LT1491_15 Datasheet, PDF (9/12 Pages) Linear Technology – Dual and Quad Micropower Rail-to-Rail Input and Output Op Amps

LT1490/LT1491
APPLICATIO S I FOR ATIO
Gain
The open-loop gain is almost independent of load when
the output is sourcing current. This optimizes perfor-
mance in single supply applications where the load is
returned to ground. The typical performance photo of
Open-Loop Gain for various loads shows the details.
TYPICAL APPLICATIO S
Square Wave Oscillator
5V
100k
100k
59k
+
1/2 LT1490
–
R
50k
C
0.1µF
1490/91 TA02
V_OUT
f
=
1
2RC
V_OUT = 5V_P-P WITH 5V SUPPLY
I_S = 200µA
AT V_S = 5V, R = 50k, C = 1nF
OUTPUT IS 5kHz SLEW LIMITED TRIANGLE WAVE
Optional Output Compensation for
Capacitive Loads Greater Than 200pF
V_IN
+
1/2 LT1490
–
C_L ≤ 10,000pF
0.22µF
150Ω
1490/91 TA04
W
W
SI PLIFIED SCHE ATIC
Q1
R1
30k
Q4
+
2µA
R2
1k
– IN
R3
1k
+ IN
Q2
D1
D2
Q7 Q8
Q11 Q12
Q9
Q10
Q13
Q3
D3
V⁺
Q22
Q15
Q14
Q19
Q17
Q16 Q18
Q20
OUT
Q21
Q5
Q6
ONE AMPLIFIER
D4 D5
R4
R5
40k
40k
V^–
1490/91 SS
9