LT1210
1
1210fb
For more information www.linear.com/LT1210
Typical applicaTion
DescripTion
1.1A, 35MHz Current
Feedback Amplifier
The LT
®
1210 is a current feedback amplifier with high out-
put current and excellent large-signal characteristics. The
combination of high slew rate, 1.1A output drive and ±15V
operation enables the device to deliver significant power
at frequencies in the 1MHz to 2MHz range. Short-circuit
protection and thermal shutdown ensure the device’s
ruggedness. The LT1210 is stable with large capacitive
loads, and can easily supply the large currents required
by the capacitive loading. A shutdown feature switches
the device into a high impedance and low supply current
mode, reducing dissipation when the device is not in use.
For lower bandwidth applications, the supply current can
be reduced with a single external resistor.
The LT1210 is available in the TO-220 and DD packages for
operation with supplies up to ±15V. For ±5V applications
the device is also available in a low thermal resistance
SO-16 package.
Twisted Pair Driver
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
FeaTures
applicaTions
n 1.1A Minimum Output Drive Current
n 35MHz Bandwidth, AV = 2, RL = 10Ω
n 900V/µs Slew Rate, AV = 2, RL = 10Ω
n High Input Impedance: 10MΩ
n Wide Supply Range: ±5V to ±15V
(TO-220 and DD Packages)
n Enhanced θJA SO-16 Package for ±5V Operation
n Shutdown Mode: IS < 200µA
n Adjustable Supply Current
n Stable with CL = 10,000pF
n Operating Temperature Range: –40°C to 85°C
n Available in 7-Lead DD, TO-220 and
16-Lead SO Packages
n Cable Drivers
n Buffers
n Test Equipment Amplifiers
n Video Amplifiers
n ADSL Drivers
Total Harmonic Distortion vs Frequency
–
+
LT1210
VIN
4.7µF*
4.7µF*
100nF
1210 TA01
RT
11Ω
2.5W T1**
845Ω
31
274Ω
100nF
SD
15V
–15V
* TANTALUM
** MIDCOM 671-7783 OR EQUIVALENT
RL
100Ω
2.5W
+
+
FREQUENCY (Hz)
1k
TOTAL HARMONIC DISTORTION (dB)
–50
–60
–70
–80
–90
–100 10k 100k 1M
1210 TA02
VS = ±15V
VOUT = 20VP-P
AV = 4
RL = 10Ω
RL = 50Ω
RL = 12.5Ω
LT1210
2
1210fb
For more information www.linear.com/LT1210
absoluTe MaxiMuM raTings
Supply Voltage ..................................................... ±18V
Input Current ....................................................... ±15mA
Output Short-Circuit Duration
(Note 2) ..........................................Thermally Limited
Operating Temperature Range (Note 3)
LT1210C ............................................... –40°C to 85°C
LT1210I ................................................ –40°C to 85°C
(Note 1)
R PACKAGE
7-LEAD PLASTIC DD
FRONT VIEW
OUT
V–
COMP
V+
SHUTDOWN
+IN
–IN
7
6
5
4
3
2
1
TAB
IS V+
TJMAX = 150°C, θJA = 25°C/W
TOP VIEW
S PACKAGE
16-LEAD PLASTIC SO
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V+
V+
OUT
V+
NC
–IN
NC
V+
V+
NC
V–
COMP
SHUTDOWN
+IN
NC
V+
TJMAX = 150°C, θJA = 40°C/W (Note 5)
T7 PACKAGE
7-LEAD TO-220
OUT
V–
COMP
V+
SHUTDOWN
+IN
–IN
FRONT VIEW
7
6
5
4
3
2
1
TAB
IS V+
TJMAX = 150°C, θJC = 5°C/W
Specified Temperature Range (Note 4)
LT1210C ................................................... 0°C to 70°C
LT1210I ................................................ –40°C to 85°C
Junction Temperature ........................................ 150°C
Storage Temperature Range ...................–65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
pin conFiguraTion
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1210CR#PBF LT1210CR#TRPBF LT1210R 7-Lead Plastic DDPAK 0°C to 70°C
LT1210IR#PBF LT1210IR#TRPBF LT1210R 7-Lead Plastic DDPAK –40°C to 85°C
LT1210CS#PBF LT1210CS#TRPBF LT1210CS 16-Lead Plastic SOIC 0°C to 70°C
LT1210CT7#PBF N/A LT1210CT7 7-Lead TO-220 0°C to 70°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
orDer inForMaTion
LT1210
3
1210fb
For more information www.linear.com/LT1210
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCM = 0V, ± 5V ≤ VS ≤ ± 15V, pulse tested, VSD = 0V, unless
otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOS Input Offset Voltage
l
±3 ±15
±20
mV
mV
Input Offset Voltage Drift l10 µV/°C
IIN+Noninverting Input Current
l
±2 ±5
±20
µA
µA
IIN–Inverting Input Current
l
±10 ±60
±100
µA
µA
enInput Noise Voltage Density f = 10kHz, RF = 1k, RG = 10Ω, RS = 0Ω 3.0 nV/√Hz
+inInput Noise Current Density f = 10kHz, RF = 1k, RG = 10Ω, RS = 10k 2.0 pA/√Hz
–inInput Noise Current Density f = 10kHz, RF = 1k, RG = 10Ω, RS = 10k 40 pA/√Hz
RIN Input Resistance VIN = ±12V, VS = ±15V
VIN = ±2V, VS = ±5V
l
l
1.50
0.25
10
5
MΩ
MΩ
CIN Input Capacitance VS = ±15V 2 pF
Input Voltage Range VS = ±15V
VS = ±5V
l
l
±12
±2
±13.5
±3.5
V
V
CMRR Common Mode Rejection Ratio VS = ±15V, VCM = ±12V
VS = ±5V, VCM = ±2V
l
l
55
50
62
60
dB
dB
Inverting Input Current
Common Mode Rejection
VS = ±15V, VCM = ±12V
VS = ±5V, VCM = ±2V
l
l
0.1
0.1
10
10
µA/V
µA/V
PSRR Power Supply Rejection Ratio VS = ±5V to ±15V l60 77 dB
Noninverting Input Current
Power Supply Rejection
VS = ±5V to ±15V l30 500 nA/V
Inverting Input Current
Power Supply Rejection
VS = ±5V to ±15V l0.7 5 µA/V
AVLarge-Signal Voltage Gain TA = 25°C, VS = ±15V, VOUT = ±10V,
RL = 10Ω (Note 5)
55 71 dB
VS = ±15V, VOUT = ±8.5V, RL = 10Ω (Note 5) l55 68 dB
VS = ±5V, VOUT = ±2V, RL = 10Ω l55 68 dB
ROL Transresistance, ∆VOUT/∆IIN–TA = 25°C, VS = ±15V, VOUT = ±10V,
RL = 10Ω (Note 5)
100
260
kΩ
VS = ±15V, VOUT = ±8.5V, RL = 10Ω (Note 5) l75 200 kΩ
VS = ±5V, VOUT = ±2V, RL = 10Ω l75 200 kΩ
VOUT Maximum Output Voltage Swing TA = 25°C, VS = ±15V, RL = 10Ω (Note 5)
l
±10.0
±8.5
±11.5 V
V
TA = 25°C, VS = ±5V, RL = 10Ω
l
±2.5
±2.0
±3.0 V
V
IOUT Maximum Output Current (Note 5) VS = ±15V, RL = 1Ω l1.1 2.0 A
ISSupply Current (Note 5) TA = 25°C, VS = ±15V, VSD = 0V
l
35 50
65
mA
mA
Supply Current, RSD = 51k (Notes 5, 6) TA = 25°C, VS = ±15V 15 30 mA
Positive Supply Current, Shutdown VS = ±15V, VSD = 15V l200 µA
Output Leakage Current, Shutdown VS = ±15V, VSD = 15V l10 µA
LT1210
4
1210fb
For more information www.linear.com/LT1210
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCM = 0V, ± 5V ≤ VS ≤ ± 15V, pulse tested, VSD = 0V, unless
otherwise noted.
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: A heat sink may be required to keep the junction temperature
below the Absolute Maximum rating. Applies to short circuits to ground
only. A short circuit between the output and either supply may permanently
damage the part when operated on supplies greater than ±10V.
Note 3: The LT1210C/LT1210I are guaranteed functional over the
temperature range of –40°C to 85°C.
Note 4: The LT1210C is guaranteed to meet specified performance from
0°C to 70°C. The LT1210C is designed, characterized and expected to meet
specified performance from –40°C to 85°C but not tested or QA sampled
at these temperatures. The LT1210I is guaranteed to meet specified
performance from –40°C to 85°C.
Note 5: SO package is recommended for ±5V supplies only, as the power
dissipation of the SO package limits performance on higher supplies.
For supply voltages greater than ±5V, use the TO-220 or DD package.
See “Thermal Considerations” in the Applications Information section for
details on calculating junction temperature. If the maximum dissipation of
the package is exceeded, the device will go into thermal shutdown.
Note 6: RSD is connected between the Shutdown pin and ground.
Note 7: Slew rate is measured at ±5V on a ±10V output signal while
operating on ±15V supplies with RF = 1.5k, RG = 1.5k and RL = 400Ω.
Note 8: NTSC composite video with an output level of 2V.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SR Slew Rate (Note 7)
Slew Rate (Note 5)
TA = 25°C, AV = 2, RL = 400Ω
TA = 25°C, AV = 2, RL = 10Ω
400 900
900
V/µs
V/µs
Differential Gain (Notes 5, 8) VS = ±15V, RF = 750Ω, RG = 750Ω, RL = 15Ω 0.3 %
Differential Phase (Notes 5, 8) VS = ±15V, RF = 750Ω, RG = 750Ω, RL = 15Ω 0.1 DEG
BW Small-Signal Bandwidth AV = 2, VS = ±15V, Peaking ≤ 1dB,
RF = RG = 680Ω, RL = 100Ω
55 MHz
AV = 2, VS = ±15V, Peaking ≤ 1dB,
RF = RG = 576Ω, RL = 10Ω
35 MHz
LT1210
5
1210fb
For more information www.linear.com/LT1210
sMall-signal banDwiDTh
RSD = 0Ω, IS = 30mA, VS = ±5V, Peaking ≤ 1dB
AV
RL
RF
RG
–3dB BW
(MHz)
–1 150
30
10
549
590
619
549
590
619
52.5
39.7
26.5
1 150
30
10
604
649
619
–
–
–
53.5
39.7
27.4
2 150
30
10
562
590
576
562
590
576
51.8
38.8
27.4
10 150
30
10
392
383
215
43.2
42.2
23.7
48.4
40.3
36.0
RSD = 0Ω, IS = 35mA, VS = ±15V, Peaking ≤ 1dB
AV
RL
RF
RG
–3dB BW
(MHz)
–1 150
30
10
604
649
665
604
649
665
66.2
48.4
46.5
1 150
30
10
750
866
845
–
–
–
56.8
35.4
24.7
2 150
30
10
665
715
576
665
715
576
52.5
38.9
35.0
10 150
30
10
453
432
221
49.9
47.5
24.3
61.5
43.1
45.5
RSD = 7.5k, IS = 15mA, VS = ±5V, Peaking ≤ 1dB
AV
RL
RF
RG
–3dB BW
(MHz)
–1 150
30
10
562
619
604
562
619
604
39.7
28.9
20.5
1 150
30
10
634
681
649
–
–
–
41.9
29.7
20.7
2 150
30
10
576
604
576
576
604
576
40.2
29.6
21.6
10 150
30
10
324
324
210
35.7
35.7
23.2
39.5
32.3
27.7
RSD = 47.5k, IS = 18mA, VS = ±15V, Peaking ≤ 1dB
AV
RL
RF
RG
–3dB BW
(MHz)
–1 150
30
10
619
698
698
619
698
698
47.8
32.3
22.2
1 150
30
10
732
806
768
–
–
–
51.4
33.9
22.5
2 150
30
10
634
698
681
634
698
681
48.4
33.0
22.5
10 150
30
10
348
357
205
38.3
39.2
22.6
46.8
36.7
31.3
RSD = 15k, IS = 7.5mA, VS = ±5V, Peaking ≤ 1dB
AV
RL
RF
RG
–3dB BW
(MHz)
–1 150
30
10
536
549
464
536
549
464
28.2
20.0
15.0
1 150
30
10
619
634
511
–
–
–
28.6
19.8
14.9
2 150
30
10
536
549
412
536
549
412
28.3
19.9
15.7
10 150
30
10
150
118
100
16.5
13.0
11.0
31.5
27.1
19.4
RSD = 82.5k, IS = 9mA, VS = ±15V, Peaking ≤ 1dB
AV
RL
RF
RG
–3dB BW
(MHz)
–1 150
30
10
590
649
576
590
649
576
34.8
22.5
16.3
1 150
30
10
715
768
649
–
–
–
35.5
22.5
16.1
2 150
30
10
590
665
549
590
665
549
35.3
22.5
16.8
10 150
30
10
182
182
100
20.0
20.0
11.0
37.2
28.9
22.5
LT1210
6
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For more information www.linear.com/LT1210
Typical perForMance characTerisTics
Bandwidth vs Supply Voltage Bandwidth vs Supply Voltage
Differential Phase vs
Supply Voltage
Differential Gain vs
Supply Voltage
Spot Noise Voltage and Current
vs Frequency
Bandwidth vs Supply Voltage Bandwidth vs Supply Voltage
Bandwidth and Feedback Resistance
vs Capacitive Load for Peaking ≤ 1dB
Bandwidth and Feedback Resistance
vs Capacitive Load for Peaking ≤ 5dB
4
0
10
30
40
50
100
70
812
20
80
90
60
6 10 14 16 18
SUPPLY VOLTAGE (±V)
–3dB BANDWIDTH (MHz)
1210 G01
PEAKING ≤ 1dB
PEAKING ≤ 5dB
RF = 470Ω
RF = 560Ω
RF = 750Ω
RF = 1k
RF = 1.5k
AV = 2
RL = 100Ω
RF = 680Ω
4
0
20
50
812
10
40
30
6 10 14 16 18
SUPPLY VOLTAGE (±V)
–3dB BANDWIDTH (MHz)
1210 G02
PEAKING ≤ 1dB
PEAKING ≤ 5dB
RF = 560Ω
RF = 1k
RF = 2k
RF = 750Ω
AV = 2
RL = 10Ω
CAPACITIVE LOAD (pF)
100
FEEDBACK RESISTANCE (Ω)
1k
10k
100101 10000
1210 G03
1000
BANDWIDTH
FEEDBACK RESISTANCE
AV = 2
RL = ∞
VS = ±15V
CCOMP = 0.01µF 1
10
100
–3dB BANDWIDTH (MHz)
4
0
10
30
40
50
100
70
812
20
80
90
60
6 10 14 16 18
SUPPLY VOLTAGE (±V)
–3dB BANDWIDTH (MHz)
1210 G04
PEAKING ≤ 1dB
PEAKING ≤ 5dB
RF = 470Ω
RF = 1.5k
RF = 330Ω
RF = 680Ω
RF =390Ω
AV = 10
RL = 100Ω
4
0
20
50
812
10
40
30
6 10 14 16 18
SUPPLY VOLTAGE (±V)
–3dB BANDWIDTH (MHz)
1210 G05
PEAKING ≤ 1dB
RF = 560Ω
RF = 1k
RF = 1.5k
AV = 10
RL = 10Ω
RF = 680Ω
CAPACITIVE LOAD (pF)
FEEDBACK RESISTANCE (Ω)
1
1210 G06
10 100 1000 10000
0
–3dB BANDWIDTH (MHz)
1k
10k
0100
10
100
1
FEEDBACK
RESISTANCE
BANDWIDTH
AV = +2
RL = ∞
VS = ±15V
CCOMP = 0.01µF
SUPPLY VOLTAGE (±V)
5
DIFFERENTIAL PHASE (DEG)
0.6
0.5
0.4
0.3
0.2
0.1
013
1210 G07
7911 15
RF = RG = 750Ω
AV = 2
RL = 10Ω
RL = 50Ω
RL = 15Ω
RL = 30Ω
SUPPLY VOLTAGE (±V)
5
DIFFERENTIAL GAIN (%)
0.5
0.4
0.3
0.2
0.1
013
1210 G08
7911 15
RF = RG = 750Ω
AV = 2
RL = 10Ω
RL = 15Ω
RL = 30Ω
RL = 50Ω
FREQUENCY (Hz)
10
1
10
100
100 100k
1210 G09
1k 10k
SPOT NOISE (nV/√Hz OR pA/√Hz)
en
–in
+in
LT1210
7
1210fb
For more information www.linear.com/LT1210
Typical perForMance characTerisTics
Supply Current vs
Shutdown Pin Current
Input Common Mode Limit vs
Junction Temperature
Output Short-Circuit Current vs
Junction Temperature
Output Saturation Voltage vs
Junction Temperature
Power Supply Rejection Ratio
vs Frequency
Supply Current vs Large-Signal
Output Frequency (No Load)
Supply Current vs Supply Voltage
Supply Current vs
Ambient Temperature, VS = ± 5V
Supply Current vs
Ambient Temperature, VS = ±15V
4812
40
38
36
34
32
30
28
26
24
22
20 6 10 14 16 18
SUPPLY VOLTAGE (±V)
SUPPLY CURRENT (mA)
1210 G10
TA = 25°C
TA = 85°C
TA = 125°C
RSD = 0Ω
TA = –40°C
TEMPERATURE (°C)
–50
SUPPLY CURRENT (mA)
40
35
30
25
20
15
10
5
0050 75
1210 G11
–25 25 100 125
AV = 1
RL = ∞
RSD = 0Ω
RSD = 7.5k
RSD = 15k
TEMPERATURE (°C)
–50
SUPPLY CURRENT (mA)
40
35
30
25
20
15
10
5
0050 75
1210 G12
–25 25 100 125
AV = 1
RL = ∞
RSD = 0Ω
RSD = 47.5k
RSD = 82.5k
SHUTDOWN PIN CURRENT (µA)
0
SUPPLY CURRENT (mA)
40
35
30
25
20
15
10
5
0400
1210 G13
100 200 300 500
VS = ±15V
TEMPERATURE (°C)
–50
V–
COMMON MODE RANGE (V)
0.5
1.5
2.0
–2.0
75
V+
1210 G14
1.0
0 125
–1.5
–1.0
–0.5
50
–25 100
25
TEMPERATURE (°C)
–50
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6 25 75
1210 G15
–25 0 50 100 125
OUTPUT SHORT-CIRCUIT CURRENT (A)
SOURCING
SINKING
TEMPERATURE (°C)
–50
OUTPUT SATURATION VOLTAGE (V)
4
3
2
1
V–
75
V+
–1
–2
–3
–4
1210 G16
0 125
50
–25 100
25
VS = ±15V RL = 2k
RL = 10Ω
RL = 10Ω
RL = 2k
FREQUENCY (Hz)
20
POWER SUPPLY REJECTION (dB)
40
60
70
10k 1M 10M 100M
1210 G17
0100k
50
30
10
RL = 50Ω
VS = ±15V
RF = RG = 1k
NEGATIVE
POSITIVE
FREQUENCY (Hz)
10k
SUPPLY CURRENT (mA)
100
90
80
70
60
50
40
30
20 100k 1M 10M
1210 G18
AV = 2
RL = ∞
VS = ±15V
VOUT = 20VP-P
LT1210
8
1210fb
For more information www.linear.com/LT1210
Typical perForMance characTerisTics
3rd Order Intercept vs Frequency Test Circuit for 3rd Order Intercept
Output Impedance vs Frequency
Output Impedance in Shutdown
vs Frequency
Large-Signal Voltage Gain vs
Frequency
FREQUENCY (Hz)
OUTPUT IMPEDANCE (Ω)
100
10
1
0.1
0.01
100k 10M 100M
1210 G19
1M
VS = ±15V
IO = 0mA
RSD = 82.5k
RSD = 0Ω
FREQUENCY (Hz)
OUTPUT IMPEDANCE (Ω)
10k
1k
100
10
1
100k 10M 100M
1210 G20
1M
FREQUENCY (Hz)
LARGE-SIGNAL VOLTAGE GAIN (dB)
18
15
12
9
6
3
0
103105107
1210 G21
104106108
AV = 4, RL = 10Ω
RF = 680Ω, RG = 220Ω
VS = ±15V, VIN = 5VP-P
FREQUENCY (MHz)
0
3RD ORDER INTERCEPT (dBm)
24 6 8
1210 G22
10
56
54
52
50
48
46
44
42
40
VS = ±15V
RL = 10Ω
RF = 680Ω
RG = 220Ω
–
+
10Ω
LT1210
1210 TC01
220Ω
680Ω
PO
MEASURE INTERCEPT AT PO
LT1210
9
1210fb
For more information www.linear.com/LT1210
applicaTions inForMaTion
The LT1210 is a current feedback amplifier with high output
current drive capability. The device is stable with large
capacitive loads and can easily supply the high currents
required by capacitive loads. The amplifier will drive low
impedance loads such as cables with excellent linearity
at high frequencies.
Feedback Resistor Selection
The optimum value for the feedback resistors is a function
of the operating conditions of the device, the load imped-
ance and the desired flatness of response. The Typical AC
Performance tables give the values which result in less than
1dB of peaking for various resistive loads and operating
conditions. If this level of flatness is not required, a higher
bandwidth can be obtained by use of a lower feedback
resistor. The characteristic curves of Bandwidth vs Supply
Voltage indicate feedback resistors for peaking up to 5dB.
These curves use a solid line when the response has less
than 1dB of peaking and a dashed line when the response
has 1dB to 5dB of peaking. The curves stop where the
response has more than 5dB of peaking.
For resistive loads, the COMP pin should be left open (see
Capacitive Loads section).
Capacitive Loads
The LT1210 includes an optional compensation network
for driving capacitive loads. This network eliminates most
of the output stage peaking associated with capacitive
loads, allowing the frequency response to be flattened.
Figure 1 shows the effect of the network on a 200pF load.
Without the optional compensation, there is a 6dB peak
at 40MHz caused by the effect of the capacitance on the
output stage. Adding a 0.01µF bypass capacitor between
the output and the COMP pins connects the compensation
and greatly reduces the peaking. A lower value feedback
resistor can now be used, resulting in a response which
is flat to ±1dB to 40MHz. The network has the greatest
effect for CL in the range of 0pF to 1000pF. The graphs of
Bandwidth and Feedback Resistance vs Capacitive Load
can be used to select the appropriate value of feedback
resistor. The values shown are for 1dB and 5dB peaking
at a gain of 2 with no resistive load. This is a worst-case
condition, as the amplifier is more stable at higher gains
and with some resistive load in parallel with the capacitance.
Also shown is the –3dB bandwidth with the suggested
feedback resistor vs the load capacitance.
Although the optional compensation works well with ca-
pacitive loads, it simply reduces the bandwidth when it is
connected with resistive loads. For instance, with a 10Ω
load, the bandwidth drops from 35MHz to 26MHz when the
compensation is connected. Hence, the compensation was
made optional. To disconnect the optional compensation,
leave the COMP pin open.
Shutdown/Current Set
If the shutdown feature is not used, the SHUTDOWN pin
must be connected to ground or V–.
The Shutdown pin can be used to either turn off the bias-
ing for the amplifier, reducing the quiescent current to
less than 200µA, or to control the quiescent current in
normal operation.
The total bias current in the LT1210 is controlled by the
current flowing out of the Shutdown pin. When the Shut-
down pin is open or driven to the positive supply, the part
is shut down. In the shutdown mode, the output looks
like a 70pF capacitor and the supply current is typically
less than 100µA. The Shutdown pin is referenced to the
positive supply through an internal bias circuit (see the
Simplified Schematic). An easy way to force shutdown is
to use open-drain (collector) logic. The circuit shown in
Figure 2 uses a 74C904 buffer to interface between 5V
logic and the LT1210. The switching time between the
active and shutdown states is about 1µs.
A 24k pull-up
Figure 1
FREQUENCY (MHz)
1
–6
VOLTAGE GAIN (dB)
–2
2
6
10
10 100
1210 F01
–4
0
4
8
12
14
VS = ±15V
CL = 200pF
RF = 1.5k
COMPENSATION
RF = 3.4k
NO COMPENSATION
RF = 3.4k
COMPENSATION
LT1210
10
1210fb
For more information www.linear.com/LT1210
applicaTions inForMaTion
resistor speeds up the turn-off time and ensures that
the LT1210 is completely turned off. Because the pin is
referenced to the positive supply, the logic used should
have a breakdown voltage of greater than the positive
supply voltage. No other circuitry is necessary as the
internal circuit limits the Shutdown pin current to about
500µA. Figure 3 shows the resulting waveforms.
For applications where the full bandwidth of the amplifier
is not required, the quiescent current of the device may be
reduced by connecting a resistor from the Shutdown pin
to ground. The quiescent current will be approximately 65
times the current in the Shutdown pin. The voltage across
the resistor in this condition is V+ – 3VBE. For example, a
82k resistor will set the quiescent supply current to 9mA
with VS = ±15V.
The photos in Figures 4a and 4b show the effect of re-
ducing the quiescent supply current on the large-signal
response. The quiescent current can be reduced to 9mA
in the inverting configuration without much change in
response. In noninverting mode, however
, the slew rate
is reduced as the quiescent current is reduced.
Slew Rate
Unlike a traditional op amp, the slew rate of a current
feedback amplifier is not independent of the amplifier gain
configuration. There are slew rate limitations in both the
input stage and the output stage. In the inverting mode,
and for higher gains in the noninverting mode, the signal
amplitude on the input pins is small and the overall slew
rate is that of the output stage. The input stage slew rate
is related to the quiescent current and will be reduced as
the supply current is reduced. The output slew rate is set
by the value of the feedback resistors and the internal
capacitance. Larger feedback resistors will reduce the slew
rate as will lower supply voltages, similar to the way the
Figure 2. Shutdown Interface
–
+
LT1210
SD
15V
–15V
RF
RG
VIN
5V
24k
ENABLE
VOUT
1210 F02
15V
74C906
Figure 3. Shutdown Operation
AV = 1
RF = 825Ω
RL = 50Ω
RPULL-UP = 24k
VIN = 1VP-P
VS = ±15V
1210 F03
VOUT
ENABLE
Figure 4a. Large-Signal Response vs IQ, AV = –1
Figure 4b. Large-Signal Response vs IQ, AV = 2
RF = 750Ω
RL = 10Ω
IQ = 9mA, 18mA, 36mA
VS = ±15V
1210 F04a
RF = 750Ω
RL = 10Ω
IQ = 9mA, 18mA, 36mA
VS = ±15V
1210 F04b
LT1210
11
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For more information www.linear.com/LT1210
applicaTions inForMaTion
bandwidth is reduced. The photos in Figures 5a, 5b and 5c
show the large-signal response of the LT1210 for various
gain configurations. The slew rate varies from 770V/µs
for a gain of 1, to 1100V/µs for a gain of –1.
When the LT1210 is used to drive capacitive loads, the
available output current can limit the overall slew rate.
In the fastest configuration, the LT1210 is capable of a
slew rate of over 1V/ns. The current required to slew a
capacitor at this rate is 1mA per picofarad of capacitance,
so 10,000pF would require 10A! The photo (Figure 6)
shows the large-signal behavior with CL = 10,000pF. The
slew rate is about 150V/µs, determined by the current
limit of 1.5A.
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
input pins is small, so this clamp has no effect; however,
in the shutdown mode the differential swing can be the
same as the input swing. The clamp voltage will then set
the maximum allowable input voltage. To allow for some
margin, it is recommended that the input signal be less
than ±5V when the device is shut down.
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), but it does not
degrade the stability of the amplifier.
Figure 5a. Large-Signal Response, AV = 1
Figure 5b. Large-Signal Response, AV = –1
Figure 5c. Large-Signal Response, AV = 2
Figure 6. Large-Signal Response, CL = 10,000pF
RF = 825Ω
RL = 10Ω
VS = ±15V 1210 F05a
RF = RG = 750Ω
RL = 10Ω
VS = ±15V 1210 F05b
RF = RG = 750Ω
RL = 10Ω
VS = ±15V 1210 F05c
RF = RG = 3k
RL = ∞
VS = ±15V 1210 F06
LT1210
12
1210fb
For more information www.linear.com/LT1210
applicaTions inForMaTion
Power Supplies
The LT1210 will operate from single or split supplies from
±5V (10V 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
less than 0.5µA per volt.
Power Supply Bypassing
To obtain the maximum output and the minimum distor-
tion from the LT1210, the power supply rails should be
well bypassed. For example, with the output stage pour-
ing 1A current peaks into the load, a 1Ω power supply
impedance will cause a droop of 1V, reducing the available
output swing by that amount. Surface mount tantalum
and ceramic capacitors make excellent low ESR bypass
elements when placed close to the chip. For frequencies
above 100kHz, use 1µF and 100nF ceramic capacitors.
If significant power must be delivered below 100kHz,
capacitive reactance becomes the limiting factor. Larger
ceramic or tantalum capacitors, such as 4.7µF, are recom-
mended in place of the 1µF unit mentioned above.
Inadequate bypassing is evidenced by reduced output
swing and “distorted” clipping effects when the output is
driven to the rails. If this is observed, check the supply
pins of the device for ripple directly related to the output
waveform. Significant supply modulation indicates poor
bypassing.
Thermal Considerations
The LT1210 contains a thermal shutdown feature which
protects against excessive internal (junction) temperature.
If the junction temperature of the device exceeds the pro-
tection threshold, the device will begin cycling between
normal operation and an off state. The cycling is not
harmful to the part. The thermal cycling occurs at a slow
rate, typically 10ms to several seconds, which depends
on the power dissipation and the thermal time constants
of the package and heat sinking. Raising the ambient
temperature until the device begins thermal shutdown
gives a good indication of how much margin there is in
the thermal design.
For surface mount devices heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Experiments have shown that the
heat spreading copper layer does not need to be electri-
cally connected to the tab of the device. The PCB material
can be very effective at transmitting heat between the pad
area attached to the tab of the device, and a ground or
power plane layer either inside or on the opposite side of
the board. Although the actual thermal resistance of the
PCB material is high, the length/area ratio of the thermal
resistance between the layer is small. Copper board stiffen-
ers and plated through holes can also be used to spread
the heat generated by the device.
Tables 1 and 2 list thermal resistance for each package.
For the TO-220 package, thermal resistance is given for
junction-to-case only since this package is usually mounted
to a heat sink. Measured values of thermal resistance for
several different board sizes and copper areas are listed
for each surface mount package. All measurements were
taken in still air on 3/32" FR-4 board with 2 oz copper. This
data can be used as a rough guideline in estimating thermal
resistance. The thermal resistance for each application will
be affected by thermal interactions with other components
as well as board size and shape.
Table 1. R Package, 7-Lead DD
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
TOPSIDE* BACKSIDE
2500 sq. mm 2500 sq. mm 2500 sq. mm 25°C/W
1000 sq. mm 2500 sq. mm 2500 sq. mm 27°C/W
125 sq. mm 2500 sq. mm 2500 sq. mm 35°C/W
*Tab of device attached to topside copper
Table 2. Fused 16-Lead SO Package
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
TOPSIDE* BACKSIDE
2500 sq. mm 2500 sq. mm 5000 sq. mm 40°C/W
1000 sq. mm 2500 sq. mm 3500 sq. mm 46°C/W
600 sq. mm 2500 sq. mm 3100 sq. mm 48°C/W
180 sq. mm 2500 sq. mm 2680 sq. mm 49°C/W
180 sq. mm 1000 sq. mm 1180 sq. mm 56°C/W
180 sq. mm 600 sq. mm 780 sq. mm 58°C/W
180 sq. mm 300 sq. mm 480 sq. mm 59°C/W
180 sq. mm 100 sq. mm 280 sq. mm 60°C/W
180 sq. mm 0 sq. mm 180 sq. mm 61°C/W
LT1210
13
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For more information www.linear.com/LT1210
applicaTions inForMaTion
T7 Package, 7-Lead TO-220
Thermal Resistance (Junction-to-Case) = 5°C/W
Calculating Junction Temperature
The junction temperature can be calculated from the
equation:
TJ = (PD)(θJA) + TA
where:
TJ = Junction Temperature
TA = Ambient Temperature
PD = Device Dissipation
θJA = Thermal Resistance (Junction-to-Ambient)
As an example, calculate the junction temperature for the
circuit in Figure 7 for the SO and R packages assuming a
70°C ambient temperature.
The device dissipation can be found by measuring the
supply currents, calculating the total dissipation and
then subtracting the dissipation in the load and feedback
network.
PD = (76mA)(10V) – (1.4V)2/ 10 = 0.56W
Figure 7
then:
TJ = (0.56W)(46°C/W) + 70°C = 96°C
for the SO package with 1000 sq. mm topside
heat sinking
TJ = (0.56W)(27°C/W) + 70°C = 85°C
for the R package with 1000 sq. mm topside heat
sinking
Since the maximum junction temperature is 150°C,
both packages are clearly acceptable.
–
+
LT1210 SD
5V
–5V 680Ω
220Ω
10Ω
0V
2V
VO
VO = 1.4VRMS
76mA
1210 F07
–2V
A
LT1210
14
1210fb
For more information www.linear.com/LT1210
Typical applicaTions
Precision × 10 High Current Amplifier CMOS Logic to Shutdown Interface
–
+
LT1097
–
+
LT1210
VIN
SD
COMP
0.01µF
3k
330Ω
9.09k
1k
OUT
OUTPUT OFFSET: <500µV
SLEW RATE: 2V/µs
BANDWIDTH: 4MHz
STABLE WITH CL < 10nF
1210 TA03
500pF
–
+
LT1210
SD
–15V
15V
24k
10k
5V
2N3904
1210 TA04
Distribution Amplifier Buffer AV = 1
–
+
LT1210
SD
75Ω
VIN
RF
RG
75Ω
75Ω
75Ω
75Ω
75Ω CABLE
1210 TA05
–
+
LT1210
SD 0.01µF*
VOUT
RF**
VIN
1210 TA06
* OPTIONAL, USE WITH CAPACITIVE LOADS
** VALUE OF RF DEPENDS ON SUPPLY
VOLTAGE AND LOADING. SELECT
FROM TYPICAL AC PERFORMANCE
TABLE OR DETERMINE EMPIRICALLY
COMP
LT1210
16
1210fb
For more information www.linear.com/LT1210
package DescripTion
Please refer to http://www.linear.com/product/LT1210#packaging for the most recent package drawings.
R (DD7) 0212 REV F
.026 – .035
(0.660 – 0.889)
TYP
.143 +.012
–.020
( )
3.632+0.305
–0.508
.050
(1.27)
BSC
.013 – .023
(0.330 – 0.584)
.095 – .115
(2.413 – 2.921)
.004 +.008
–.004
( )
0.102+0.203
–0.102
.050 ±.012
(1.270 ±0.305)
.059
(1.499)
TYP
.045 – .055
(1.143 – 1.397)
.165 – .180
(4.191 – 4.572)
.330 – .370
(8.382 – 9.398)
.060
(1.524)
TYP
.390 – .415
(9.906 – 10.541)
15° TYP
.420
.350
.585
.090
.035
.050
.325
.205
.080
.585
RECOMMENDED SOLDER PAD LAYOUT
FOR THICKER SOLDER PASTE APPLICATIONS
RECOMMENDED SOLDER PAD LAYOUT
.090
.035.050
.420
.276
.320
NOTE:
1. DIMENSIONS IN INCH/(MILLIMETER)
2. DRAWING NOT TO SCALE
.300
(7.620)
.075
(1.905)
.183
(4.648)
.060
(1.524)
.060
(1.524)
.256
(6.502)
BOTTOM VIEW OF DD PAK
HATCHED AREA IS SOLDER PLATED
COPPER HEAT SINK
R Package
7-Lead Plastic DD Pak
(Reference LTC DWG # 05-08-1462 Rev F)
DETAIL A
DETAIL A
0° – 7° TYP0° – 7° TYP
LT1210
17
1210fb
For more information www.linear.com/LT1210
package DescripTion
Please refer to http://www.linear.com/product/LT1210#packaging for the most recent package drawings.
.016 – .050
(0.406 – 1.270)
.010 – .020
(0.254 – 0.508)× 45°
0° – 8° TYP
.008 – .010
(0.203 – 0.254)
1
N
2345678
N/2
.150 – .157
(3.810 – 3.988)
NOTE 3
16 15 14 13
.386 – .394
(9.804 – 10.008)
NOTE 3
.228 – .244
(5.791 – 6.197)
12 11 10 9
S16 REV G 0212
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
.245
MIN
N
1 2 3 N/2
.160 ±.005
RECOMMENDED SOLDER PAD LAYOUT
.045 ±.005
.050 BSC
.030 ±.005
TYP
INCHES
(MILLIMETERS)
NOTE:
1. DIMENSIONS IN
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE
S Package
16-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610 Rev G)
LT1210
18
1210fb
For more information www.linear.com/LT1210
package DescripTion
Please refer to http://www.linear.com/product/LT1210#packaging for the most recent package drawings.
.050
(1.27)
.026 – .036
(0.660 – 0.914)
T7 (TO-220) 0801
.135 – .165
(3.429 – 4.191)
.700 – .728
(17.780 – 18.491)
.045 – .055
(1.143 – 1.397)
.165 – .180
(4.191 – 4.572)
.095 – .115
(2.413 – 2.921)
.013 – .023
(0.330 – 0.584)
.620
(15.75)
TYP
.155 – .195*
(3.937 – 4.953)
.152 – .202
(3.860 – 5.130)
.260 – .320
(6.604 – 8.128)
.147 – .155
(3.734 – 3.937)
DIA
.390 – .415
(9.906 – 10.541)
.330 – .370
(8.382 – 9.398)
.460 – .500
(11.684 – 12.700)
.570 – .620
(14.478 – 15.748)
.230 – .270
(5.842 – 6.858)
BSC
SEATING PLANE
*MEASURED AT THE SEATING PLANE
T7 Package
7-Lead Plastic TO-220 (Standard)
(Reference LTC DWG # 05-08-1422)
LT1210
19
1210fb
For more information www.linear.com/LT1210
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision hisTory
REV DATE DESCRIPTION PAGE NUMBER
B 11/15 Added LT1210IR#PBF 1 to 3, 20
(Revision history begins at Rev B)
LT1210
20
1210fb
For more information www.linear.com/LT1210
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
LINEAR TECHNOLOGY CORPORATION 1996
LT 1115 REV B • PRINTED IN USA
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LT1210
relaTeD parTs
Typical applicaTion
PART NUMBER DESCRIPTION COMMENTS
LT1010 Fast ±150mA Power Buffer 20MHz Bandwidth, 75V/µs Slew Rate
LT1166 Power Output Stage Automatic Bias System Sets Class AB Bias Currents for High Voltage/High Power
Output Stages
LT1206 Single 250mA, 60MHz Current Feedback Amplifier Shutdown Function, Stable with CL = 10,000pF, 900V/µs
Slew Rate
LT1207 Dual 250mA, 60MHz Current Feedback Amplifier Dual Version of LT1206
LT1227 Single 140MHz Current Feedback Amplifier Shutdown Function, 1100V/µs Slew Rate
LT1360 Single 50MHz, 800V/µs Op Amp Voltage Feedback, Stable with CL = 10,000pF
LT1363 Single 70MHz, 1000V/µs Op Amp Voltage Feedback, Stable with CL = 10,000pF
LTC6090/LTC6090-5 140V Operational Amplifier 50pA IB, 1.6mV VOS, 9.5V to 140V VS, 4.5µA IS RR Output
LTC6091 140V Operational Amplifier 50pA IB, 1.6mV VOS, 9.5V to 140V VS, 4.5µA IS RR Output
Wideband 9W Bridge Amplifier
Frequency Response
–
+
LT1210
SD 10nF
1
1
1
1
1
T1*
1
RL
50Ω
9W
PO
9W
680Ω
220Ω
100nF
910Ω
* COILTRONICS Versa-Pac™ CTX-01-13033-X2
OR EQUIVALENT
–15V
–15V
15V
15V
INPUT
5VP-P
1210 TA07
–
+
LT1210
SD 10nF FREQUENCY (Hz)
GAIN (dB)
26
23
20
17
14
11
8
5
2
–1
–410k 1M 10M 100M
1210 TA08
100k
