Datasheet

7
LT1169
CCHARA TERIST
ICS
UW
AT
Y
P
I
CA
LPER
F
O
R
C
E
CCIF IMD Test (Equal Amplitude
Tones at 13kHz, 14kHz)*
OUTPUT SWING (V
P-P
)
0.02
0.0001
INTERMODULATION DISTORTION (AT 1kHz)(%)
0.01
1
0.1 1 10 30
LT1169 • TPC26
0.001
0.1
A
V
= ±10
T
A
= 25°C 
V
S
= ±15V
R
L
= 2k
THD and Noise vs Output
Amplitude for Noninverting Gain
OUTPUT SWING (V
P-P
)
0.3
0.0001
TOTAL HARMONIC DISTORTION + NOISE (%)
0.01
1
11030
LT1169 • TPC25
0.001
0.1
Z
L
= 2k 15pF
f
O
= 1kHz
A
V
= 1, 10, 100
MEASUREMENT BANDWIDTH
= 10Hz TO 22kHz
NOISE FLOOR
A
V
= 100
A
V
= 1
A
V
= 10
THD and Noise vs Output
Amplitude for Inverting Gain
OUTPUT SWING (V
P-P
)
0.3
0.0001
TOTAL HARMONIC DISTORTION + NOISE (%)
0.01
1
11030
LT1169 • TPC24
0.001
0.1
Z
L
= 2k 15pF
f
O
= 1kHz
A
V
= –1, –10, –100
MEASUREMENT BANDWIDTH
= 10Hz TO 22kHz
NOISE FLOOR
A
V
= –100
A
V
= –1
A
V
= –10
FREQUENCY (Hz)
20
0.0001
TOTAL HARMONIC DISTORTION + NOISE (%)
0.01
1
100 1k 10k 20k
LT1169 • TPC23
0.001
0.1
Z
L
= 2k 15pF
V
O
= 20V
P-P

A
V
= –1, –10, –100
MEASUREMENT BANDWIDTH
= 10Hz TO 80kHz
NOISE FLOOR
A
V
= –100
A
V
= –1
A
V
= –10
THD and Noise vs
Frequency for Inverting Gain
FREQUENCY (Hz)
20
0.0001
TOTAL HARMONIC DISTORTION + NOISE (%)
0.01
1
100 1k 10k 20k
LT1169 • TPC22
0.001
0.1
Z
L
= 2k 15pF
V
O
= 20V
P-P

A
V
= 1, 10, 100
MEASUREMENT BANDWIDTH
= 10Hz TO 80kHz
NOISE FLOOR
A
V
= 100
A
V
= 10
A
V
= 1
THD and Noise vs
Frequency for Noninverting Gain
*SEE LT1115 DATA SHEET FOR DEFINITION OF
CCIF TESTING
U
S
A
O
PP
L
IC
AT
I
WU
U
I FOR ATIO
LT1169 vs the Competition
With improved noise performance, the LT1169 dual in the
plastic DIP directly replaces such JFET op amps as the
OPA2111, OPA2604, OP215, and the AD822. The combi-
nation of low current and voltage noise of the LT1169
allows it to surpass most dual and single JFET op amps.
The LT1169 can replace many of the lowest noise bipolar
amps that are used in amplifying low level signals from
high impedance transducers. The best bipolar op amps
will eventually lose out to the LT1169 when transducer
impedance increases due to higher current noise.
The extremely high input impedance (10
13
Ω) assures that
the input bias current is almost constant over the entire
common mode range. Figure 1 shows how the LT1169
stands up to the competition. Unlike the competition, as the
input voltage is swept across the entire common mode
range the input bias current of the LT1169 hardly changes.
As a result the current noise does not degrade. This makes
the LT1169 the best choice in applications where an
amplifier has to buffer signals from a high impedance
transducer.