1
LT1225
Very High Speed
Operational Amplifier
s
Gain of 5 Stable
s
150MHz Gain Bandwidth
s
400V/
s Slew Rate
s
20V/mV DC Gain, R
L
= 500
s
1mV Maximum Input Offset Voltage
s
12V Minimum Output Swing into 500
s
Wide Supply Range:
2.5V to
15V
s
7mA Supply Current
s
90ns Settling Time to 0.1%, 10V Step
s
Drives All Capacitive Loads
D
U
ESCRIPTIO
S
FEATURE
The LT1225 is a very high speed operational amplifier with
excellent DC performance. The LT1225 features reduced
input offset voltage and higher DC gain than devices with
comparable bandwidth and slew rate. The circuit is a
single gain stage with outstanding settling characteristics.
The fast settling time makes the circuit an ideal choice for
data acquisition systems. The output is capable of driving
a 500
load to
12V with
15V supplies and a 150
load
to
3V on
5V supplies. The circuit is also capable of
driving large capacitive loads which makes it useful in
buffer or cable driver applications.
The LT1225 is a member of a family of fast, high per-
formance amplifiers that employ Linear Technology
Corporation's advanced bipolar complementary
processing.
U
S
A
O
PPLICATI
s
Wideband Amplifiers
s
Buffers
s
Active Filters
s
Video and RF Amplification
s
Cable Drivers
s
Data Acquisition Systems
U
A
O
PPLICATI
TYPICAL
20MHz,A
V
= 50 Instrumentation Amplifier
Gain of 5 Pulse Response
+
+
+
LT1225
LT1225
LT1225
1k
V
IN
1k
V
OUT
200pF
250
250
1k
1k
10k
10k
+
LT1225 TA01
LT1225 TA02
LT1225
2
Total Supply Voltage (V
+
to V
) .............................. 36V
Differential Input Voltage .........................................
6V
Input Voltage ............................................................
V
S
Output Short Circuit Duration (Note 1) ............ Indefinite
Operating Temperature Range
LT1225C ................................................ 0
C to 70
C
Maximum Junction Temperature
Plastic Package .............................................. 150
C
Storage Temperature Range ................. 65
C to 150
C
Lead Temperature (Soldering, 10 sec.)................. 300
C
A
U
G
W
A
W
U
W
A
R
BSOLUTE
XI
TI
S
W
U
U
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage
(Note 2)
0.5
1.0
mV
I
OS
Input Offset Current
100
400
nA
I
B
Input Bias Current
4
8
A
e
n
Input Noise Voltage
f = 10kHz
7.5
nV/
Hz
i
n
Input Noise Current
f = 10kHz
1.5
pA/
Hz
R
IN
Input Resistance
V
CM
=
12V
24
40
M
Differential
70
k
C
IN
Input Capacitance
2
pF
Input Voltage Range +
12
14
V
Input Voltage Range
13
12
V
CMRR
Common-Mode Rejection Ratio
V
CM
=
12V
94
115
dB
PSRR
Power Supply Rejection Ratio
V
S
=
5V to
15V
86
95
dB
A
VOL
Large Signal Voltage Gain
V
OUT
=
10V, R
L
= 500
12.5
20
V/mV
V
OUT
Output Swing
R
L
= 500
12.0
13.3
V
I
OUT
Output Current
V
OUT
=
12V
24
40
mA
SR
Slew Rate
(Note 3)
250
400
V/
s
Full Power Bandwidth
10V Peak, (Note 4)
6.4
MHz
GBW
Gain Bandwidth
f = 1MHz
150
MHz
t
r
, t
f
Rise Time, Fall Time
A
VCL
= 5, 10% to 90%, 0.1V
7
ns
Overshoot
A
VCL
= 5, 0.1V
20
%
Propagation Delay
50% V
IN
to 50% V
OUT
7
ns
t
s
Settling Time
10V Step, 0.1%, A
V
= 5
90
ns
Differential Gain
f = 3.58MHz, A
V
= 5, R
L
= 150
1.0
%
Differential Phase
f = 3.58MHz, A
V
= 5, R
L
= 150
1.7
Deg
R
O
Output Resistance
A
VCL
= 5, f = 1MHz
4.5
I
S
Supply Current
7
9
mA
ELECTRICAL C
C
HARA TERISTICS
V
S
=
15V, T
A
= 25
C, V
CM
= 0V unless otherwise noted.
S8 PART MARKING
1225
LT1225CN8
LT1225CS8
1
2
3
4
5
6
7
8
TOP VIEW
NULL
V
+
NULL
IN
OUT
NC
+IN
V
S8 PACKAGE
8-LEAD PLASTIC SOIC
N8 PACKAGE
8-LEAD PLASTIC DIP
LT1225 PO01
T
J MAX
= 15O
C,
JA
= 130
C/ W (N8)
T
J MAX
= 15O
C,
JA
= 220
C/ W (S8)
3
LT1225
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage
V
S
=
15V, (Note 2)
0.5
1.5
mV
V
S
=
5V, (Note 2)
1.0
2.5
mV
Input V
OS
Drift
10
V/
C
I
OS
Input Offset Current
V
S
=
15V and V
S
=
5V
100
600
nA
I
B
Input Bias Current
V
S
=
15V and V
S
=
5V
4
9
A
CMRR
Common-Mode Rejection Ratio
V
S
=
15V, V
CM
=
12V and V
S
=
5V, V
CM
=
2.5V
93
115
dB
PSRR
Power Supply Rejection Ratio
V
S
=
5V to
15V
85
95
dB
A
VOL
Large Signal Voltage Gain
V
S
=
15V, V
OUT
=
10V, R
L
= 500
10
12.5
V/mV
V
S
=
5V, V
OUT
=
2.5V, R
L
= 500
8
10
V/mV
V
OUT
Output Swing
V
S
=
15V, R
L
= 500
12.0
13.3
V
V
S
=
5V, R
L
= 500
or 150
3.0
3.3
V
I
OUT
Output Current
V
S
=
15V, V
OUT
=
12V
24
40
mA
V
S
=
5V, V
OUT
=
3V
20
40
mA
SR
Slew Rate
V
S
=
15V, (Note 3)
250
400
V/
s
I
S
Supply Current
V
S
=
15V and V
S
=
5V
7
10.5
mA
V
S
=
5V, T
A
= 25
C, V
CM
= 0V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
OS
Input Offset Voltage
(Note 2)
1.0
2.0
mV
I
OS
Input Offset Current
100
400
nA
I
B
Input Bias Current
4
8
A
Input Voltage Range +
2.5
4
V
Input Voltage Range
3
2.5
V
CMRR
Common-Mode Rejection Ratio
V
CM
=
2.5V
94
115
dB
A
VOL
Large-Signal Voltage Gain
V
OUT
=
2.5V, R
L
= 500
10
15
V/mV
V
OUT
=
2.5V, R
L
= 150
13
V/mV
V
OUT
Output Voltage
R
L
= 500
3.0
3.7
V
R
L
= 150
3.0
3.3
V
I
OUT
Output Current
V
OUT
=
3V
20
40
mA
SR
Slew Rate
(Note 3)
250
V/
s
Full Power Bandwidth
3V Peak, (Note 4)
13.3
MHz
GBW
Gain Bandwidth
f = 1MHz
100
MHz
t
r
, t
f
Rise Time, Fall Time
A
VCL
= 5, 10% to 90%, 0.1V
9
ns
Overshoot
A
VCL
= 5, 0.1V
10
%
Propagation Delay
50% V
IN
to 50% V
OUT
9
ns
t
s
Settling Time
2.5V to 2.5V, 0.1%, A
V
= 4
70
ns
I
S
Supply Current
7
9
mA
ELECTRICAL C
C
HARA TERISTICS
ELECTRICAL C
C
HARA TERISTICS
Note 3: Slew rate is measured between
10V on an output swing of
12V
on
15V supplies, and
2V on an output swing of
3.5V on
5V supplies.
Note 4: Full power bandwidth is calculated from the slew rate
measurement: FPBW = SR/2
Vp.
Note 1: A heat sink may be required to keep the junction temperature
below absolute maximum when the output is shorted indefinitely.
Note 2: Input offset voltage is tested with automated test equipment
in <1 second.
0
C
T
A
70
C, V
CM
= 0V unless otherwise noted.
LT1225
4
C
C
HARA TERISTICS
U
W
A
TYPICAL PERFOR
CE
Output Short-Circuit Current vs
Supply Current vs Temperature
Input Bias Current vs Temperature
Temperature
Output Voltage Swing vs
Input Bias Current vs Input
Open-Loop Gain vs
Resistive Load
Common-Mode Voltage
Resistive Load
Input Common-Mode Range vs
Output Voltage Swing vs
Supply Voltage
Supply Current vs Supply Voltage
Supply Voltage
SUPPLY VOLTAGE (V)
0
0
MAGNITUDE OF INPUT VOLTAGE (V)
5
10
15
20
5
10
15
20
LT1225 TPC01
T
A
= 25C
V
OS
< 1mV
+V
CM
V
CM
SUPPLY VOLTAGE (V)
0
6.0
SUPPLY CURRENT (mA) 6.5
7.0
7.5
8.0
5
10
15
20
LT1225 TPC02
T
A
= 25C
SUPPLY VOLTAGE (V)
0
0
OUTPUT VOLTAGE SWING (V)
5
10
15
20
5
10
15
20
LT1225 TPC03
T
A
= 25C
R
L
= 500
V
OS
= 30mV
+V
SW
V
SW
LOAD RESISTANCE (
)
10
0
OUTPUT VOLTAGE SWING (Vp-p)
10
20
25
30
100
1k
10k
LT1225 TPC04
15
5
T
A
= 25C
V
OS
= 30mV
V
S
= 15V
V
S
= 5V
INPUT COMMON-MODE VOLTAGE (V)
15
3.0
INPUT BIAS CURRENT (
A)
3.5
4.0
4.5
5.0
10
0
10
15
LT1225 TPC05
5
5
V
S
= 15V
T
A
= 25C
I
B+
+ I
B
2
I
B
=
LOAD RESISTANCE (
)
10
50
OPEN-LOOP GAIN (dB)
80
90
100
100
1k
10k
LT1225 TPC06
70
60
T
A
= 25C
V
S
= 15V
V
S
= 5V
TEMPERATURE (C)
50
25
OUTPUT SHORT-CIRCUIT CURRENT (mA)
35
40
50
55
25
25
75
125
LT1225 TPC09
100
50
0
30
45
V
S
= 5V
SINK
SOURCE
TEMPERATURE (C)
50
3.5
INPUT BIAS CURRENT (
A)
4.0
4.25
4.75
5.0
25
25
75
125
LT1225 TPC08
100
50
0
3.75
4.5
V
S
= 15V
I
B+
+ I
B
2
I
B
=
TEMPERATURE (C)
50
4
SUPPLY CURRENT (mA)
6
7
9
10
25
25
75
125
LT1225 TPC07
V
S
= 15V
100
50
0
5
8
5
LT1225
C
C
HARA TERISTICS
U
W
A
TYPICAL PERFOR
CE
Closed-Loop Output Impedance vs
Frequency
Gain Bandwidth vs Temperature
Slew Rate vs Temperature
Power Supply Rejection Ratio vs
Common-Mode Rejection Ratio vs
Input Noise Spectral Density
Frequency
Frequency
TEMPERATURE (C)
50
GAIN BANDWIDTH (MHz)
151
152
153
25
75
LT1225 TPC17
150
149
25
0
50
100
125
148
147
V
S
= 15V
TEMPERATURE (C)
50
SLEW RATE (V/
s)
400
450
500
25
75
LT1225 TPC18
350
300
25
0
50
100
125
250
200
SR
+SR
V
S
= 15V
A
V
= 5
FREQUENCY (Hz)
INPUT VOLTAGE NOISE (nV/
Hz)
1
100
10
1k
10k
100k
LT1225 TPC10
100
1000
10
V
S
= 15V
T
A
= 25C
A
V
= 101
R
S
= 100k
i
n
e
n
0.01
1.0
10
0.1
INPUT CURRENT NOISE (pA/
Hz)
FREQUENCY (Hz)
1k
0
COMMON MODE REJECTION RATIO (dB)
20
40
60
80
100
120
10k
100k
1M
10M
LTXXXX TPCXX
100M
V
S
= 15V
T
A
= 25C
FREQUENCY (Hz)
100
0
POWER SUPPLY REJECTION RATIO (dB)
20
40
60
80
100
1k
10k
100k
1M
LT1225 TPC11
10M
100M
V
S
= 15V
T
A
= 25C
+PSRR
PSRR
Voltage Gain and Phase vs
Frequency Response vs
Frequency
Output Swing vs Settling Time
Capacitive Load
SETTLING TIME (ns)
0
OUTPUT SWING (V)
2
6
10
80
2
6
10
20
40
60
100
120
LTC1225 TPC14
0
4
8
4
8
V
S
= 15
T
A
= 25C
10mV SETTLING
A
V
= 5
A
V
= 5
A
V
= 5
A
V
= 5
FREQUENCY (HZ)
1M
4
VOLTAGE MAGNITUDE (dB)
8
12
16
20
24
10M
100M
V
S
= 15V
T
A
= 25C
A
V
= 5
C = 100pF
C = 0pF
C = 50pF
LT1225 TPC15
6
10
14
18
22
C = 1000pF
C = 500pF
FREQUENCY (Hz)
10k
OUTPUT IMPEDANCE (
)
1
10
100M
LT1225 TPC16
0.1
0.01
100k
1M
10M
100
V
S
= 15V
T
A
= 25C
A
V
= 5
FREQUENCY (Hz)
100
0
VOLTAGE GAIN (dB)
20
40
60
80
100
1k
10k
100k
1M
LT1225 TPC13
10M
100M
0
20
40
60
80
100
PHASE MARGIN (DEG)
V
S
= 15V
V
S
= 5V
T
A
= 25C
V
S
= 5V
V
S
= 15V
PDF 
ZIP