LT1466 LINER [Linear Technology], LT1466 Datasheet - Page 8

• Manufacturer Part Number: LT1466
• Description: Micropower Dual/Quad Precision Rail-to-Rail Input and Output Op Amps
• Manufacturer: LINER [Linear Technology]

TYPICAL PERFORMANCE CHARACTERISTICS
APPLICATIONS
LT1466L/LT1467L
8
Rail-to-Rail Operation
The LT1466L/LT1467L differ from conventional op amps
in the design of both the input and output stages. Figure 1
shows a simplified schematic. The input stage consists of
two differential amplifiers, a PNP stage Q1-Q2 and an NPN
stage Q3-Q4, that are active over different portions of the
input common mode range. Each input stage is trimmed
for offset voltage. A complementary output configuration
(Q12-Q13) is employed to create an output stage with rail-
to-rail swing. The devices are fabricated on Linear
130
120
110
100
90
80
70
60
50
40
30
100
Channel Separation vs Frequency
1k
FREQUENCY (Hz)
+ IN
– IN
V
V
+
–
U
10k
Q3
INFORMATION
U
V
W
S
Q4
Q6
1466L/67L G24
= 15V
100k
U
W
Q1
Q2
I
1
Figure 1. Simplified Schematic
Q5
Small-Signal Response
V
V
A
U
S
S
V
= 2.5V
= 1
= 2.5V
D1
V
BIAS
Q7
V
+
Q10
Q8
Technology’s proprietary complementary bipolar process,
which ensures very similar DC and AC characteristics for
the output devices Q12 and Q13.
First, looking at the input stage, Q5 switches the current
from current source I
When the input common mode voltage V
negative supply, Q5 is reverse biased, so the current from
I
Q1-Q2. At the other extreme, when V
supply, the PNPs Q1-Q2 are biased off. The current from
1
becomes the tail current for the PNP differential pair
Q11
Q9
1466L/67L G22
C
C
V
OUTPUT BIAS
–
BUFFER AND
1
between the two input stages.
Large-Signal Response
V
V
A
S
S
V
= 5V
= 1
= 5V
C1
C2
Q12
Q13
CM
1466L/67L F01
is near the positive
OUT
CM
is near the
1466L/67L G23