11

LT1366/LT1367

LT1368/LT1369

(The data presented here applies to the LT1366/LT1367/LT1368/ LT1369 unless otherwise noted.)

THD + Noise vs Frequency

Small-Signal Response

(LT1366/LT1367)

2

µs/DIV

UNITY-GAIN

LT1366 TPC30

Large-Signal Response

(LT1366/LT1367)

100

µs/DIV

UNITY-GAIN

LT1366 TPC29

0V

FREQUENCY (kHz)

0.01

0.001

0.01

0.1

1

0.1

1

10

LT1366 TPC28

Rail-to-Rail Operation

The LT1366 family differs from conventional op amps in

the design of both the input and output stages. Figure 1

shows a simplified schematic of the amplifier. The input

stage consists of two differential amplifiers, a PNP stage

Q1/Q2 and an NPN stage Q3/Q4, which are active over

different portions of the input common mode range.

Lateral devices are used in both input stages, eliminating

the need for clamps across the input pins. Each input stage

is trimmed for offset voltage. A complementary output

configuration (Q23 through Q26) is employed to create an

output stage with rail-to-rail swing. The amplifier is fabri-

Q24

D7

Q23

Q25

C1

C2

Q26

D8

Q22

Q21

D6

Q17

Q16

Q18

Q15

Q19

Q20

D5

D4

D7

Q11

I1

Q10

Q14

Q13

Q9

Q8

Q7

D2

Q1 Q2

Q5

D1

Q3 Q4

Q6

D3

Q12

OUT

– 300mV

LT1366 FO1

Figure 1. LT1366 Simplified Schematic Diagram