAX = 150°C, θJA = 110°C/W (S)
TJMAX = 150°C, θJA = 70°C/W (N)
TJMAX = 150°C, θJA = 100°C/W (S)
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
0°C ≤ TA ≤ 70°C, each amplifier VCM = 0V, ±5V ≤ VS ≤ ±15V, EN pins = 0V, pulse tested, unless otherwise noted.
SYMBOL
VOS
PARAMETER
Input Offset Voltage
CONDITIONS
TA = 25°C
MIN
TYP
2
●
IIN+
Input Offset Voltage Drift
Noninverting Input Current
30
0.5
●
TA = 25°C
●
IIN–
Inverting Input Current
TA = 25°C
20
●
en
+ in
– in
RIN
Input Noise Voltage Density
Noninverting Input Noise Current Density
Inverting Input Noise Current Density
Input Resistance
CIN
Input Capacitance
COUT
VIN
Output Capacitance
Input Voltage Range
f = 1kHz, RF = 1k, RG = 10Ω, RS = 0Ω
f = 1kHz
f = 1kHz
VIN = ±13V, VS = ±15V
VIN = ±3V, VS = ±5V
Enabled
Disabled
Disabled
VS = ±15V, TA = 25°C
VS = ±5V, TA = 25°C
●
●
●
●
2
2
2
±13
±12
±3
±2
3.6
1.3
45
17
25
2
4
4.4
±13.5
±3.5
MAX
12
16
3
6
90
120
UNITS
mV
mV
µV/°C
µA
µA
µA
µA
nV/√Hz
pA/√Hz
pA/√Hz
MΩ
MΩ
pF
pF
pF
V
V
V
V
LT1259/LT1260
ELECTRICAL CHARACTERISTICS
0°C ≤ TA ≤ 70°C, each amplifier VCM = 0V, ±5V ≤ VS ≤ ±15V, EN pins = 0V, pulse tested, unless otherwise noted.
SYMBOL
VOUT
PARAMETER
Maximum Output Voltage Swing
CONDITIONS
VS = ±15V, RL = 1k
VS = ±5V, RL = 150Ω, TA = 25°C
CMRR
Common-Mode Rejection Ratio
VS = ±15V, VCM = ±13V, TA = 25°C
VS = ±15V, VCM = ±12V
VS = ±5V, VCM = ±3V, TA = 25°C
VS = ±5V, VCM = ±2V
VS = ±15V, VCM = ±13V, TA = 25°C
VS = ±15V, VCM = ±12V
VS = ±5V, VCM = ±3V, TA = 25°C
VS = ±5V, VCM = ±2V
VS = ±2V to ±15V, EN Pins at V –, TA = 25°C
VS = ±3V to ±15V, EN Pins at V –
VS = ±3V to ±15V, EN Pins at V –, TA = 25°C
VS = ±3V to ±15V, EN Pins at V –
VS = ±2V to ±15V, EN Pins at V –, TA = 25°C
VS = ±3V to ±15V, EN Pins at V –
VS = ±15V, VOUT = ±10V, RL = 1k
VS = ±5V, VOUT = ±2V, RL = 150Ω
VS = ±15V, VOUT = ±10V, RL = 1k
VS = ±5V, VOUT = ±2V, RL = 150Ω
RL = 0Ω, TA = 25°C
VS = ±15V, VOUT = 0V, TA = 25°C
●
●
Inverting Input Current
Common-Mode Rejection
PSRR
Power Supply Rejection Ratio
AV
Noninverting Input Current
Power Supply Rejection
Inverting Input Current
Power Supply Rejection
Large-Signal Voltage Gain
ROL
Transresistance, ∆VOUT/∆IIN–
IOUT
IS
Maximum Output Current
Supply Current per Amplifier
(Note 5)
●
●
TYP
±14.0
±3.7
63
3.5
4.5
●
●
60
60
15
0.1
●
●
●
57
57
120
100
30
72
69
300
200
60
5.0
●
Enable Pin Current
Slew Rate (Note 6)
Turn-On Delay Time (Note 7)
Turn-Off Delay Time (Note 7)
Small-Signal Rise and Fall Time
Propagation Delay
Small-Signal Overshoot
Settling Time
Differential Gain (Note 8)
Differential Phase (Note 8)
TA = 25°C
AV = 10, TA = 25°C
AV = 10, TA = 25°C
VS = ±12V, RF = RG = 1.5k, RL = 150Ω
VS = ±12V, RF = RG = 1.5k, RL = 150Ω
VS = ±12V, RF = RG = 1.5k, RL = 150Ω
0.1%, VOUT = 10V, RF = RG = 1.5k, RL = 1k
VS = ±12V, RF = RG = 1.5k, RL = 150Ω
VS = ±12V, RF = RG = 1.5k, RL = 150Ω
4.5
3
1
60
●
SR
tON
tOFF
tr, tf
tS
900
10
10
15
15
80
●
●
●
MAX
69
●
VS = ±5V, VOUT = 0V, TA = 25°C
VS = ±15V, EN Pin Voltage = 14.5V, RL = 150Ω ●
●
VS = ±15V, Sink 1µA From EN Pin
VS = ±15V, EN Pin Voltage = 0V, TA = 25°C
Disable Supply Current per Amplifier
MIN
±12.0
±3.0
±2.5
55
55
52
52
1600
100
40
4.2
4.7
5
75
0.016
0.075
65
75
5
5
7.5
7.9
6.7
16.7
2.7
200
300
400
150
UNITS
V
V
V
dB
dB
dB
dB
µA/V
µA/V
µA/V
µA/V
dB
dB
nA/V
nA/V
µA/V
µA/V
dB
dB
kΩ
kΩ
mA
mA
mA
mA
µA
µA
µA
µA
V/µs
ns
ns
ns
ns
%
ns
%
DEG
– 40°C ≤ TA ≤ 85°C, each amplifier VCM = 0V, ±5V ≤ VS ≤ ±15V, EN pins = 0V, pulse tested, unless otherwise noted.
SYMBOL
VOS
IIN+
IIN–
RIN
AV
IS
PARAMETER
Input Offset Voltage
Noninverting Input Current
Inverting Input Current
Input Resistance
Large-Signal Gain
Disable Supply Current per Amplifier
Enable Pin Current
CONDITIONS
MIN
●
●
●
VIN = ±3V, VS = ±5V
●
●
VS = ±15V, EN Pin Voltage = 14.5V, RL = 150Ω
VS = ±15V, EN Pin Voltage = 0V
●
●
TYP
MAX
18
7
130
1
55
19
350
UNITS
mV
µA
µA
MΩ
dB
µA
µA
3
LT1259/LT1260
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the specified operating
temperature range.
Note 1: A heat sink may be required depending on the power supply
voltage and how many amplifiers have their outputs short circuited.
Note 2: 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 3: Ground pins are not internally connected. For best
performance, connect to ground.
Note 4: TJ is calculated from the ambient temperature TA and the
power dissipation PD according to the following formulas:
LT1259CN/LT1259IN: TJ = TA + (PD • 70°C/W)
LT1259CS/LT1259IS: TJ = TA + (PD • 110°C/W)
LT1260CNLT1260IN/: TJ = TA + (PD • 70°C/W)
LT1260CS/LT1260IS: TJ = TA + (PD • 100°C/W)
Note 5: The supply current of the LT1259/LT1260 has a negative
temperature coefficient. See Typical Performance Characteristics.
Note 6: Slew rate is measured at ±5V on a ±10V output signal while
operating on ±15V supplies with RF = 1k, RG = 110Ω and RL = 1k.
Note 7: Turn-on delay time is measured while operating on ±5V
supplies with RF = 1k, RG = 110Ω and RL = 150Ω. The tON is measured
from control input to appearance of 0.5V at the output, for VIN = 0.1V.
Likewise, turn-off delay time is measured from control input to
appearance of 0.5V on the output for VIN = 0.1V.
Note 8: Differential gain and phase are measured using a Tektronix
TSG120YC/NTSC signal generator and a Tektronix 1780R Video
Measurement Set. The resolution of this equipment is 0.1% and 0.1°.
Six identical amplifier stages were cascaded giving an effective
resolution of 0.016% and 0.016°.
U W
TYPICAL AC PERFOR A CE
VS (V)
AV
RL (Ω)
RF (Ω)
RG (Ω)
SMALL SIGNAL
– 3dB BW (MHz)
SMALL SIGNAL
0.1dB BW (MHz)
SMALL SIGNAL
PEAKING (dB)
±12
2
150
1.5k
1.5k
130
53
0.1
±5
2
150
1.1k
1.1k
93
40
0
±12
10
150
1.1k
121
69
20
0.13
±5
10
150
825
90.9
61
16
0
U W
TYPICAL PERFOR A CE CHARACTERISTICS
±12V Frequency Response, AV = 10
±12V Frequency Response, AV = 2
12
9
–60
23
8
–80
7
–100
GAIN (dB)
GAIN
6
–120
5
4
VS = ±12V
RL = 150Ω
RF = RG = 1.5k
3
2
1
10
FREQUENCY (MHz)
100
LT1259/60 • TPC01
GAIN (dB)
24
0
PHASE
VS = ±12V
RL = 150Ω
RF = 1.1k
RG = 121Ω
22
–20
–40
–60
–80
21
–100
GAIN
20
–120
–140
19
–140
–160
18
–160
–180
17
–180
–200
16
–200
1
10
FREQUENCY (MHz)
100
LT1259/60 • TPC01
PHASE (DEG)
25
–40
PHASE
10
PHASE (DEG)
–20
11
4
26
0
LT1259/LT1260
U W
TYPICAL PERFOR A CE CHARACTERISTICS
±5V Frequency Response, AV = 2
±5V Frequency Response, AV = 10
12
0
26
0
11
–20
25
–20
10
–40
24
–60
23
GAIN (dB)
–100
GAIN
6
–120
5
VS = ±5V
RL = 150Ω
RF = RG = 1.1k
3
2
1
10
FREQUENCY (MHz)
–80
21
–100
GAIN
20
–120
19
–160
18
–180
17
–200
16
100
–140
VS = ±5V
RL = 150Ω
RF = 825Ω
RG = 90.9Ω
1
–160
–180
–200
10
FREQUENCY (MHz)
LT1259/60 • TPC03
Total Harmonic Distortion
vs Frequency
0.01
VO = 1VRMS
–40
–50
2ND
–60
3RD
100
1k
10k
FREQUENCY (Hz)
100k
30
20
10
100k
1M
10M
FREQUENCY (Hz)
100M
LTC1259/60 • TPC08
100
Output Impedance vs Frequency
100
–in
OUTPUT IMPEDANCE (Ω)
POSITIVE
40
10
FREQUENCY (MHz)
VS = ±15V
SPOT NOISE (nV/√Hz OR pA/√Hz)
NEGATIVE
50
AV = 2
LT12359/60 • TPC07
100
80
0
10k
1
100
Spot Noise Voltage and Current
vs Frequency
60
AV = 1
10
LT12359/60 • TPC06
Power Supply Rejection
vs Frequency
VS = ±15V
RL = 1OOΩ
RF = RG = 1k
AV = 10
0
10
FREQUENCY (MHz)
1
LT1259/60 • TPC05
70
15
5
–70
10
VS = ±15V
RL = 1k
RF = 2k
20
OUTPUT VOLTAGE (VP-P)
VO = 6VRMS
DISTORTION (dBc)
TOTAL HARMONIC DISTORTION (%)
25
VS = ±12V
VO = 2VP-P
AV = 10dB
RL = 100Ω
RF = 1.5k
–30
0.001
POWER SUPPLY REJECTION (dB)
Maximum Undistorted Output
vs Frequency
–20
VS = ±12V
RL = 400Ω
RF = RG = 1.5k
100
LT1259/60 • TPC04
2nd and 3rd Harmonic Distortion
vs Frequency
0.1
–60
22
–140
4
–40
PHASE
PHASE (DEG)
–80
7
PHASE (DEG)
8
GAIN (dB)
PHASE
9
10
en
RF = RG = 2k
10
1
+in
1
10
100
1k
10k
FREQUENCY (Hz)
100k
LT1259/60 • TPC09
0.1
10k
100k
1M
10M
FREQUENCY (Hz)
100M
LT1259/60 • TPC10
5
LT1259/LT1260
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Output Impedance in Shutdown
vs Frequency
Maximum Capacitive Load
vs Feedback Resistor
Supply Current vs Supply Voltage
1000
7
VS = ±15
AV = 1
RF = 1.5k
1
VS = ±5V
VS = ±15V
SUPPLY CURRENT (mA)
10
100
5
25°C
4
125°C
3
2
AV = 2
RL = 150Ω
PEAKING ≤ 5dB
0.1
100k
1M
10M
FREQUENCY (Hz)
10
100M
1
2
3
4
5
FEEDBACK RESISTOR (kΩ)
LT1259/60 • TPC11
0
6
0
COMMON-MODE RANGE (V)
–0.5
0.5
V + = 2V TO 18V
–1.0
–1.5
–2.0
2.0
1.5
1.0
V – = –2V TO –18V
0.5
V–
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
6
8 10 12 14
SUPPLY VOLTAGE (±V)
V–
–50 –25
Settling Time to 10mV
vs Output Step
50
25
0
75
TEMPERATURE (°C)
100
125
60
50
40
– 50 – 25
0
25 50 75 100 125 150
TEMPERATURE (°C)
LT1259/60 • TPC15
Small-Signal Rise Time
10
VS = ±12V
RF = 1.5k
8
OUTPUT STEP (V)
6
4
2
NONINVERTING
0
INVERTING
–2
–4
–6
–8
–10
0
100 200 300 400 500 600 700 800
SETTLING TIME (ns)
LT1259/60 • TPC17
6
18
70
LT1259/60 • TPC16
LT1259/60 • TPC14
16
80
OUTPUT SHORT-CIRCUIT CURRENT (mA)
RL = ∞
±2V ≤ VS ≤ ±18V
1.0
4
Output Short-Circuit Current
vs Junction Temperature
V+
–1.0
2
LT1259/60 • TPC13
Input Common-Mode Limit
vs Temperature
V+
OUTPUT SATURATION VOLTAGE (V)
1
LT1259/60 • TPC12
Output Saturation Voltage
vs Temperature
–0.5
–55°C
6
LOAD CAPACITANCE (pF)
OUTPUT IMPEDANCE (kΩ)
100
VS = ±15V
AV = 2
RF = RG = 1.6k
RL = 150Ω
LT1259/60 G19
LT1259/LT1260
W
W
SI PLIFIED SCHE ATIC , each amplifier
+IN
V+
–IN
OUT
EN
V–
LT1259/60 • SS
U
W
U U
APPLICATIO S I FOR ATIO
Feedback Resistor Selection
The small-signal bandwidth of the LT1259/ LT1260 are set
by the external feedback resistors and the internal junction
capacitors. As a result, the bandwidth is a function of the
supply voltage, the value of the feedback resistor, the
closed-loop gain and the load resistor. The LT1259/LT1260
have been optimized for ±5V supply operation and have a
– 3dB bandwidth of 90MHz. See resistor selection guide in
Typical AC Performance table.
Capacitance on the Inverting Input
Current feedback amplifiers require resistive feedback
from the output to the inverting input for stable operation.
Take care to minimize the stray capacitance between the
output and the inverting input. Capacitance on the inverting input to ground will cause peaking in the frequency
response (and overshoot in the transient response). See
the section on Demo Board Information.
Capacitive Loads
The LT1259/LT1260 can drive capacitive loads directly
when the proper value of feedback resistor is used. The
graph of Maximum Capacitive Load vs Feedback Resistor
should be used to select the appropriate value. The value
shown is for ≤ 5dB peaking when driving a 150Ω load at a
gain of 2. This is a worst case condition. The amplifier is
more stable at higher gains. Alternatively, a small resistor
(10Ω to 20Ω) can be put in series with the output to isolate
the capacitive load from the amplifier output. This has the
advantage that the amplifier bandwidth is only reduced
when the capacitive load is present. The disadvantage is
that the gain is a function of the load resistance.
Power Supplies
The LT1259/LT1260 will operate from single or split
supplies from ±2V (4V total) to ±15V (30V total). It is not
necessary to use equal value split supplies, however the
offset voltage and inverting input bias current will change.
The offset voltage changes about 500µV per volt of
supply mismatch. The inverting bias current can change
as much as 5µA per volt of supply mismatch though
typically, the change is about 0.1µA per volt.
Slew Rate
The slew rate of a current feedback amplifier is not
independent of the amplifier gain configuration the way
slew rate is in a traditional op amp. This is because both the
input stage and the output stage have slew rate limitations.
In the inverting mode, and for higher gains in the noninverting mode, the signal amplitude between the input pins
is small and the overall slew rate is that of the output stage.
For gains less than ten in the noninverting mode, the
overall slew rate is limited by the input stage.
7
LT1259/LT1260
U
W
U U
APPLICATIO S I FOR ATIO
The input slew rate of the LT1259/LT1260 is approximately 270V/µs and is set by internal currents and capacitances. The output slew rate is set by the value of the
feedback resistors and internal capacitances. At a gain of
10 with at 1k feedback resistor and ±15V supplies, the
output slew rate is typically 1600V/µs. Larger feedback
resistors will reduce the slew rate as will lower supply
voltages, similar to the way the bandwidth is reduced.
The graph of Maximum Undistorted Output vs Frequency
relates the slew rate limitations to sinusoidal input for
various gains.
looks like a 4.4pF capacitor in parallel with a 75k resistor,
excluding feedback resistor effects. These amplifiers are
designed to operate with open drain logic: the EN pins have
internal pullups and the amplifiers draw zero current when
these pins are high. To activate an amplifier, its EN pin is
pulled to ground (or at least 2V below the positive supply).
The enable pin current is approximately 60µA when
activated. Input referred switching transients with no
input signal applied are only 35mV positive and 80mV
negative with RL = 100Ω.
Output Switching Transient
Large-Signal Transient Response, AV = 2
EN
OUTPUT
VS = ±5V
VIN = 0V
VS = ±15V
RF = RG = 1.6k
RL = 400Ω
LT1259/LT1260 • AI01
Large-Signal Transient Response, AV = 10
LT1259/LT1260 • AI03
RF = RG = 1.6k
RL = 100Ω
The enable/disable times are very fast when driven from
standard 5V logic. The amplifier enables in about 100ns
(50% point to 50% point) while operating on ±5V supplies. Likewise the disable time is approximately 40ns
(50% point to 50% point) or 75ns to 90% of the final
value. The output decay time is set by the output capacitance and load resistor.
Amplifier Enable Time, AV = 10
OUTPUT
VS = ±15V
RF = 1k
RG = 110Ω
RL = 400Ω
EN
LT1259/LT1260 • AI02
Enable/Disable
The LT1259/LT1260 amplifiers have a unique high impedance, zero supply current mode which is controlled by
independent EN pins. When disabled, an amplifier output
8
VS = ±5V
VIN = 0.1V
RF = 1k
RG = 110Ω
RL = 150Ω
LT1259/LT1260 • AI04
LT1259/LT1260
U
W
U U
APPLICATIO S I FOR ATIO
Amplifier Disable Time, AV = 10
Amplifier Enable/Disable Time, AV = 2
EN
EN
OUTPUT
OUTPUT
VS = ±5V
VIN = 0.1V
RF = 1k
RG = 110Ω
VS = ±5V
VIN = 2VPP at 2MHz
LT1259/LT1260 • AI05
RL = 150Ω
Differential Input Signal Swing
The differential input swing is limited to about ±6V by an
ESD protection device connected between the inputs. In
normal operation, the differential voltage between the
RF = RG = 1.6k
RL = 100Ω
LT1259/LT1260 • AI06
input pins is small, so this clamp has no effect. In the
disabled mode however, the differential swing can be the
same as the input swing, and the clamp voltage will set the
maximum allowable input voltage.
U
TYPICAL APPLICATIO S
2-Input Video MUX Cable Driver
The application on the first page shows a low cost, 2input video MUX cable driver. The scope photo displays
the cable output of a 30MHz square wave driving 150Ω.
In this circuit the active amplifier is loaded by RF and RG
of the disabled amplifier, but in this case it only causes a
1.2% gain error. The gain error can be eliminated by
2-Input Video MUX Switching Response
EN A
EN B
VS = ±5V
VIN A = VIN 2 = 2VPP at 2MHz
RF = RG = 1.6k
RL = 100Ω
configuring each amplifier as a unity-gain follower. The
switching time between channels is 100ns when both
EN A and EN B are driven.
2-Input RGB MUX Cable Driver Demonstration Board
A complete 2-input RGB MUX has been fabricated on PC
Demo Board #039A. The board incorporates two LT1260s
with outputs summed through 75Ω back termination
resistors as shown in the schematic. There are several
things to note about Demo Board #039A:
1. The feedback resistors of the disabled LT1260 load
the enabled amplifier and cause a small (1% to 2%)
gain error depending on the values of RF and RG.
Configure the amplifiers as unity-gain followers to
eliminate this error.
2. The feedback node has minimum trace length connecting RF and RG to minimize stray capacitance.
3. Ground plane is pulled away from RF and RG on both
sides of the board to minimize stray capacitance.
LT1259/LT1260 • TA03
9
LT1259/LT1260
U
TYPICAL APPLICATIO S
RGB Demo Board All Hostile Crosstalk
0
ALL HOSTILE CROSSTALK (dB)
4. Capacitors C1 and C6 are optional and only needed to
reduce overshoot when EN 1 or EN 2 are activated with
a long inductive ground wire.
5. The R, G and B amplifiers have slightly different
frequency responses due to different output trace
routing to RF (between pins 3 and 4). All amplifiers
have slightly less bandwidth in PCB #039 than when
measured alone as shown in the Typical AC Performance table.
6. Part-to-part variation can change the peaking by
±0.25dB.
VS = ±12V
RL = 100Ω
RF = RG = 1.6k
RS = 10Ω
–20
–40
G
–60
B
R
–80
–100
10
FREQUENCY (MHz)
1
100
LT1259/60 • TA06
RGB Demo Board Gain vs Frequency
4
VS = ±12V
RL = 150Ω
RF = RG = 1.6k
GAIN (dB)
2
P-DIP PC Board #039
R
0
G
EN2
B
R1
–2
EN1
V+
V–
U1
R1
R2
R13
–4
G1
–6
1
10
FREQUENCY (MHz)
100
GND
C1
R3
R4
R14
C2
R
C3
R15
R5
R6
LT1259/60 • TA04
C4
B1
C6
RGB Demo Board Gain vs Frequency
4
R2
VS = ±5V
RL = 150Ω
RF = RG = 1.1k
2
GAIN (dB)
R, B
G2
G
U2
C5
R16
C7
B
R17
C8
R18
R11
R12
(408) 432-1900
LT1260 RGB AMPLIFIER
DEMONSTRATION BOARD
–2
B2
–4
LT1259/60 • TA07
–6
1
10
FREQUENCY (MHz)
100
LT1259/60 • TA05
10
R7
R8
R9
R10
0
G
LT1259/LT1260
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
N Package
14-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.130 ± 0.005
(3.302 ± 0.127)
0.300 – 0.325
(7.620 – 8.255)
0.045 – 0.065
(1.143 – 1.651)
0.015
(0.380)
MIN
+0.025
0.325 –0.015
0.005
(0.125)
MIN
0.100 ± 0.010
(2.540 ± 0.254)
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
(
14
13
12
11
10
9
8
1
2
3
4
5
6
7
0.255 ± 0.015*
0.065 (6.477 ± 0.381)
(1.651)
TYP
0.009 – 0.015
(0.229 – 0.381)
+0.635
8.255
–0.381
0.770*
(19.558)
MAX
)
0.018 ± 0.003
(0.457 ± 0.076)
0.125
(3.175)
MIN
N14 0695
N Package
16-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.130 ± 0.005
(3.302 ± 0.127)
0.300 – 0.325
(7.620 – 8.255)
0.009 – 0.015
(0.229 – 0.381)
(
+0.635
–0.381
0.045 – 0.065
(1.143 – 1.651)
0.015
(0.381)
MIN
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
0.255 ± 0.015*
0.065 (6.477 ± 0.381)
(1.651)
TYP
+0.025
0.325 –0.015
8.255
0.770*
(19.558)
MAX
)
0.005
(0.127)
MIN
0.100 ± 0.010
(2.540 ± 0.254)
0.125
(3.175)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
N16 0695
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
S Package
14-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.337 – 0.344*
(8.560 – 8.738)
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
13
14
0.004 – 0.010
(0.101 – 0.254)
12
11
10
8
9
0° – 8° TYP
0.014 – 0.019
(0.355 – 0.483)
0.016 – 0.050
0.406 – 1.270
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
0.228 – 0.244
(5.791 – 6.197)
0.050
(1.270)
TYP
0.150 – 0.157**
(3.810 – 3.988)
1
3
2
5
4
S14 0695
7
6
S Package
16-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.386 – 0.394*
(9.804 – 10.008)
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
16
15
14
13
12
11
10
9
0° – 8° TYP
0.016 – 0.050
0.406 – 1.270
0.014 – 0.019
(0.355 – 0.483)
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
0.050
(1.270)
TYP
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
2
3
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
4
5
6
7
8
S16 0695
11
LT1259/LT1260
U
TYPICAL APPLICATIO
Demonstration PC Board Schematic #039
C1*
0.01µF
R1
EN 1 EN 2
V+
V–
GND
R2
1
R
2
R1
+
3
R3
LT1260
4
R4
G
+
R6
C2
0.1µF R14
75Ω
12
VOUT GREEN
10
+
B
8
–
C3
0.1µF R15
75Ω
9
VOUT BLUE
R5
C4
4.7µF
+
C6*
0.01µF
R7
1
2
3
R9
4
5
G2
R10
R12
C5
4.7µF
16
–
R
+
LT1260
8
R16
75Ω
15
14
C7
0.1µF
13
–
G
+
R17
75Ω
12
11
6
7
B2
+
R8
R2
VOUT RED
14
11
6
7
B1
R13
75Ω
15
13
–
5
G1
16
–
C8
0.1µF
10
+
B
–
9
R18
75Ω
LT1259/60 • TA08
R11
*OPTIONAL
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1203/LT1205
150MHz Video Multiplexers
2:1 and Dual 2:1 MUXes with 25ns Switch Time
LT1204
4-Input Video MUX with Current Feedback Amplifier
Cascadable Enable 64:1 Multiplexing
LT1227
140MHz Current Feedback Amplifier
1100V/µs Slew Rate, Shutdown Mode
LT1252/LT1253/LT1254
Low Cost Video Amplifiers
Single, Dual and Quad Current Feedback Amplifiers
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417 ● (408) 432-1900
FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com
125960fas, sn125960 LT/TP 1197 REV A 4K • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1993