LT1399IS#TR [Linear]
LT1399 - Low Cost Dual and Triple 300MHz Current Feedback Amplifiers with Shutdown; Package: SO; Pins: 16; Temperature Range: -40°C to 85°C;
| 型号： | LT1399IS#TR |
| 厂家： | 
Linear |
| 描述： | LT1399 - Low Cost Dual and Triple 300MHz Current Feedback Amplifiers with Shutdown; Package: SO; Pins: 16; Temperature Range: -40°C to 85°C 放大器 |
| 文件： | 总16页 (文件大小：232K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LT1398/LT1399/LT1399HV
Low Cost Dual and Triple
300MHz Current Feedback
Amplifiers with Shutdown
U
FEATURES
DESCRIPTIO
The LT®1399 and LT1399HV contain three independent
300MHz current feedback amplifiers, each with a shut-
down pin. The LT1399HV is a higher voltage version of the
LT1399. The LT1398 is a two amplifier version of the
LT1399.
■
300MHz Bandwidth on ±5V (AV = 1, 2 and –1)
■
0.1dB Gain Flatness: 150MHz (AV = 1, 2 and –1)
■
Completely Off in Shutdown, 0µA Supply Current
High Slew Rate: 800V/µs
Wide Supply Range:
■
■
±2V(4V) to ±6V(12V) (LT1398/LT1399)
±2V (4V) to ±7.5V (15V) (LT1399HV)
The LT1398/LT1399 operate on all supplies from a single
4Vto±6V.TheLT1399HVoperatesonallsuppliesfrom4V
to ±7.5V.
■
80mA Output Current
■
Low Supply Current: 4.6mA/Amplifier
Fast Turn-On Time: 30ns
Fast Turn-Off Time: 40ns
■
Each amplifier draws 4.6mA when active. When disabled
eachamplifierdrawszerosupplycurrentanditsoutputbe-
comeshighimpedance.Theamplifiersturnoninonly30ns
andturnoffin40ns,makingthemidealinspreadspectrum
and portable equipment applications.
■
■
16-Pin Narrow SUO/Narrow SSOP Packages
APPLICATIO S
■
RGB Cable Drivers
LCD Drivers
TheLT1398/LT1399/LT1399HVaremanufacturedonLin-
ear Technology’s proprietary complementary bipolar pro-
cess. The LT1399/LT1399HV are pin-for-pin upgrades to
the LT1260 optimized for use on ±5V/±7.5V supplies.
, LTC and LT are registered trademarks of Linear Technology Corporation.
■
■
Spread Spectrum Amplifiers
■
MUX Amplifiers
■
Composite Video Cable Drivers
■
Portable Equipment
U
TYPICAL APPLICATIO
3-Input Video MUX Cable Driver
CHANNEL
SELECT
A
B C
EN A
Square Wave Response
V
IN A
V
IN B
V
IN C
+
97.6Ω
97.6Ω
97.6Ω
R
G
1/3 LT1399
200Ω
–
75Ω
R
324Ω
F
CABLE
V
OUT
OUTPUT
200mV/DIV
EN B
75Ω
+
R
G
1/3 LT1399
200Ω
–
R
324Ω
F
1398/99 TA02
RL = 100Ω
TIME (10ns/DIV)
RF = RG = 324Ω
f = 10MHz
EN C
+
R
1399 TA01
G
1/3 LT1399
200Ω
–
R
F
324Ω
1
LT1398/LT1399/LT1399HV
W W W
U
(Note 1)
ABSOLUTE AXI U RATI GS
Total Supply Voltage (V+ to V–)
Output Short-Circuit Duration (Note 3)........ Continuous
Operating Temperature Range ............... –40°C to 85°C
Specified Temperature Range (Note 4).. –40°C to 85°C
Storage Temperature Range ................ –65°C to 150°C
Junction Temperature (Note 5)............................ 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
LT1398/LT1399 ................................................ 12.6V
LT1399HV ....................................................... 15.5V
Input Current (Note 2) ....................................... ±10mA
Output Current................................................. ±100mA
Differential Input Voltage (Note 2) ........................... ±5V
W
U
/O
PACKAGE RDER I FOR ATIO
TOP VIEW
ORDER PART
ORDER PART
TOP VIEW
NUMBER
NUMBER
1
2
3
4
5
6
7
8
EN R
16
15
14
13
12
11
10
9
–IN R
+IN R
*GND
–IN G
+IN G
*GND
+IN B
–IN B
1
2
3
4
5
6
7
8
EN A
16
15
14
13
12
11
10
9
–IN A
+IN A
*GND
*GND
*GND
*GND
+IN B
–IN B
R
G
B
A
OUT R
OUT A
LT1398CS
LT1399CGN
LT1399CS
LT1399HVCS
+
V
+
V
EN G
GND*
GND*
OUT G
–
V
–
V
OUT B
EN B
GN PART MARKING
1399
OUT B
EN B
B
GN PACKAGE
S PACKAGE
S PACKAGE
16-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 100°C/W
16-LEAD PLASTIC SSOP 16-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 120°C/W (GN)
TJMAX = 150°C, θJA = 100°C/W (S)
*Ground pins are not internally connected. For best channel isolation, connect to ground. Consult factory for Industrial and Military grade parts.
(LT1398/LT1399)
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 = 0V, pulse tested, unless otherwise noted. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
Input Offset Voltage
1.5
10
12
mV
mV
OS
●
●
∆V /∆T
Input Offset Voltage Drift
Noninverting Input Current
15
10
µV/°C
OS
+
I
25
30
µA
µA
IN
●
●
–
I
Inverting Input Current
10
50
60
µA
µA
IN
e
Input Noise Voltage Density
Noninverting Input Noise Current Density
Inverting Input Noise Current Density
Input Resistance
f = 1kHz, R = 1k, R = 10Ω, R = 0Ω
4.5
6
nV/√Hz
pA/√Hz
pA/√Hz
MΩ
n
F
G
S
+i
–i
f = 1kHz
f = 1kHz
n
25
1
n
IN
IN
R
V
IN
= ±3.5V
●
●
0.3
3.5
C
Input Capacitance
Amplifier Enabled
Amplifier Disabled
2.0
2.5
pF
pF
C
V
Output Capacitance
Amplifier Disabled
8.5
pF
OUT
Input Voltage Range, High
V = ±5V
4.0
4.0
V
V
INH
S
V = 5V, 0V
S
2
LT1398/LT1399/LT1399HV
(LT1398/LT1399)
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 = 0V, pulse tested, unless otherwise noted. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
V = ±5V
MIN
TYP
MAX
UNITS
V
Input Voltage Range, Low
●
●
●
●
–3.5
–4.0
1.0
V
V
INL
S
V = 5V, 0V
S
V
Maximum Output Voltage Swing, High
Maximum Output Voltage Swing, Low
Maximum Output Voltage Swing, High
Maximum Output Voltage Swing, Low
Common Mode Rejection Ratio
V = ±5V, R = 100k
3.9
3.7
4.2
V
V
V
OUTH
S
L
V = ±5V, R = 100k
S
L
V = 5V, 0V; R = 100k
4.2
S
L
V
V
V
V = ±5V, R = 100k
–3.9
–3.7
–4.2
V
V
V
OUTL
OUTH
OUTL
S
L
V = ±5V, R = 100k
S
L
V = 5V, 0V; R = 100k
0.8
3.6
S
L
V = ±5V, R = 150Ω
3.4
3.2
V
V
V
S
L
V = ±5V, R = 150Ω
S
L
V = 5V, 0V; R = 150Ω
3.6
S
L
V = ±5V, R = 150Ω
–3.4
–3.2
–3.6
V
V
V
S
L
V = ±5V, R = 150Ω
●
●
S
L
V = 5V, 0V; R = 150Ω
0.6
52
10
S
L
CMRR
–I
V
= ±3.5V
42
dB
CM
Inverting Input Current
Common Mode Rejection
V
V
= ±3.5V
= ±3.5V
16
22
µA/V
µA/V
CMRR
CM
CM
●
●
–
–
PSRR
Power Supply Rejection Ratio
V = ±2V to ±5V, EN = V
S
56
70
1
dB
+I
Noninverting Input Current
Power Supply Rejection
V = ±2V to ±5V, EN = V
S
2
3
µA/V
µA/V
PSRR
●
●
–
–I
Inverting Input Current
Power Supply Rejection
V = ±2V to ±5V, EN = V
S
2
7
µA/V
PSRR
A
Large-Signal Voltage Gain
V
V
= ±2V, R = 150Ω
50
40
80
65
dB
kΩ
mA
mA
µA
V
OUT
OUT
L
–
R
Transimpedance, ∆V /∆I
= ±2V, R = 150Ω
100
OL
OUT IN
L
I
I
Maximum Output Current
Supply Current per Amplifier
Disable Supply Current per Amplifier
Enable Pin Current
R = 0Ω
●
●
●
OUT
S
L
V
= 0V
4.6
0.1
30
6.5
OUT
EN Pin Voltage = 4.5V, R = 150Ω
100
L
I
110
200
µA
µA
EN
●
SR
Slew Rate (Note 6)
A = 10, R = 150Ω
500
800
30
V/µs
ns
V
L
t
t
Turn-On Delay Time (Note 7)
Turn-Off Delay Time (Note 7)
Small-Signal Rise and Fall Time
Propagation Delay
R = R = 324Ω, R = 100Ω
75
ON
F
G
L
R = R = 324Ω, R = 100Ω
40
100
ns
OFF
F
G
L
t , t
r
R = R = 324Ω, R = 100Ω, V
= 1V
= 1V
= 1V
1.3
2.5
10
ns
f
F
G
L
OUT
OUT
OUT
P-P
P-P
P-P
t
R = R = 324Ω, R = 100Ω, V
ns
PD
F
G
L
os
Small-Signal Overshoot
Settling Time
R = R = 324Ω, R = 100Ω, V
%
F
G
L
t
0.1%, A = –1, R = R = 309Ω, R = 150Ω
25
ns
S
V
F
G
L
dG
dP
Differential Gain (Note 8)
Differential Phase (Note 8)
R = R = 324Ω, R = 150Ω
0.13
0.10
%
F
G
L
R = R = 324Ω, R = 150Ω
DEG
F
G
L
3
LT1398/LT1399/LT1399HV
(LT1399HV)
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 = ±7.5V, EN = 0V, pulse tested, unless otherwise noted. (Note 4)
SYMBOL PARAMETER
Input Offset Voltage
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
1.5
10
12
mV
mV
●
●
∆V /∆T Input Offset Voltage Drift
15
10
µV/°C
OS
+
I
Noninverting Input Current
25
30
µA
µA
IN
●
●
–
I
Inverting Input Current
10
50
60
µA
µA
IN
e
Input Noise Voltage Density
f = 1kHz, R = 1k, R = 10Ω, R = 0Ω, V = ±5V
4.5
6
nV/√Hz
pA/√Hz
pA/√Hz
MΩ
n
F
G
S
S
+i
–i
Noninverting Input Noise Current Density f = 1kHz, V = ±5V
S
n
Inverting Input Noise Current Density
Input Resistance
f = 1kHz, V = ±5V
25
1
n
IN
IN
S
R
V
= ±6V
●
0.3
IN
C
Input Capacitance
Amplifier Enabled
Amplifier Disabled
2.0
2.5
pF
pF
C
V
Output Capacitance
Amplifier Disabled
8.5
pF
OUT
Input Voltage Range, High
V = ±7.5V
●
●
6
6.5
6.5
V
V
INH
S
V = 7.5V, 0V
S
V
V
Input Voltage Range, Low
V = ±7.5V
–6
–6.5
1.0
V
V
INL
S
V = 7.5V, 0V
S
Maximum Output Voltage Swing, High
V = ±7.5V, R = 100k
6.4
6.1
6.7
V
V
V
OUTH
S
L
V = ±7.5V, R = 100k
●
●
●
S
L
V = 7.5V, 0V; R = 100k
6.7
S
L
V
OUTL
V
OUTH
V
OUTL
Maximum Output Voltage Swing, Low
Maximum Output Voltage Swing, High
Maximum Output Voltage Swing, Low
Common Mode Rejection Ratio
V = ±7.5V, R = 100k
–6.4
–6.1
–6.7
V
V
V
S
L
V = ±7.5V, R = 100k
S
L
V = 7.5V, 0V; R = 100k
0.8
5.8
S
L
V = ±7.5V, R = 150Ω
5.4
5.1
V
V
V
S
L
V = ±7.5V, R = 150Ω
S
L
V = 7.5V, 0V; R = 150Ω
5.8
S
L
V = ±7.5V, R = 150Ω
–5.4
–5.1
–5.8
V
V
V
S
L
V = ±7.5V, R = 150Ω
●
●
S
L
V = 7.5V, 0V; R = 150Ω
0.6
52
10
S
L
CMRR
–I
V
= ±6V
42
dB
CM
Inverting Input Current
Common Mode Rejection
V
V
= ±6V
= ±6V
16
22
µA/V
µA/V
CMRR
CM
CM
●
●
–
–
PSRR
Power Supply Rejection Ratio
V = ±2V to ±7.5V, EN = V
S
56
70
1
dB
+I
Noninverting Input Current
Power Supply Rejection
V = ±2V to ±7.5V, EN = V
S
2
3
µA/V
µA/V
PSRR
●
●
–
–I
Inverting Input Current
Power Supply Rejection
V = ±2V to ±7.5V, EN = V
S
2
7
µA/V
PSRR
A
Large-Signal Voltage Gain
V
V
= ±4.5V, R = 150Ω
50
40
80
65
dB
kΩ
mA
mA
µA
V
OUT
OUT
L
–
R
Transimpedance, ∆V /∆I
= ±4.5V, R = 150Ω
100
OL
OUT IN
L
I
I
Maximum Output Current
Supply Current per Amplifier
Disable Supply Current per Amplifier
Enable Pin Current
R = 0Ω
●
●
●
OUT
S
L
V
= 0V
4.6
0.1
30
7
OUT
EN Pin Voltage = 7V, R = 150Ω
100
L
I
110
200
µA
µA
EN
●
4
LT1398/LT1399/LT1399HV
(LT1399HV)
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 = ±7.5V, EN = 0V, pulse tested, unless otherwise noted. (Note 4)
SYMBOL PARAMETER
SR Slew Rate (Note 6)
CONDITIONS
A = 10, R = 150Ω, V = ±5V
MIN
TYP
800
30
MAX
UNITS
V/µs
ns
500
V
L
S
t
t
Turn-On Delay Time (Note 7)
Turn-Off Delay Time (Note 7)
Small-Signal Rise and Fall Time
R = R = 324Ω, R = 100Ω, V = ±5V
75
ON
F
G
L
S
R = R = 324Ω, R = 100Ω, V = ±5V
40
100
ns
OFF
F
G
L
S
t , t
R = R = 324Ω, R = 100Ω, V
= 1V
= 1V
= 1V
,
,
,
1.3
ns
r
f
F
G
L
OUT
P-P
P-P
P-P
V = ±5V
S
t
Propagation Delay
Small-Signal Overshoot
Settling Time
R = R = 324Ω, R = 100Ω, V
2.5
10
25
ns
%
ns
PD
F
G
L
OUT
V = ±5V
S
os
R = R = 324Ω, R = 100Ω, V
F G L
V = ±5V
S
OUT
t
0.1%, A = –1V, R = R = 309Ω, R = 150Ω,
V F G L
V = ±5V
S
S
dG
dP
Differential Gain (Note 8)
Differential Phase (Note 8)
R = R = 324Ω, R = 150Ω, V = ±5V
0.13
0.10
%
F
G
L
S
R = R = 324Ω, R = 150Ω, V = ±5V
DEG
F
G
L
S
Note 1: Absolute Maximum Ratings are those values beyond which the life
Note 6: Slew rate is measured at ±2V on a ±3V output signal.
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
Note 7: Turn-on delay time (tON) is measured from control input to
appearance of 1V at the output, for VIN = 1V. Likewise, turn-off delay
time (tOFF) is measured from control input to appearance of 0.5V on
the output for VIN = 0.5V. This specification is guaranteed by design
and characterization.
voltage and how many amplifiers have their outputs short circuited.
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 4: The LT1398/LT1399/LT1399HV are guaranteed to meet specified
performance from 0°C to 70°C and are designed, characterized and
expected to meet these extended temperature limits, but are not tested at
–40°C and 85°C. Guaranteed I grade parts are available, consult factory.
Note 5: TJ is calculated from the ambient temperature TA and the
power dissipation PD according to the following formula:
LT1398CS, LT1399CS, LT1399HVCS: TJ = TA + (PD • 100°C/W)
LT1399CGN: TJ = TA + (PD • 120°C/W)
W U
TYPICAL AC PERFOR A CE
SMALL SIGNAL
–3dB BW (MHz)
SMALL SIGNAL
0.1dB BW (MHz)
SMALL SIGNAL
PEAKING (dB)
V (V)
S
A
R (Ω)
L
R (Ω)
F
R (Ω)
G
V
±5
±5
±5
1
100
100
100
365
324
309
–
300
300
300
150
150
150
0.05
0
2
324
309
–1
0
5
LT1398/LT1399/LT1399HV
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Closed-Loop Gain vs Frequency
(AV = 1)
Closed-Loop Gain vs Frequency
(AV = 2)
Closed-Loop Gain vs Frequency
(AV = –1)
4
2
10
8
4
2
0
6
0
–2
–4
4
–2
–4
2
1M
VS = ±5V
IN = –10dBm
RF = 365Ω
RL = 100Ω
10M
FREQUENCY (Hz)
100M
1G
1398/99 G01
1M
VS = ±5V
IN = –10dBm
RF = RG = 324Ω
RL = 100Ω
10M
FREQUENCY (Hz)
100M
1G
1398/99 G02
1M
VS = ±5V
10M
FREQUENCY (Hz)
100M
1G
1398/99 G03
V
V
VIN = –10dBm
RF = RG = 309Ω
R
L = 100Ω
Large-Signal Transient Response
(AV = 1)
Large-Signal Transient Response
(AV = 2)
Large-Signal Transient Response
(AV = –1)
1398/99 G04
1398/99 G05
1398/99 G06
VS = ±5V
TIME (5ns/DIV)
VS = ±5V
IN = ±1.25V
RF = RG = 324Ω
RL = 100Ω
TIME (5ns/DIV)
VS = ±5V
IN = ±2.5V
RF = RG = 309Ω
RL = 100Ω
TIME (5ns/DIV)
V
V
VIN = ±2.5V
RF = 365Ω
RL = 100Ω
2nd and 3rd Harmonic Distortion
vs Frequency
Maximum Undistorted Output
Voltage vs Frequency
PSRR vs Frequency
30
8
80
T
= 25°C
G
A
F
L
S
R
R
V
= R = 324Ω
40
50
70
60
50
40
30
20
10
0
= 100Ω
= ±5V
7
6
5
4
3
2
A
= +1
A = +2
V
V
V
= 2VPP
OUT
+PSRR
–PSRR
HD2
60
70
HD3
80
90
T
= 25°C
= 324Ω
= 100Ω
= ±5V
T
= 25°C
A
A
R
R
R
R
= R = 324Ω
F
L
S
F
L
V
G
100
110
= 100Ω
V
A
= +2
1
10
FREQUENCY (MHz)
100
10k
100k
1M
FREQUENCY (Hz)
10M
100M
1
10
100
1000 10000 100000
FREQUENCY (kHz)
1398/1399 G09
1398/1399 G08
1398/1399 G07
6
LT1398/LT1399/LT1399HV
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Input Voltage Noise and Current
Noise vs Frequency
Output Impedance (Disabled)
vs Frequency
Output Impedance vs Frequency
1000
100
100k
10k
1k
100
10
R
A
= 365Ω
= +1
R
R
A
= R = 324Ω
F
V
S
F
L
V
S
G
= 50Ω
= +2
= ±5V
V
= ±5V
V
1
–IN
+IN
EN
10
1
0.1
0.01
100
10 30 100 300 1k 3k 10k 30k 100k
FREQUENCY (Hz)
100k
1M
10M
100M
10k
100k
1M
FREQUENCY (Hz)
10M
100M
FREQUENCY (Hz)
1398/1399 G12
1398/1399 G11
1398/1399 G10
Maximum Capacitive Load
vs Feedback Resistor
Capacitive Load
vs Output Series Resistor
Supply Current vs Supply Voltage
1000
100
10
40
30
20
10
0
6
R
S
= R = 324Ω
F
G
V
= ±5V
5
4
OVERSHOOT < 2%
–
EN = V
EN = 0V
3
2
R
A
= R
G
F
V
S
= +2
1
0
V
= ±5V
PEAKING ≤ 5dB
1
300
900
1500
2100
2700
3300
10
100
CAPACITIVE LOAD (pF)
1000
0
1
2
3
4
5
6
7
8
9
FEEDBACK RESISTANCE (Ω)
SUPPLY VOLTAGE (±V)
1398/1399 G13
1398/1399 G14
1398/1399 G15
Output Voltage Swing
vs Temperature
Enable Pin Current
vs Temperature
Positive Supply Current per
Amplifier vs Temperature
5
4
–10
–20
5.00
V
S
= ±5V
V
S
= ±5V
EN = –5V
4.75
4.50
R
L
= 100k
R
L
= 150Ω
3
EN = 0V
EN = 0
2
–30
–40
–50
–60
–70
4.25
4.00
3.75
3.50
3.25
1
0
EN = –5V
–1
–2
–3
–4
–5
R
L
= 100k
R
L
= 150Ω
–80
3.00
–50
0
25
50
75 100 125
–25
50
100 125
–25
0
50
75 100 125
–50 –25
0
25
75
–50
25
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
1398/1399 G16
1398/1399 G17
1398/1399 G18
7
LT1398/LT1399/LT1399HV
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TYPICAL PERFOR A CE CHARACTERISTICS
Input Offset Voltage
vs Temperature
Input Bias Currents
vs Temperature
3.0
2.5
2.0
1.5
1.0
0.5
0
15
12
V
S
= ±5V
V
S
= ±5V
+
I
B
9
6
3
–
I
B
0
–3
–0.5
–1.0
–6
–25
0
50
75 100 125
50
100 125
–50
25
–50
25
75
–25
0
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
1398/1399 G19
1398/99 G20
All Hostile Crosstalk
All Hostile Crosstalk (Disabled)
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
R = R = 324Ω
R = R = 324Ω
F
L
V
G
F
L
V
G
R
= 100Ω
R
= 100Ω
A
= +2
R
G
B
A
= +2
R
G
B
100k
1M
10M
100M 500M
100k
1M
10M
100M 500M
FREQUENCY (Hz)
FREQUENCY (Hz)
1398/1399 G21
1398/1399 G24
Propagation Delay
Rise Time and Overshoot
OS = 10%
INPUT
100mV/DIV
VOUT
200mV/DIV
OUTPUT
200mV/DIV
1398/1399 G22
1398/1399 G23
tPD = 2.5ns
tr = 1.3ns
A
V = +2
TIME (500ps/DIV)
A
V = +2
TIME (500ps/DIV)
RL = 100Ω
RL = 100Ω
RF = RG = 324Ω
RF = RG = 324Ω
8
LT1398/LT1399/LT1399HV
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PIN FUNCTIONS
LT1398
LT1399, LT1399HV
–IN A (Pin 1): Inverting Input of A Channel Amplifier.
+IN A (Pin 2): Noninverting Input of A Channel Amplifier.
GND (Pins 3, 4, 5, 6): Ground. Not connected internally.
+IN B (Pin 7): Noninverting Input of B Channel Amplifier.
–IN B (Pin 8): Inverting Input of B Channel Amplifier.
EN B (Pin 9): B Channel Enable Pin. Logic low to enable.
OUT B (Pin 10): B Channel Output.
V– (Pin 11): Negative Supply Voltage, Usually –5V.
GND (Pins 12, 13): Ground. Not connected internally.
V+ (Pin 14): Positive Supply Voltage, Usually 5V.
OUT A (Pin 15): A Channel Output.
–IN R (Pin 1): Inverting Input of R Channel Amplifier.
+IN R (Pin 2): Noninverting Input of R Channel Amplifier.
GND (Pin 3): Ground. Not connected internally.
–IN G (Pin 4): Inverting Input of G Channel Amplifier.
+IN G (Pin 5): Noninverting Input of G Channel Amplifier.
GND (Pin 6): Ground. Not connected internally.
+IN B (Pin 7): Noninverting Input of B Channel Amplifier.
–IN B (Pin 8): Inverting Input of B Channel Amplifier.
EN B (Pin 9): B Channel Enable Pin. Logic low to enable.
OUT B (Pin 10): B Channel Output.
V– (Pin 11): Negative Supply Voltage, Usually –5V.
EN A (Pin 16): A Channel Enable Pin. Logic low to enable.
OUT G (Pin 12): G Channel Output.
EN G (Pin 13): G Channel Enable Pin. Logic low to enable.
V+ (Pin 14): Positive Supply Voltage, Usually 5V.
OUT R (Pin 15): R Channel Output.
EN R (Pin 16): R Channel Enable Pin. Logic low to enable.
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PPLICATI
A
S I FOR ATIO
Take care to minimize the stray capacitance between the
output and the inverting input. Capacitance on the invert-
ing input to ground will cause peaking in the frequency
response (and overshoot in the transient response).
Feedback Resistor Selection
The small-signal bandwidth of the LT1398/LT1399/
LT1399HVissetbytheexternalfeedbackresistorsandthe
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
LT1398/LT1399 have been optimized for ±5V supply
operationandhavea–3dBbandwidthof300MHzatagain
of 2. The LT1399HV provides performance similar to the
LT1399. Please refer to the resistor selection guide in the
Typical AC Performance table.
Capacitive Loads
The LT1398/LT1399/LT1399HV can drive many capaci-
tive 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.
Capacitance on the Inverting Input
Current feedback amplifiers require resistive feedback
from the output to the inverting input for stable operation.
9
LT1398/LT1399/LT1399HV
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PPLICATI
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A
will remain enabled at all times, then the EN pin should be
tied to the V– supply. The enable pin current is approxi-
mately 30µA when activated. If using CMOS open-drain
logic, an external 1k pull-up resistor is recommended to
ensure that the LT1399 remains disabled in spite of any
CMOS drain-leakage currents.
Power Supplies
The LT1398/LT1399 will operate from single or split
supplies from ±2V (4V total) to ±6V (12V total). The
LT1399HV will operate from single or split supplies from
±2V (4V total) to ±7.5V (15V 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 600µV per volt of supply mis-
match. The inverting bias current will typically change
about 2µA per volt of supply mismatch.
5.0
T
= 25°C
A
+
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
V
= 5V
–
V
= 0V
–
V
= –5V
Slew Rate
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 ampli-
fier,boththeinputstageandtheoutputstagehaveslewrate
limitations.Intheinvertingmode,andforgainsof2ormore
inthenoninvertingmode,thesignalamplitudebetweenthe
input pins is small and the overall slew rate is that of the
outputstage.Forgainslessthan2inthenoninvertingmode,
the overall slew rate is limited by the input stage.
0
2
3
+
4
5
6
7
1
V
– V (V)
EN
1398/99 F01
Figure 1. +IS vs (V+ – VEN
)
OUTPUT
The input slew rate of the LT1398/LT1399/LT1399HV is
approximately 600V/µs and is set by internal currents and
capacitances.Theoutputslewrateissetbythevalueofthe
feedback resistor and internal capacitance. At a gain of 2
with 324Ω 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.
EN
1398/99 F02
VS = ±5V RF = 324Ω
IN = 1V G = 324Ω
RL = 100Ω
V
R
Enable/ Disable
Figure 2. Amplifier Enable Time, AV = 2
Each amplifier of the LT1398/LT1399/LT1399HV has a
unique high impedance, zero supply current mode which
is controlled by its own EN pin. These amplifiers are
designed to operate with CMOS logic; the amplifiers draw
zero current when these pins are high. To activate each
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
OUTPUT
EN
1398/99 F03
VS = ±5V RF = 324Ω
VIN = 1V RG = 324Ω
RL = 100Ω
Figure 3. Amplifier Disable Time, AV = 2
10
LT1398/LT1399/LT1399HV
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The enable/disable times are very fast when driven from
standard 5V CMOS logic. Each amplifier enables in about
30ns (50% point to 50% point) while operating on ±5V
supplies (Figure 2). Likewise, the disable time is approxi-
mately 40ns (50% point to 50% point) (Figure 3).
EN A
EN B
OUTPUT
Differential Input Signal Swing
To avoid any breakdown condition on the input transis-
tors, thedifferentialinputswingmustbelimitedto±5V. In
normal operation, the differential voltage between the
input pins is small, so the ±5V limit is not an issue. In the
disabled mode however, the differential swing can be the
same as the input swing, and there is a risk of device
breakdown if input voltage range has not been properly
considered.
1398/99 F05
VS = ±5V
INA = VINB = 2VP-P
at 3.58MHz
20ns/DIV
V
Figure 5. 3-Input Video MUX Switching Response (AV = 2)
Using the LT1399 to Drive LCD Displays
Driving the current crop of XGA and UXGA LCD displays
can be a difficult problem because they require drive
voltagesofupto12V, areusuallyacapacitiveloadofover
300pF, and require fast settling. The LT1399HV is par-
ticularly well suited for driving these LCD displays be-
cause it is capable of swinging more than ±6V on ±7.5V
supplies, and it can drive large capacitive loads with a
small series resistor at the output, minimizing settling
time. As seen in Figures 6 and 7, at a gain of +3 with a
16.9Ω output series resistor and a 330pF load, the
LT1399HV is capable of settling to 0.1% in 30ns for a 6V
step. Similarly, a 12V output step settles in 70ns.
3-Input Video MUX Cable Driver
The application on the first page of this data sheet shows
a low cost, 3-input video MUX cable driver. The scope
photo below (Figure 4) displays the cable output of a
30MHz square wave driving 150Ω. In this circuit the
active amplifier is loaded by the sum of RF and RG of each
disabled amplifier. Resistor values have been chosen to
keep the total back termination at 75Ω while maintaining
a gain of 1 at the 75Ω load. The switching time between
any two channels is approximately 32ns when both
enable pins are driven.
When building the board, care was taken to minimize
tracelengthsattheinvertinginput. Thegroundplanewas
also pulled away from RF and RG on both sides of the
board to minimize stray capacitance.
VIN
VOUT
OUTPUT
200mV/DIV
1398/99 AI06
VS = ±5V
20ns/DIV
RF = 324Ω
R
G = 162Ω
RS = 16.9Ω
CL = 330pF
Figure 6. LT1399/LT1399HV Large-Signal Pulse Response
1398/99 F04
RL = 150Ω
5ns/DIV
RF = RG = 324Ω
f = 10MHz
Figure 4. Square Wave Response
11
LT1398/LT1399/LT1399HV
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PPLICATI
A
S
I FOR ATIO
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 LT1398 amplifier (A2),
which also sums the weighted G and B inputs to create a
–0.5 • Y output. LT1398 amplifier B1 then takes the
–0.5 • Y output and amplifies it by a gain of –2, resulting
in the Y output. Amplifier A1 is configured in a noninvert-
ing 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.
VIN
VOUT
1398/99 F07
VS = ±7.5V
RF = 324Ω
RG = 162Ω
50ns/DIV
The B input is similar to the R input. It arrives via 75Ω
coax, and is routed to the noninverting input of LT1398
amplifier B2, and to a 2940Ω 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 B2 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 B2 thus
results in the color-difference output B-Y.
R
S = 16.9Ω
CL = 330pF
Figure 7. LT1399HV Output Voltage Swing
Buffered RGB to Color-Difference Matrix
Two LT1398s can be used to create buffered color-
difference signals from RGB inputs (Figure 8). In this
application, the R input arrives via 75Ω coax. It is routed
to the noninverting input of LT1398 amplifier A1 and to
a 1082Ω resistor R8. There is also an 80.6Ω termination
+
75Ω
R8
A1
SOURCES
R-Y
1082Ω
1/2 LT1398
R
–
R1
324Ω
R11
80.6Ω
R9
549Ω
R7
G
B
324Ω
R12
86.6Ω
R10
2940Ω
–
R6
162Ω
R5
R2
324Ω
324Ω
R13
76.8Ω
A2
1/2 LT1398
+
–
B1
Y
1/2 LT1398
+
R4
324Ω
R3
324Ω
–
ALL RESISTORS 1%
= ±5V
B2
B-Y
V
S
1/2 LT1398
1398/99 F08
+
Figure 8. Buffered RGB to Color-Difference Matrix
12
LT1398/LT1399/LT1399HV
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PPLICATI
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The G input also arrives via 75Ω coax and adds its
contributiontotheYsignalviaa549ΩresistorR9, which
is tied to the inverting input of amplifier A2. There is also
an 86.6Ω 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 B1 then inverts and amplifies the signal by 2,
resulting in the Y output.
R10, giving an amplification of –0.37. This results in a
contribution at the output of A2 of 0.37Y – 0.37B.
IfwenowsumthethreecontributionsattheoutputofA2,
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
Buffered Color-Difference to RGB Matrix
The LT1399 can be used to create buffered RGB outputs
from color-difference signals (Figure 9). The R output is
a back-terminated 75Ω signal created using resistor R5
and LT1399 amplifier A1 configured for a gain of +2 via
324Ω 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 cancella-
tion of the Y signal at the amplifier input. The remaining
R signal is then amplified by A1.
Theback-terminationresistorR11thenhalvestheoutput
of A2 resulting in the G output.
R1
1k
Y
R2
1k
R5
75Ω
+
A1
R-Y
R
1/3 LT1399
–
R3
324Ω
The B output is also a back-terminated 75Ω signal
created using resistor R16 and amplifier A3 configured
for a gain of +2 via 324Ω 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 respec-
tively, resulting in cancellation of the Y signal at the
amplifier input. The remaining B signal is then amplified
by A3.
R4
324Ω
R6
205Ω
R11
75Ω
+
A2
R7
1k
G
1/3 LT1399
–
R10
324Ω
R8
316Ω
R9
845Ω
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 contri-
bution 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
B-Y
R12
1k
R16
75Ω
+
A3
R13
1k
B
1/3 LT1399
–
R14
324Ω
ALL RESISTORS 1%
= ±5V
V
S
R15
324Ω
1398/99 F09
Figure 9. Buffered Color-Difference to RGB Matrix
13
LT1398/LT1399/LT1399HV
W
W
SI PLIFIED SCHE ATIC, each amplifier
+
V
–IN
OUT
+IN
EN
–
V
1398/99 SS
14
LT1398/LT1399/LT1399HV
U
Dimensions in inches (millimeters) unless otherwise noted.
PACKAGE DESCRIPTIO
GN Package
16-Lead Plastic SSOP (Narrow 0.150)
(LTC DWG # 05-08-1641)
0.189 – 0.196*
(4.801 – 4.978)
0.009
(0.229)
REF
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
2
3
4
5
6
7
8
0.015 ± 0.004
(0.38 ± 0.10)
× 45°
0.053 – 0.068
(1.351 – 1.727)
0.004 – 0.0098
(0.102 – 0.249)
0.007 – 0.0098
(0.178 – 0.249)
0° – 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.008 – 0.012
(0.203 – 0.305)
0.025
(0.635)
BSC
* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
GN16 (SSOP) 0398
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
S Package
16-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.386 – 0.394*
(9.804 – 10.008)
16
15
14
13
12
11
10
9
0.150 – 0.157**
0.228 – 0.244
(3.810 – 3.988)
(5.791 – 6.197)
5
7
8
1
2
3
4
6
0.010 – 0.020
(0.254 – 0.508)
× 45°
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
0.008 – 0.010
(0.203 – 0.254)
0° – 8° TYP
0.050
(1.270)
TYP
0.014 – 0.019
(0.355 – 0.483)
0.016 – 0.050
0.406 – 1.270
S16 0695
*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 represen-
tation that the interconnection of its circuits as described herein will notinfringe onexisting patent rights.
15
LT1398/LT1399/LT1399HV
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TYPICAL APPLICATI
Single Supply RGB Video Amplifier
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 imped-
ance of 714Ω. The combination of these two inputs gives
anoutputatthecathodeofD2of2•VIN withnoadditional
DC offset. The 75Ω back termination resistor R9 halves
the signal again such that VOUT equals a buffered version
of VIN.
The LT1399 can be used with a single supply voltage of
6V or more to drive ground-referenced RGB video. In
Figure 10, two 1N4148 diodes D1 and D2 have been
placed in series with the output of the LT1399 amplifier
A1 but within the feedback loop formed by resistor R8.
These diodes effectively level-shift A1’s output down-
ward by 2 diodes, allowing the circuit output to swing to
ground.
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
outputdropslowenoughthatthediodesmightotherwise
reverse bias. This means that this circuit works fine for
continuousvideoinput, butwillrequirethatC1chargeup
after a period of inactivity at the input.
Amplifier A1 is used in a positive gain configuration. The
feedbackresistorR8is324Ω.Thegainresistoriscreated
from the parallel combination of R6 and R7, giving a
Thevenin equivalent 80.4Ω 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
5V
C1
4.7µF
V
S
R1
R6
107Ω
6V TO 12V
1000Ω
D1
D2
R9
75Ω
+
V
OUT
1N4148 1N4148
A1
R2
1300Ω
1/3 LT1399
–
R3
160Ω
R8
324Ω
V
IN
1398/99 F10
R4
75Ω
R7
324Ω
R5
2.32Ω
Figure 10. Single Supply RGB Video Amplifier (1 of 3 Channels)
RELATED PARTS
PART NUMBER
LT1203/LT1205
LT1204
DESCRIPTION
COMMENTS
150MHz Video Multiplexers
2:1 and Dual 2:1 MUXs with 25ns Switch Time
Cascadable Enable 64:1 Multiplexing
4-Input Video MUX with Current Feedback Amplifier
140MHz Current Feedback Amplifier
Low Cost Video Amplifiers
LT1227
1100V/µs Slew Rate, Shutdown Mode
LT1252/LT1253/LT1254
LT1259/LT1260
LT1675
Single, Dual and Quad Current Feedback Amplifiers
130MHz Bandwidth, 0.1dB Flatness > 30MHz
2.5ns Switching Time, 250MHz Bandwidth
Dual/Triple Current Feedback Amplifier
Triple 2:1 Buffered Video Mulitplexer
13989f LT/TP 0699 4K • PRINTED IN USA
16 LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
●
●
LINEAR TECHNOLOGY CORPORATION 1998
(408)432-1900 FAX:(408)434-0507 www.linear-tech.com
相关型号：
LT1399IS#TRPBF
LT1399 - Low Cost Dual and Triple 300MHz Current Feedback Amplifiers with Shutdown; Package: SO; Pins: 16; Temperature Range: -40°C to 85°C
Linear
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