LT1969
Dual 700MHz, 200mA,
Adjustable Current Operational Amplifier
FEATURES
s
s
s
s
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
700MHz Gain Bandwidth
±200mA
Minimum I
OUT
Adjustable Quiescent Current
Low Distortion: –72dBc at 1MHz, 4V
P-P
, 25Ω, A
V
= 2
Stable in A
V
≥
10, Simple Compensation for A
V
< 10
±4.3V
Minimum Output Swing, V
S
=
±6V,
R
L
= 25Ω
Stable with 1000pF Load
6nV/√Hz Input Noise Voltage
2pA/√Hz Input Noise Current
4mV Maximum Input Offset Voltage
4µA Maximum Input Bias Current
400nA Maximum Input Offset Current
±4.5V
Minimum Input CMR, V
S
=
±6V
Specified at
±6V, ±2.5V
The LT
®
1969 is an adjustable current version of the
popular LT1886, a 200mA minimum output current, dual
op amp with outstanding distortion performance. The
adjustable current feature is highly desirable in applica-
tions where minimum power dissipation is required while
still being able to provide adequate line termination.
At nominal supply current, the amplifiers are gain of 10
stable and can easily be compensated for lower gains. The
LT1969 features balanced high impedance inputs with
4µA input bias current and 4mV maximum input offset
voltage. Single supply applications are easy to implement
and have lower total noise than current feedback amplifier
implementations.
The output drives a 25Ω load to
±4.3V
with
±6V
supplies.
On
±2.5V
supplies, the output swings
±1.5V
with a 100Ω
load. The amplifier is stable with a 1000pF capacitive load
making it useful in buffer and cable driver applications.
The LT1969 is manufactured on Linear Technology’s
advanced low voltage complementary bipolar process and
is available in a thermally enhanced MS10 package
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
DSL Modems
xDSL PCI Cards
USB Modems
Line Drivers
TYPICAL APPLICATIO
12V
0.1µF
IN
+
Single 12V Supply ADSL Modem Line Driver
ADSL Modem Line Driver Distortion
–60
12.4Ω
HARMONIC DISTORTION (dBc)
+
1/2 LT1969
–
909Ω
10k
20k
100Ω
1:2*
*COILCRAFT X8390-A
OR EQUIVALENT
100Ω
1µF
10k
20k
1µF
100Ω
909Ω
CTRL1 CTRL2
I
Q
ON = 14mA
I
Q
LOW POWER = 2mA
I
Q
STANDBY = 600µA
STANDBY ON
LOGIC
OUTPUT
STANDBY
LOW POWER ON
1969 TA01a
6
12.4Ω
13k
7
49.9k
0.1µF
IN
–
1/2 LT1969
U
–70
V
S
= 12V
A
V
= 10
f = 200kHz
100Ω LINE
1:2 TRANSFORMER
HD2
–80
–90
HD3
–100
0
2
4
6
8
10 12
LINE VOLTAGE (V
P-P
)
14
16
1969 TA01b
U
+
–
U
1
LT1969
ABSOLUTE
MAXIMUM
RATINGS
(Note 1)
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
V
+
OUTA
–INA
+INA
V
–
1
2
3
4
5
10
9
8
7
6
OUTB
–INB
+INB
CTRL2
CTRL1
Total Supply Voltage (V
+
to V
–
) ........................... 13.2V
Input Current (Note 2) .......................................
±10mA
Input Voltage (Note 2) ............................................
±V
S
Maximum Continuous Output Current (Note 3)
DC ...............................................................
±100mA
AC ...............................................................
±300mA
Operating Temperature Range (Note 10) – 40°C to 85°C
Specified Temperature Range (Note 9) .. – 40°C to 85°C
Maximum Junction Temperature ......................... 150°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
LT1969CMS
MS10 PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 110°C/W (NOTE 4)
MS10 PART MARKING
LTTN
Consult factory for parts specified with wider operating temperature ranges.
The
q
denotes specifications which apply over the full operating temp-
erature range, otherwise specifications are at T
A
= 25°C. V
S
=
±6V,
V
CM
= 0V, nominal mode with a 13k resistor from CTRL1 to V
–
and
a 49.9k resistor from CTRL2 to V
–
, pulse power tested unless otherwise noted. (Note 9)
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
Input Offset Voltage Drift
I
OS
I
B
e
n
i
n
R
IN
C
IN
Input Offset Current
q
ELECTRICAL CHARACTERISTICS
(Note 5)
CONDITIONS
q
MIN
TYP
1
MAX
4
5
17
400
600
4
6
UNITS
mV
mV
µV/°C
nA
nA
µA
µA
nV/√Hz
pA/√Hz
MΩ
kΩ
pF
V
V
dB
V
dB
dB
V/mV
V/mV
V/mV
V/mV
±V
±V
±V
±V
±V
±V
(Note 8)
q
3
150
1.5
Input Bias Current
q
Input Noise Voltage
Input Noise Current
Input Resistance
Input Capacitance
Input Voltage Range (Positive)
Input Voltage Range (Negative)
f = 10kHz
f = 10kHz
V
CM
=
±4.5V
Differential
q
q
6
2
5
10
35
2
4.5
77
80
78
5.0
4.5
4.5
4.0
4.85
4.70
4.30
4.10
4.30
4.10
5.9
– 5.2
98
±2
86
12
12
5
4.6
4.5
– 4.5
CMRR
PSRR
A
VOL
Common Mode Rejection Ratio
Minimum Supply Voltage
Power Supply Rejection Ratio
Large-Signal Voltage Gain
V
CM
=
±4.5V
Guaranteed by PSRR
V
S
=
±2V
to
±6.5V
q
q
q
V
OUT
=
±4V,
R
L
= 100Ω
q
V
OUT
=
±4V,
R
L
= 25Ω
q
V
OUT
Output Swing
R
L
= 100Ω, 10mV Overdrive
q
R
L
= 25Ω, 10mV Overdrive
q
I
OUT
= 200mA, 10mV Overdrive
q
2
U
W
U
U
W W
W
LT1969
The
q
denotes specifications which apply over the full operating temp-
erature range, otherwise specifications are at T
A
= 25°C. V
S
=
±6V,
V
CM
= 0V, nominal mode with a 13k resistor from CTRL1 to V
–
and
a 49.9k resistor from CTRL2 to V
–
, pulse power tested unless otherwise noted. (Note 9)
SYMBOL
I
SC
SR
GBW
t
r
, t
f
PARAMETER
Short-Circuit Current (Sourcing)
Short-Circuit Current (Sinking)
Slew Rate
Full Power Bandwidth
Gain Bandwidth
Rise Time, Fall Time
Overshoot
Propagation Delay
t
S
Settling Time
Harmonic Distortion
IMD
R
OUT
I
S
Intermodulation Distortion
Output Resistance
Supply Current
CTRL1 Voltage
CTRL2 Voltage
Minimum Supply Current
Maximum Supply Current
CONDITIONS
(Note 3)
A
V
= –10 (Note 6)
4V Peak (Note 7)
f = 1MHz
A
V
= 10, 10% to 90% of 0.1V, R
L
= 100Ω
A
V
= 10, 0.1V, R
L
= 100Ω
A
V
= 10, 50% V
IN
to 50% V
OUT
, 0.1V, R
L
= 100Ω
6V Step, 0.1%
HD2, A
V
= 10, 2V
P-P
, f = 1MHz, R
L
= 100Ω/25Ω
HD3, A
V
= 10, 2V
P-P
, f = 1MHz, R
L
= 100Ω/25Ω
A
V
= 10, f = 0.9MHz, 1MHz, 14dBm, R
L
= 100Ω/25Ω
A
V
= 10, f = 1MHz
Per Amplifier
q
ELECTRICAL CHARACTERISTICS
MIN
TYP
700
500
MAX
UNITS
mA
mA
V/µs
MHz
MHz
ns
%
ns
ns
dBc
dBc
dBc
Ω
100
200
8
700
4
1
2.5
50
–75/–63
–85/–71
–81/–80
0.1
7
8.25
8.50
1.25
1.30
1.18
1.25
800
1100
mA
mA
V
V
V
V
µA
µA
mA
13k to V
–
, Measured with Respect to V
–
q
0.77
0.74
0.87
0.80
0.97
1.05
300
49.9k to V
–
, Measured with Respect to V
–
q
per Amplifier; CTRL1, CTRL2 Open
q
per Amplifier; CTRL1 or CTRL2 Shorted to V
–
13
The
q
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
S
=
±2.5V,
V
CM
= 0V, nominal mode with a 13k resistor from CTRL1 to V
–
and a 49.9k resistor from CTRL2 to V
–
, pulse power tested
unless otherwise noted. (Note 9)
SYMBOL
V
OS
PARAMETER
Input Offset Voltage
Input Offset Voltage Drift
I
OS
I
B
e
n
i
n
R
IN
C
IN
Input Offset Current
q
CONDITIONS
(Note 5)
q
MIN
TYP
1.5
MAX
5
6
17
350
550
3.5
5.5
UNITS
mV
mV
µV/°C
nA
nA
µA
µA
nV/√Hz
pA/√Hz
MΩ
kΩ
pF
V
V
dB
(Note 8)
q
5
100
1.2
Input Bias Current
q
Input Noise Voltage
Input Noise Current
Input Resistance
Input Capacitance
Input Voltage Range (Positive)
Input Voltage Range (Negative)
f = 10kHz
f = 10kHz
V
CM
=
±1V
Differential
q
q
6
2
10
20
50
2
1
75
2.4
–1.7
91
–1
CMRR
Common Mode Rejection Ratio
V
CM
=
±1V
q
3
LT1969
The
q
denotes specifications which apply over the full operating temp-
erature range, otherwise specifications are at T
A
= 25°C. V
S
=
±2.5V,
V
CM
= 0V, nominal mode with a 13k resistor from CTRL1 to V
–
and a 49.9k resistor from CTRL2 to V
–
, pulse power tested unless otherwise noted. (Note 9)
SYMBOL
A
VOL
PARAMETER
Large-Signal Voltage Gain
CONDITIONS
V
OUT
=
±1V,
R
L
= 100Ω
q
ELECTRICAL CHARACTERISTICS
MIN
5.0
4.5
4.5
4.0
1.50
1.40
1.35
1.25
0.87
0.80
TYP
10
10
1.65
1.50
1
500
400
MAX
UNITS
V/mV
V/mV
V/mV
V/mV
±V
±V
±V
±V
±V
±V
mA
mA
V/µs
MHz
MHz
ns
%
ns
dBc
dBc
dBc
Ω
dB
dB
V
OUT
=
±1V,
R
L
= 25Ω
q
V
OUT
Output Swing
R
L
= 100Ω, 10mV Overdrive
q
R
L
= 25Ω, 10mV Overdrive
q
I
OUT
= 200mA, 10mV Overdrive
q
I
SC
SR
GBW
t
r
, t
f
Short-Circuit Current (Sourcing)
Short-Circuit Current (Sinking)
Slew Rate
Full Power Bandwidth
Gain Bandwidth
Rise Time, Fall Time
Overshoot
Propagation Delay
Harmonic Distortion
(Note 3)
A
V
= –10 (Note 6)
1V Peak (Note 7)
f = 1MHz
A
V
= 10, 10% to 90% of 0.1V, R
L
= 100Ω
A
V
= 10, 0.1V, R
L
= 100Ω
A
V
= 10, 50% V
IN
to 50% V
OUT
, 0.1V, R
L
= 100Ω
HD2, A
V
= 10, 2V
P-P
, f = 1MHz, R
L
= 100Ω/25Ω
HD3, A
V
= 10, 2V
P-P
, f = 1MHz, R
L
= 100Ω/25Ω
A
V
= 10, f = 0.9MHz, 1MHz, 5dBm, R
L
= 100Ω/25Ω
A
V
= 10, f = 1MHz
V
OUT
=
±1V,
R
L
= 25Ω
q
50
100
16
530
7
5
5
–75/– 64
– 80/– 66
– 77/– 85
0.2
IMD
R
OUT
Intermodulation Distortion
Output Resistance
Channel Separation
82
80
92
5
6.00
6.25
1.25
1.30
1.18
1.25
650
750
I
S
Supply Current
CTRL1 Voltage
CTRL2 Voltage
Minimum Supply Current
Maximum Supply Current
Per Amplifier
q
mA
mA
V
V
V
V
µA
µA
mA
13k to V
–
, Measured with Respect to V
–
q
0.77
0.74
0.87
0.80
0.95
1.03
250
49.9k to V
–
, Measured with Respect to V
–
q
per Amplifier; CTRL1, CTRL2 Open
q
per Amplifier; CTRL1 or CTRL2 Shorted to V
–
11.5
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
The inputs are protected by back-to-back diodes. If the differential
input voltage exceeds 0.7V, the input current should be limited to less than
10mA.
Note 3:
A heat sink may be required to keep the junction temperature
below absolute maximum.
Note 4:
Thermal resistance varies depending upon the amount of PC board
metal attached to the device.
θ
JA
is specified for a 2500mm
2
test board
covered with 2 oz copper on both sides.
Note 5:
Input offset voltage is exclusive of warm-up drift.
Note 6:
Slew rate is measured between
±2V
on a
±4V
output with
±6V
supplies, and between
±1V
on a
±1.5V
output with
±2.5V
supplies. Falling
slew rate is guaranteed by correlation to rising slew rate.
Note 7:
Full power bandwidth is calculated from the slew rate:
FPBW = SR/2πV
P
.
Note 8:
This parameter is not 100% tested.
Note 9:
The LT1969C is guaranteed to meet specified performance from 0°C
to 70°C. The LT1969C is designed, characterized and expected to meet
specified performance from –40°C to 85°C but is not tested or QA sampled
at these temperatures.
Note 10:
The LT1969C is guaranteed functional over the operating temperature
range of –40°C to 85°C.
4
LT1969
TYPICAL PERFOR A CE CHARACTERISTICS
–
–
13k resistor from CTRL1 to V and a 49.9k resistor from CTRL2 to V
Supply Current vs Temperature
SUPPLY CURRENT, BOTH AMPLIFIERS (mA)
20
18
–0.1
COMMON MODE RANGE (V)
14
12
10
8
6
4
2
0
–50 –25
V
S
=
±6V
V
S
=
±2.5V
–0.2
–0.3
1.5
1.0
0.5
V
–
0
T
A
= 25°C
∆V
OS
> 1mV
2
4
6
8
10
12
TOTAL SUPPLY VOLTAGE (V)
14
INPUT BIAS CURRENT (µA)
16
50
25
0
75
TEMPERATURE (°C)
Input Bias Current
vs Temperature
3.5
3.0
INPUT BIAS CURRENT (µA)
I
B
= (I
B+
– I
B–
)/2
INPUT VOLTAGE NOISE (nV/√Hz)
OUTPUT SATURATION VOLTAGE (V)
2.5
2.0
1.5
V
S
=
±6V
1.0
0.5
0
–50 –25
V
S
=
±2.5V
50
25
75
0
TEMPERATURE (°C)
Output Saturation Voltage
vs Temperature
V
OUTPUT SATURATION VOLTAGE (V)
+
OUTPUT SHORT-CIRCUIT CURRENT (mA)
V
S
=
±2.5V
R
L
= 100Ω
150mA
200mA
–0.5
–1.0
–1.5
1.5
1.0
150mA
0.5
V
–
–50 –25
OUTPUT STEP (V)
200mA
R
L
= 100Ω
50
25
75
0
TEMPERATURE (°C)
U W
100
1969 G01
Input Common Mode Range
vs Supply Voltage
V
+
Input Bias Current
vs Input Common Mode Voltage
3.0
2.5
2.0
V
S
=
±6V
1.5
1.0
0.5
0
–6
–4
–2
0
2
4
INPUT COMMON MODE VOLTAGE (V)
6
V
S
=
±2.5V
T
A
= 25°C
I
B
= (I
B +
+ I
B –
)/2
125
1969 G02
1969 G03
Input Noise Spectral Density
100
T
A
= 25°C
A
V
= 101
100
INPUT CURRENT NOISE (pA/√Hz)
V
+
–0.5
Output Saturation Voltage
vs Temperature
V
S
=
±6V
R
L
= 100Ω
–1.0
150mA
–1.5
1.5
1.0
150mA
0.5
V
–
–50 –25
R
L
= 100Ω
200mA
200mA
10
e
n
i
n
10
100
125
1
10
100
1k
10k
FREQUENCY (Hz)
1
100k
1969 G04
50
25
75
0
TEMPERATURE (°C)
100
125
1969 G43
1969 G44
Output Short-Circuit Current
vs Temperature
1000
900
800
700
600
500
400
300
200
100
0
–50 –25
50
25
0
75
TEMPERATURE (°C)
100
125
–6
6
Settling Time vs Output Step
V
S
=
±6V
10mV
2
0
–2
–4
10mV
0
10
20
30
40
SETTLING TIME (ns)
1mV
50
60
1886 G05
SOURCE
V
S
=
±6V
SOURCE
V
S
=
±2.5V
4
1mV
SINK
V
S
=
±6V
SINK
V
S
=
±2.5V
100
125
1969 G45
1969 G46
5
微控制器 MCU
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