ETC LT1397CGN

LT1395/LT1396/LT1397
Single/Dual/Quad 400MHz
Current Feedback Amplifier
U
FEATURES
■
■
■
■
■
■
■
■
DESCRIPTIO
400MHz Bandwidth on ± 5V (AV = 1)
350MHz Bandwidth on ± 5V (AV = 2, –1)
0.1dB Gain Flatness: 100MHz (AV = 1, 2 and –1)
High Slew Rate: 800V/µs
Wide Supply Range: ±2V(4V) to ±6V(12V)
80mA Output Current
Low Supply Current: 4.6mA/Amplifier
LT1395: SO-8, SOT23-5 and SOT23-6 Packages
LT1396: SO-8 and MSOP Packages
LT1397: SO-14 and SSOP-16 Packages
U
APPLICATIO S
■
■
■
■
The LT1395/LT1396/LT1397 operate on all supplies from
a single 4V to ±6V. At ±5V, they draw 4.6mA of supply
current per amplifier. The LT1395CS6 also adds a shutdown pin. When disabled, the LT1395CS6 draws virtually
zero supply current and its output becomes high impedance. The LT1395CS6 will turn on in only 30ns and turn off
in 40ns, making it ideal in spread spectrum and portable
equipment applications.
The LT1395/LT1396/LT1397 are manufactured on Linear
Technology’s proprietary complementary bipolar process.
They have standard single/dual/quad pinouts and they are
optimized for use on supply voltages of ±5V.
Cable Drivers
Video Amplifiers
MUX Amplifiers
High Speed Portable Equipment
IF Amplifiers
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
■
The LT ®1395/LT1396/LT1397 are single/dual/quad
400MHz current feedback amplifiers with an 800V/µs slew
rate and the ability to drive up to 80mA of output current.
TYPICAL APPLICATIO
Unity-Gain Video Loop-Through Amplifier
R G1
1.02k
R G2
63.4Ω
R F1
255Ω
Loop-Through Amplifier
Frequency Response
R F2
255Ω
10
0
NORMAL SIGNAL
3.01k
0.67pF
VIN –
–
1/2
LT1396
3.01k VIN+
+
12.1k
0.67pF
BNC INPUTS
HIGH INPUT RESISTANCE DOES NOT LOAD CABLE
EVEN WHEN POWER IS OFF
1/2
LT1396
VOUT
+
12.1k
1% RESISTORS
FOR A GAIN OF G:
VOUT = G (VIN+ – VIN – )
R F1 = RF2
R G1 = (5G – 1) RF2
R F2
RG2 =
(5G – 1)
TRIM CMRR WITH RG1
GAIN (dB)
–
–10
–20
–30
–40
COMMON MODE SIGNAL
–50
–60
100
1k
10k 100k
1M
10M 100M 1G
FREQUENCY (Hz)
1395/6/7 TA02
1395/6/7 TA01
1
LT1395/LT1396/LT1397
W W
W
AXI U
U
ABSOLUTE
RATI GS
(Note 1)
Total Supply Voltage (V + to V –) ........................... 12.6V
Input Current (Note 2) ....................................... ±10mA
Output Current ................................................. ±100mA
Differential Input Voltage (Note 2) ........................... ±5V
Output Short-Circuit Duration (Note 3) ........ Continuous
Operating Temperature Range (Note 4) . – 40°C to 85°C
Specified Temperature Range (Note 5) .. – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Junction Temperature (Note 6) ............................ 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
W
U
U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
TOP VIEW
NC 1
–IN 2
+IN 3
8
–
+
V– 4
7
V+
6
OUT
5
TOP VIEW
NC
5 V+
OUT 1
V– 2
+
V– 2
–
+IN 3
4 –IN
+
–
+IN 3
NC
TOP VIEW
6 V+
OUT 1
OUT A
–IN A
+IN A
V–
5 EN
4 –IN
1
2
3
4
–
+
–
+
8
7
6
5
MS8 PACKAGE
8-LEAD PLASTIC MSOP
S5 PACKAGE
5-LEAD PLASTIC SOT-23
S6 PACKAGE
6-LEAD PLASTIC SOT-23
TJMAX = 150°C, θJA = 150°C/W
TJMAX = 150°C, θJA = 250°C/W
TJMAX = 150°C, θJA = 230°C/W
ORDER
PART NUMBER
ORDER
PART NUMBER
ORDER
PART NUMBER
ORDER
PART NUMBER
LT1395CS8
LT1395CS5
LT1395CS6
LT1396CMS8
S8 PART MARKING
S5 PART MARKING
S6 PART MARKING
MS8 PART MARKING
1395
LTMA
LTMF
LTDY
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 250°C/W
TOP VIEW
TOP VIEW
TOP VIEW
–IN A 2
+IN A 3
8
–
+
–
+
V– 4
OUT A
1
14 OUT D
–IN A
2
– 13 –IN D
+
12 +IN D
+IN A
3
V+
4
+IN B
5
–IN B
6
OUT B
7
10 OUT C
NC
8
9
OUT A 1
OUT A 1
V+
7
OUT B
6
–IN A
5
+IN B
S8 PACKAGE
8-LEAD PLASTIC SO
–IN A 2
+IN A 3
V+
–
+
11
4
+IN B 5
–IN B 6
+
–
V–
+ 10 +IN C
–
9 –IN C
8
OUT B 7
OUT C
S PACKAGE
14-LEAD PLASTIC SO
16 OUT D
– 15 –IN D
+
14 +IN D
–
+
13 V –
+ 12 +IN C
–
11 –IN C
+
–
NC
GN PACKAGE
16-LEAD PLASTIC SSOP
TJMAX = 150°C, θJA = 150°C/W
TJMAX = 150°C, θJA = 100°C/W
ORDER
PART NUMBER
ORDER
PART NUMBER
ORDER
PART NUMBER
LT1396CS8
LT1397CS
LT1397CGN
TJMAX = 150°C, θJA = 135°C/W
S8 PART MARKING
GN PART MARKING
1396
1397
Consult factory for Industrial and Military grade parts.
2
V+
OUT B
–IN A
+IN B
LT1395/LT1396/LT1397
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the specified operating temperature range, otherwise specifications are at TA = 25°C.
For each amplifier: VCM = 0V, VS = ±5V, EN = 0.5V, pulse tested, unless otherwise noted. (Note 5)
SYMBOL
PARAMETER
VOS
Input Offset Voltage
CONDITIONS
MIN
TYP
MAX
UNITS
1
±10
±12
mV
mV
●
∆VOS/∆T
Input Offset Voltage Drift
IIN+
Noninverting Input Current
10
±25
±30
µA
µA
10
±50
±60
µA
µA
●
IIN–
µV/°C
15
●
Inverting Input Current
●
en
Input Noise Voltage Density
f = 1kHz, RF = 1k, RG = 10Ω, RS = 0Ω
4.5
nV/√Hz
+ in
Noninverting Input Noise Current Density
f = 1kHz
6
pA/√Hz
– in
Inverting Input Noise Current Density
f = 1kHz
25
pA/√Hz
RIN
Input Resistance
VIN = ±3.5V
CIN
Input Capacitance
VINH
Input Voltage Range, High
VS = ±5V
VS = 5V, 0V
●
VINL
Input Voltage Range, Low
VS = ±5V
VS = 5V, 0V
●
VOUTH
Output Voltage Swing, High
VS = ±5V
VS = ±5V
VS = 5V, 0V
●
VS = ±5V
VS = ±5V
VS = 5V, 0V
●
VS = ±5V, RL = 150Ω
VS = ±5V, RL = 150Ω
VS = 5V, 0V; RL = 150Ω
●
VS = ±5V, RL = 150Ω
VS = ±5V, RL = 150Ω
VS = 5V, 0V; RL = 150Ω
●
●
VOUTL
VOUTH
VOUTL
Output Voltage Swing, Low
Output Voltage Swing, High
Output Voltage Swing, Low
●
0.3
3.5
1
MΩ
2.0
pF
4.0
4.0
V
V
– 4.0
1.0
3.9
3.7
– 3.5
4.2
V
V
V
4.2
– 4.2
– 3.9
– 3.7
0.8
3.4
3.2
3.6
– 3.4
– 3.2
0.6
CMRR
Common Mode Rejection Ratio
VCM = ±3.5V
– ICMRR
Inverting Input Current
Common Mode Rejection
VCM = ±3.5V
VCM = ±3.5V
●
●
42
V
V
V
V
V
V
3.6
– 3.6
V
V
52
V
V
V
dB
16
22
µA/V
µA/V
1
2
3
µA/V
µA/V
2
7
µA/V
10
PSRR
Power Supply Rejection Ratio
VS = ±2V to ±5V
+ IPSRR
Noninverting Input Current
Power Supply Rejection
VS = ±2V to ±5V
– IPSRR
Inverting Input Current
Power Supply Rejection
VS = ±2V to ±5V
AV
Large-Signal Voltage Gain
VOUT = ±2V, RL = 150Ω
50
65
dB
ROL
Transimpedance, ∆VOUT/∆IIN–
VOUT = ±2V, RL = 150Ω
40
100
kΩ
IOUT
Maximum Output Current
RL = 0Ω
●
IS
Supply Current per Amplifier
VOUT = 0V
●
4.6
6.5
mA
Disable Supply Current
EN Pin Voltage = 4.5V, RL = 150Ω
(LT1395CS6 only)
●
0.1
100
µA
Enable Pin Current
(LT1395CS6 only)
30
110
200
µA
µA
IEN
56
70
●
●
80
mA
●
SR
Slew Rate (Note 7)
AV = – 1, RL = 150Ω
dB
500
800
V/µs
3
LT1395/LT1396/LT1397
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the specified operating temperature range, otherwise specifications are at TA = 25°C.
For each amplifier: VCM = 0V, VS = ±5V, pulse tested, unless otherwise noted. (Note 5)
SYMBOL
PARAMETER
CONDITIONS
TYP
MAX
tON
Turn-On Delay Time (Note 9)
RF = RG = 255Ω, RL = 100Ω, (LT1395CS6 only)
30
75
ns
tOFF
Turn-Off Delay Time (Note 9)
RF = RG = 255Ω, RL = 100Ω, (LT1395CS6 only)
40
100
ns
– 3dB BW
–3dB Bandwidth
AV = 1, RF = 374Ω, RL = 100Ω
AV = 2, RF = RG = 255Ω, RL = 100Ω
400
350
MHz
MHz
0.1dB BW 0.1dB Bandwidth
AV = 1, RF = 374Ω, RL = 100Ω
AV = 2, RF = RG = 255Ω, RL = 100Ω
100
100
MHz
MHz
tr, tf
Small-Signal Rise and Fall Time
RF = RG = 255Ω, RL = 100Ω, VOUT = 1VP-P
1.3
ns
tPD
Propagation Delay
RF = RG = 255Ω, RL = 100Ω, VOUT = 1VP-P
2.5
ns
os
Small-Signal Overshoot
RF = RG = 255Ω, RL = 100Ω, VOUT = 1VP-P
10
%
tS
Settling Time
0.1%, AV = – 1, RF = RG = 280Ω, RL = 150Ω
25
ns
dG
Differential Gain (Note 8)
RF = RG = 255Ω, RL = 150Ω
0.02
%
dP
Differential Phase (Note 8)
RF = RG = 255Ω, RL = 150Ω
0.04
DEG
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: This parameter is guaranteed to meet specified performance
through design and characterization. It has not been tested.
Note 3: A heat sink may be required depending on the power supply
voltage and how many amplifiers have their outputs short circuited.
Note 4: The LT1395C/LT1396C/LT1397C are guaranteed functional over
the operating temperature range of – 40°C to 85°C.
Note 5: The LT1395C/LT1396C/LT1397C are guaranteed to meet specified
performance from 0°C to 70°C. The LT1395C/LT1396C/LT1397C are
designed, characterized and expected to meet specified performance from
– 40°C and 85°C but is not tested or QA sampled at these temperatures.
For guaranteed I-grade parts, consult the factory.
Note 6: TJ is calculated from the ambient temperature TA and the
power dissipation PD according to the following formula:
LT1395CS5: TJ = TA + (PD • 250°C/W)
LT1396CS6: TJ = TA + (PD • 230°C/W)
MIN
UNITS
LT1395CS8: TJ = TA + (PD • 150°C/W)
LT1396CS8: TJ = TA + (PD • 150°C/W)
LT1396CMS8: TJ = TA + (PD • 250°C/W)
LT1397CS14: TJ = TA + (PD • 100°C/W)
LT1397CGN16: TJ = TA + (PD • 135°C/W)
Note 7: Slew rate is measured at ±2V on a ±3V output signal.
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°.
Ten identical amplifier stages were cascaded giving an effective
resolution of 0.01% and 0.01°.
Note 9: For LT1395CS6, turn-on delay time (tON) is measured from
control input to appearance of 1V(50%) at the output, for VIN = 1V and
AV = 2. Likewise, turn-off delay time (tOFF) is measured from control
input to appearance of 1V(50%) on the output for VIN = 1V and
AV = 2. This specification is guaranteed by design and characterization.
W U
TYPICAL AC PERFOR A CE
SMALL SIGNAL
0.1dB BW (MHz)
SMALL SIGNAL
PEAKING (dB)
AV
RL (Ω)
RF (Ω)
±5
1
100
374
–
400
100
0.1
±5
2
100
255
255
350
100
0.1
±5
–1
100
280
280
350
100
0.1
4
RG (Ω)
SMALL SIGNAL
– 3dB BW (MHz)
VS (V)
LT1395/LT1396/LT1397
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Closed-Loop Gain vs Frequency
(AV = 2)
0
–2
4
–2
–4
GAIN (dB)
6
–6
2
1G
1M
10M
100M
VS = ±5V
FREQUENCY (Hz)
VIN = –10dBm
RF = RG = 255Ω
RL = 100Ω
1395/6/7 G01
1G
1M
10M
100M
VS = ±5V
FREQUENCY (Hz)
VIN = –10dBm
RF = RG = 280Ω
RL = 100Ω
1395/6/7 G02
Large-Signal Transient Response
(AV = 2)
OUTPUT (1V/DIV)
OUTPUT (1V/DIV)
TIME (10ns/DIV)
1395/6/7 G04
VS = ±5V
TIME (10ns/DIV)
VIN = ±1.25V
RF = RG = 255Ω
RL = 100Ω
2nd and 3rd Harmonic Distortion
vs Frequency
1395/6/7 G05
VS = ±5V
TIME (10ns/DIV)
VIN = ±2.5V
RF = RG = 280Ω
RL = 100Ω
Maximum Undistorted Output
Voltage vs Frequency
TA = 25°C
RF = RG = 255Ω
RL = 100Ω
50 VS = ± 5V
VOUT = 2VPP
40
70
HD3
HD2
80
90
AV = +1
AV = +2
5
4
3
100
TA = 25°C
RF = 374Ω (AV = 1)
RF = RG = 255Ω (AV = 2)
RL = 100Ω
VS = ± 5V
1k
10k
100k
1M
FREQUENCY (Hz)
10M
100M
1395/6/7 G07
1M
10M
FREQUENCY (Hz)
1395/6/7 G08
+ PSRR
40
30
10
100M
– PSRR
50
20
2
110
60
6
PSRR (dB)
OUTPUT VOLTAGE (VP-P)
70
80
7
60
1395/6/7 G06
PSRR vs Frequency
8
30
1G
1395/6/7 G03
Large-Signal Transient Response
(AV = – 1)
OUTPUT (1V/DIV)
Large-Signal Transient Response
(AV = 1)
VS = ±5V
VIN = ±2.5V
RF = 374Ω
RL = 100Ω
–4
–6
0
1M
10M
100M
VS = ±5V
FREQUENCY (Hz)
VIN = –10dBm
RF = 374Ω
RL = 100Ω
DISTORTION (dB)
Closed-Loop Gain vs Frequency
(AV = – 1)
0
GAIN (dB)
GAIN (dB)
Closed-Loop Gain vs Frequency
(AV = 1)
TA = 25°C
RF = RG = 255Ω
RL = 100Ω
AV = +2
0
10k
100k
1M
10M
FREQUENCY (Hz)
100M
1395/6/7 G09
5
LT1395/LT1396/LT1397
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Input Voltage Noise and Current
Noise vs Frequency
100
100
–in
+in
10
en
1
10
30
10
1
0.1
0.01
10k
100 300 1k 3k 10k 30k 100k
FREQUENCY (Hz)
100k
RF = RG = 255Ω
RL = 50Ω
AV = +2
VS = ± 5V
OUTPUT IMPEDANCE (DISABLED) (Ω)
OUTPUT IMPEDANCE (Ω)
100k
1M
10M
FREQUENCY (Hz)
RF = R G
AV = +2
VS = ± 5V
PEAKING ≤ 5dB
900
1500
2100
2700
FEEDBACK RESISTANCE (Ω)
Supply Current vs Supply Voltage
RF = RG = 255Ω
VS = ± 5V
OVERSHOOT < 2%
30
20
10
0
– 10
100
CAPACITIVE LOAD (pF)
ENABLE PIN CURRENT (µA)
OUTPUT VOLTAGE SWING (V)
1
VS = ± 5V
–1
–2
RL = 100k
2
1000
0
RL = 150Ω
VS = ± 5V
EN = 0V
– 30
– 40
EN = –5V
– 50
– 60
– 70
–4
–5
50
25
0
75 100
–50 –25
AMBIENT TEMPERATURE (°C)
125
1395/6/7 G16
1
2
7
3
5
6
4
SUPPLY VOLTAGE (± V)
– 80
– 50 – 25
50
100
25
75
0
AMBIENT TEMPERATURE (°C)
8
9
1395/6/7 G15
Positive Supply Current per
Amplifier vs Temperature
– 20
2
EN = 0V,
ALL NON-DISABLE DEVICES
3
LT1395CS6 Enable Pin Current
vs Temperature
4
–3
4
1395/6/7 G14
Output Voltage Swing
vs Temperature
RL = 150Ω
EN = V –
0
10
1395/6/7 G13
0
5
1
3300
5
100M
6
SUPPLY CURRENT (mA)
10
OUTPUT SERIES RESISTANCE (Ω)
CAPACITIVE LOAD (pF)
100
1M
10M
FREQUENCY (Hz)
1395/6/7 G12
40
1000
RL = 100k
1k
Capacitive Load
vs Output Series Resistor
Maximum Capacitive Load
vs Feedback Resistor
3
10k
1395/6/7 G11
1395/6/7 G10
1
300
RF = 374Ω
AV = +1
VS = ± 5V
100
100k
100M
125
1395/6/7 G17
POSITIVE SUPPLY CURRENT PER AMPLIFIER (mA)
INPUT NOISE (nV/√Hz OR pA/√Hz)
1000
6
LT1395CS6 Output Impedance
(Disabled) vs Frequency
Output Impedance vs Frequency
5.00
VS = ± 5V
EN = – 5V
4.75
4.50
EN = 0V,
ALL NON-DISABLE DEVICES
4.25
4.00
3.75
3.50
3.25
3.00
–50 –25
75 100
0
50
25
AMBIENT TEMPERATURE (°C)
125
1395/6/7 G18
LT1395/LT1396/LT1397
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Input Offset Voltage
vs Temperature
3.0
Input Bias Currents
vs Temperature
15
VS = ± 5V
VS = ± 5V
INPUT BIAS CURRENT (µA)
INPUT OFFSET VOLTAGE (mV)
2.5
2.0
1.5
1.0
0.5
0
12
IB+
IB –
9
6
3
– 0.5
–1.0
– 50 – 25
75 100
50
25
AMBIENT TEMPERATURE (°C)
0
125
0
–50 –25
50
100
25
75
0
AMBIENT TEMPERATURE (°C)
1395/6/7 G19
1395/6/7 G20
Propagation Delay
Rise Time and Overshoot
OUTPUT (200mV/DIV)
TIME (10ns/DIV)
OUTPUT (200mV/DIV)
RL = 100Ω
RF = RG = 255Ω
f = 10MHz
1395/6/7 G21
tPD = 2.5ns
VOUT (200mV/DIV)
OS = 10%
INPUT (100mV/DIV)
Square Wave Response
125
tr = 1.3ns
1395/6/7 G22
1395/6/7 G23
TIME (500ps/DIV)
AV = +2
RL = 100Ω
RF = RG = 255Ω
AV = +2
TIME (500ps/DIV)
RL = 100Ω
RF = RG = 255Ω
U
U
U
PIN FUNCTIONS
LT1395CS5
LT1395CS6
OUT (Pin 1): Output.
OUT (Pin 1): Output.
V – (Pin 2): Negative Supply Voltage, Usually –5V.
V – (Pin 2): Negative Supply Voltage, Usually –5V.
+IN (Pin 3): Noninverting Input.
+IN (Pin 3): Noninverting Input.
–IN (Pin 4): Inverting Input.
–IN (Pin 4): Inverting Input.
V + (Pin 5): Positive Supply Voltage, Usually 5V.
EN (Pin 5): Enable Pin. Logic low to enable.
V + (Pin 6): Positive Supply Voltage, Usually 5V.
7
LT1395/LT1396/LT1397
U
U
U
PIN FUNCTIONS
LT1395CS8
OUT B (Pin 7): B Channel Output.
NC (Pin 1): No Connection.
OUT C (Pin 8): C Channel Output.
– IN (Pin 2): Inverting Input.
– IN C (Pin 9): Inverting Input of C Channel Amplifier.
+ IN (Pin 3): Noninverting Input.
+ IN C (Pin 10): Noninverting Input of C Channel Amplifier.
V – (Pin 4): Negative Supply Voltage, Usually – 5V.
V – (Pin 11): Negative Supply Voltage, Usually – 5V.
NC (Pin 5): No Connection.
+ IN D (Pin 12): Noninverting Input of D Channel Amplifier.
OUT (Pin 6): Output.
– IN D (Pin 13): Inverting Input of D Channel Amplifier.
V + (Pin 7): Positive Supply Voltage, Usually 5V.
OUT D (Pin 14): D Channel Output.
NC (Pin 8): No Connection.
LT1397CGN
LT1396CMS8, LT1396CS8
OUT A (Pin 1): A Channel Output.
OUT A (Pin 1): A Channel Output.
– IN A (Pin 2): Inverting Input of A Channel Amplifier.
– IN A (Pin 2): Inverting Input of A Channel Amplifier.
+ IN A (Pin 3): Noninverting Input of A Channel Amplifier.
+ IN A (Pin 3): Noninverting Input of A Channel Amplifier.
V + (Pin 4): Positive Supply Voltage, Usually 5V.
V – (Pin 4): Negative Supply Voltage, Usually – 5V.
+ IN B (Pin 5): Noninverting Input of B Channel Amplifier.
+ IN B (Pin 5): Noninverting Input of B Channel Amplifier.
– IN B (Pin 6): Inverting Input of B Channel Amplifier.
– IN B (Pin 6): Inverting Input of B Channel Amplifier.
OUT B (Pin 7): B Channel Output.
OUT B (Pin 7): B Channel Output.
NC (Pin 8): No Connection.
V + (Pin 8):
NC (Pin 9): No Connection.
Positive Supply Voltage, Usually 5V.
LT1397CS
OUT C (Pin 10): C Channel Output.
OUT A (Pin 1): A Channel Output.
– IN C (Pin 11): Inverting Input of C Channel Amplifier.
– IN A (Pin 2): Inverting Input of A Channel Amplifier.
+ IN C (Pin 12): Noninverting Input of C Channel Amplifier.
+ IN A (Pin 3): Noninverting Input of A Channel Amplifier.
V – (Pin 13): Negative Supply Voltage, Usually – 5V.
V + (Pin 4): Positive Supply Voltage, Usually 5V.
+ IN D (Pin 14): Noninverting Input of D Channel Amplifier.
+ IN B (Pin 5): Noninverting Input of B Channel Amplifier.
– IN D (Pin 15): Inverting Input of D Channel Amplifier.
– IN B (Pin 6): Inverting Input of B Channel Amplifier.
OUT D (Pin 16): D Channel Output.
U
W
U
UO
APPLICATI
S I FOR ATIO
Feedback Resistor Selection
The small-signal bandwidth of the LT1395/LT1396/LT1397
is 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
8
resistor, the closed-loop gain and the load resistor. The
LT1395/LT1396/LT1397 have been optimized for ±5V
supply operation and have a – 3dB bandwidth of 400MHz
at a gain of 1 and 350MHz at a gain of 2. Please refer to the
resistor selection guide in the Typical AC Performance
table.
LT1395/LT1396/LT1397
U
W
U
UO
APPLICATI
S I FOR ATIO
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).
Capacitive Loads
The LT1395/LT1396/LT1397 can drive many capacitive
loads directly when the proper value of feedback resistor
is used. The required value for the feedback resistor will
increase as load capacitance increases and as closed-loop
gain decreases. Alternatively, a small resistor (5Ω to 35Ω)
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. See the Typical Performance Characteristics curves.
Power Supplies
The LT1395/LT1396/LT1397 will operate from single or
split supplies from ±2V (4V total) to ±6V (12V 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 2.5mV per
volt of supply mismatch. The inverting bias current will
typically change about 10µA per volt of supply mismatch.
the feedback resistor and internal capacitance. At a gain
of 2 with 255Ω feedback and gain resistors and ±5V
supplies, the output slew rate is typically 800V/µs. Larger
feedback resistors will reduce the slew rate as will lower
supply voltages.
Enable/ Disable
The LT1395CS6 has a unique high impedance, zero
supply current mode which is controlled by the EN pin.
The LT1395CS6 is designed to operate with CMOS logic;
it draws virtually zero current when the EN pin is high. To
activate the amplifier, its EN pin is normally pulled to a
logic low. However, supply current will vary as the voltage
between the V + supply and EN is varied. As seen in Figure
1, +IS does vary with (V + – VEN), particularly when the
voltage difference is less than 3V. For normal operation,
it is important to keep the EN pin at least 3V below the V +
supply. If a V + of less than 3V is desired, and the amplifier
will remain enabled at all times, then the EN pin should be
tied to the V – supply. The enable pin current is approximately 30µA when activated. If using CMOS open-drain
logic, an external 1k pull-up resistor is recommended to
ensure that the LT1395CS6 remains disabled in spite of
any CMOS drain leakage currents.
The enable/disable times are very fast when driven from
standard 5V CMOS logic. The LT1395CS6 enables in
about 30ns (50% point to 50% point) while operating on
±5V supplies (Figure 2). Likewise, the disable time is
approximately 40ns (50% point to 50% point) (Figure 3).
Slew Rate
The input slew rate of the LT1395/LT1396/LT1397 is
approximately 600V/µs and is set by internal currents and
capacitances. The output slew rate is set by the value of
TA = 25°C
V + = 5V
4.5
4.0
V – = 0V
3.5
+IS (mA)
Unlike a traditional voltage feedback op amp, the slew rate
of a current feedback amplifier is not independent of the
amplifier gain configuration. In a current feedback amplifier, both the input stage and the output stage have slew rate
limitations. In the inverting mode, and for gains of 2 or more
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 2 in the noninverting mode,
the overall slew rate is limited by the input stage.
5.0
3.0
V – = – 5V
2.5
2.0
1.5
1.0
0.5
0
0
1
2
4
3
V + – VEN (V)
5
6
7
1395/6/7 F01
Figure 1. + IS
vs (V +
– VEN)
9
LT1395/LT1396/LT1397
W
U
U
UO
APPLICATI
S I FOR ATIO
OUTPUT
EN
VS = ±5V
VIN = 1V
RF = 255Ω
RG = 255Ω
RL = 100Ω
1395/6/7 F02
Figure 2. Amplifier Enable Time, AV = 2
OUTPUT
EN
VS = ±5V
VIN = 1V
RF = 255Ω
RG = 255Ω
RL = 100Ω
1395/6/7 F03
Figure 3. Amplifier Disable Time, AV = 2
Differential Input Signal Swing
To avoid any breakdown condition on the input transistors, the differential input swing must be limited to ±5V. In
normal operation, the differential voltage between the
input pins is small, so the ±5V limit is not an issue.
in the Y output. Amplifier A1 is configured in a noninverting gain of 2 with the bottom of the gain resistor R2 tied
to the Y output. The output of amplifier A1 thus results in
the color-difference output R-Y.
The B input is similar to the R input. It arrives via 75Ω
coax, and is routed to the noninverting input of LT1397
amplifier A4, and to a 2320Ω resistor R10. There is also
a 76.8Ω termination resistor R13, which yields a 75Ω
input impedance when considered in parallel with R10.
R10 also connects to the inverting input of amplifier A2,
adding the B contribution to the Y signal as discussed
above. Amplifier A4 is configured in a noninverting gain
of 2 configuration with the bottom of the gain resistor R4
tied to the Y output. The output of amplifier A4 thus
results in the color-difference output B-Y.
The G input also arrives via 75Ω coax and adds its
contribution to the Y signal via a 432Ω resistor R9, which
is tied to the inverting input of amplifier A2. There is also
a 90.9Ω termination resistor R12, which yields a 75Ω
termination when considered in parallel with R9. Using
superposition, it is straightforward to determine the
output of amplifier A2. Although inverted, it sums the R,
G and B signals in the standard proportions of 0.3R,
0.59G and 0.11B that are used to create the Y signal.
Amplifier A3 then inverts and amplifies the signal by 2,
resulting in the Y output.
+
75Ω
SOURCES
R8
845Ω
A1
1/4 LT1397
R
R11
82.5Ω
Buffered RGB to Color-Difference Matrix
An LT1397 can be used to create buffered color-difference signals from RGB inputs (Figure 4). In this application, the R input arrives via 75Ω coax. It is routed to the
noninverting input of LT1397 amplifier A1 and to a 845Ω
resistor R8. There is also an 82.5Ω termination resistor
R11, which yields a 75Ω input impedance at the R input
when considered in parallel with R8. R8 connects to the
inverting input of a second LT1397 amplifier (A2), which
also sums the weighted G and B inputs to create a
–0.5 • Y output. LT1397 amplifier A3 then takes the
–0.5 • Y output and amplifies it by a gain of –2, resulting
10
R1
255Ω
R9
432Ω
R7
255Ω
G
R12
90.9Ω
R-Y
–
R10
2320Ω
B
R13
76.8Ω
–
A2
1/4 LT1397
+
R6
127Ω
R5
255Ω
R2
255Ω
–
A3
1/4 LT1397
Y
+
R4
255Ω
R3
255Ω
–
ALL RESISTORS 1%
VS = ±5V
A4
1/4 LT1397
+
B-Y
1395/6/7 F04
Figure 4. Buffered RGB to Color-Difference Matrix
LT1395/LT1396/LT1397
U
W
U
UO
APPLICATI
S I FOR ATIO
Buffered Color-Difference to RGB Matrix
An LT1395 combined with an LT1396 can be used to
create buffered RGB outputs from color-difference signals (Figure 5). The R output is a back-terminated 75Ω
signal created using resistor R5 and amplifier A1 configured for a gain of +2 via 255Ω resistors R3 and R4. The
noninverting input of amplifier A1 is connected via 1k
resistors R1 and R2 to the Y and R-Y inputs respectively,
resulting in cancellation of the Y signal at the amplifier
input. The remaining R signal is then amplified by A1.
The B output is also a back-terminated 75Ω signal
created using resistor R16 and amplifier A3 configured
for a gain of +2 via 255Ω resistors R14 and R15. The
noninverting input of amplifier A3 is connected via 1k
resistors R12 and R13 to the Y and B-Y inputs respectively, resulting in cancellation of the Y signal at the
amplifier input. The remaining B signal is then amplified
by A3.
The G output is the most complicated of the three. It is a
weighted sum of the Y, R-Y and B-Y inputs. The Y input
is attenuated via resistors R6 and R7 such that amplifier
A2’s noninverting input sees 0.83Y. Using superposition,
we can calculate the positive gain of A2 by assuming that
R8 and R9 are grounded. This results in a gain of 2.41 and
a contribution at the output of A2 of 2Y. The R-Y input is
amplified by A2 with the gain set by resistors R8 and R10,
giving an amplification of –1.02. This results in a contribution at the output of A2 of 1.02Y – 1.02R. The B-Y input
is amplified by A2 with the gain set by resistors R9 and
R10, giving an amplification of – 0.37. This results in a
contribution at the output of A2 of 0.37Y – 0.37B.
If we now sum the three contributions at the output of A2,
we get:
A2OUT = 3.40Y – 1.02R – 0.37B
It is important to remember though that Y is a weighted
sum of R, G and B such that:
Y = 0.3R + 0.59G + 0.11B
If we substitute for Y at the output of A2 we then get:
A2OUT = (1.02R – 1.02R) + 2G + (0.37B – 0.37B)
= 2G
The back-termination resistor R11 then halves the output
of A2 resulting in the G output.
R1
1k
Y
R2
1k
+
A1
1/2 LT1396
R-Y
–
R
R3
267Ω
R4
267Ω
R6
205Ω
+
A2
LT1395
R7
1k
R8
261Ω
R5
75Ω
–
R11
75Ω
G
R10
267Ω
R9
698Ω
B-Y
R12
1k
R13
1k
ALL RESISTORS 1%
VS = ± 5V
+
A3
1/2 LT1396
–
R16
75Ω
B
R14
267Ω
R15
267Ω
1395/6/7 F05
Figure 5. Buffered Color-Difference to RGB Matrix
11
LT1395/LT1396/LT1397
W
W
SI PLIFIED SCHE ATIC , each amplifier
V+
–IN
+IN
OUT
EN
(LT1395CS6 ONLY)
FOR ALL
NON-DISABLE
DEVICES
V–
1395/6/7 SS
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
GN Package
16-Lead Plastic SSOP (Narrow 0.150)
(LTC DWG # 05-08-1641)
0.189 – 0.196*
(4.801 – 4.978)
16 15 14 13 12 11 10 9
0.229 – 0.244
(5.817 – 6.198)
0.150 – 0.157**
(3.810 – 3.988)
1
0.015 ± 0.004
× 45°
(0.38 ± 0.10)
0.007 – 0.0098
(0.178 – 0.249)
0.053 – 0.068
(1.351 – 1.727)
2 3
4
5 6
7
8
0.004 – 0.0098
(0.102 – 0.249)
0° – 8° TYP
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
12
0.009
(0.229)
REF
0.008 – 0.012
(0.203 – 0.305)
0.0250
(0.635)
BSC
GN16 (SSOP) 1098
LT1395/LT1396/LT1397
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
MS8 Package
8-Lead Plastic MSOP
(LTC DWG # 05-08-1660)
0.118 ± 0.004*
(3.00 ± 0.102)
8
7 6
5
0.118 ± 0.004**
(3.00 ± 0.102)
0.193 ± 0.006
(4.90 ± 0.15)
MSOP (MS8) 1098
1
2 3
4
0.040 ± 0.006
(1.02 ± 0.15)
0.007
(0.18)
0.034 ± 0.004
(0.86 ± 0.102)
0° – 6° TYP
SEATING
PLANE 0.012
(0.30)
0.0256
REF
(0.65)
BSC
0.021 ± 0.006
(0.53 ± 0.015)
0.006 ± 0.004
(0.15 ± 0.102)
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,
PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
S5 Package
5-Lead Plastic SOT-23
(LTC DWG # 05-08-1633)
2.80 – 3.00
(0.110 – 0.118)
(NOTE 3)
2.60 – 3.00
(0.102 – 0.118)
1.50 – 1.75
(0.059 – 0.069)
0.35 – 0.55
(0.014 – 0.022)
1.90
(0.074)
REF
0.00 – 0.15
(0.00 – 0.006)
0.09 – 0.20
(0.004 – 0.008)
(NOTE 2)
0.95
(0.037)
REF
0.90 – 1.45
(0.035 – 0.057)
0.35 – 0.50
0.90 – 1.30
(0.014 – 0.020)
(0.035 – 0.051)
FIVE PLACES (NOTE 2)
S5 SOT-23 0599
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DIMENSIONS ARE INCLUSIVE OF PLATING
3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
4. MOLD FLASH SHALL NOT EXCEED 0.254mm
5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)
13
LT1395/LT1396/LT1397
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S6 Package
6-Lead Plastic SOT-23
(LTC DWG # 05-08-1634)
2.80 – 3.00
(0.110 – 0.118)
(NOTE 3)
2.6 – 3.0
(0.110 – 0.118)
1.50 – 1.75
(0.059 – 0.069)
0.35 – 0.55
(0.014 – 0.022)
0.95
(0.037)
REF
1.90
(0.074)
REF
0.00 – 0.15
(0.00 – 0.006)
0.09 – 0.20
(0.004 – 0.008)
(NOTE 2)
0.90 – 1.45
(0.035 – 0.057)
0.35 – 0.50
0.90 – 1.30
(0.014 – 0.020)
(0.035 – 0.051)
SIX PLACES (NOTE 2)
S6 SOT-23 0898
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DIMENSIONS ARE INCLUSIVE OF PLATING
3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
4. MOLD FLASH SHALL NOT EXCEED 0.254mm
5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
8
7
6
5
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
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°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
*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
14
2
3
4
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
SO8 1298
LT1395/LT1396/LT1397
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S Package
14-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.337 – 0.344*
(8.560 – 8.738)
14
13
12
11
10
9
8
0.228 – 0.244
(5.791 – 6.197)
0.150 – 0.157**
(3.810 – 3.988)
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
2
3
4
5
6
0.053 – 0.069
(1.346 – 1.752)
0.008 – 0.010
(0.203 – 0.254)
0.004 – 0.010
(0.101 – 0.254)
0° – 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.014 – 0.019
(0.355 – 0.483)
TYP
7
0.050
(1.270)
BSC
*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
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.
S14 1298
15
LT1395/LT1396/LT1397
UO
TYPICAL APPLICATI
Single Supply RGB Video Amplifier
The LT1395 can be used with a single supply voltage of
6V or more to drive ground-referenced RGB video. In
Figure 6, two 1N4148 diodes D1 and D2 have been placed
in series with the output of the LT1395 amplifier A1 but
within the feedback loop formed by resistor R8. These
diodes effectively level-shift A1’s output downward by 2
diodes, allowing the circuit output to swing to ground.
input. Assuming a 75Ω source impedance for the signal
driving VIN, the Thevenin equivalent signal arriving at
A1’s positive input is 3V + 0.4VIN, with a source impedance of 714Ω. The combination of these two inputs gives
an output at the cathode of D2 of 2 • VIN with no additional
DC offset. The 75Ω back termination resistor R9 halves
the signal again such that VOUT equals a buffered version
of VIN.
Amplifier A1 is used in a positive gain configuration. The
feedback resistor R8 is 255Ω. The gain resistor is created from the parallel combination of R6 and R7, giving
a Thevenin equivalent 63.5Ω connected to 3.75V. This
gives an AC gain of + 5 from the noninverting input of
amplifier A1 to the cathode of D2. However, the video
input is also attenuated before arriving at A1’s positive
It is important to note that the 4.7µF capacitor C1 has
been added to provide enough current to maintain the
voltage drop across diodes D1 and D2 when the circuit
output drops low enough that the diodes might otherwise
turn off. This means that this circuit works fine for
continuous video input, but will require that C1 charge up
after a period of inactivity at the input.
5V
R1
1000Ω
R6
84.5Ω
+
A1
LT1395
R2
1300Ω
–
R3
160Ω
VIN
R4
75Ω
R5
2.32Ω
C1
4.7µF
VS
6V TO 12V
D2
D1
1N4148 1N4148
R9
75Ω
VOUT
R8
255Ω
1395/6/7 TA03
R7
255Ω
Figure 6. Single Supply RGB Video Amplifier (1 of 4 Channels)
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1227/LT1229/LT1230
140MHz Single/Dual/Quad Current Feedback Amplifier
1100V/µs Slew Rate, Single Adds Shutdown Pin
LT1252/LT1253/LT1254
Low Cost Video Amplifiers
Single, Dual and Quad 100MHz Current Feedback Amplifiers
LT1398/LT1399
Dual/Triple Current Feedback Amplifiers
300MHz Bandwidth, 0.1dB Flatness > 150MHz with Shutdown
LT1675
Triple 2:1 Buffered Video Mulitplexer
2.5ns Switching Time, 250MHz Bandwidth
LT1363/LT1364/LT1365
70MHz Single/Dual/Quad Op Amps
1000V/µs Slew Rate, Voltage Feedback
16
Linear Technology Corporation
139567fa LT/LCG 0900 2K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1999