pole at frequency (2

combination of the gain-setting resistors for the invert-

ing or noninverting amplifier configuration (Figure 2). If

the pole frequency is less than or comparable to the

unity-gain bandwidth (10MHz), the phase margin will

be reduced, and the amplifier will exhibit degraded

AC performance through either ringing in the step

response or sustained oscillations. The pole frequency is

10MHz when R

′ = 3.2kΩ. To maximize stability, R′ <3kΩ

is recommended.

Applications that require rail-to-rail operation with mini-

typically require R

′ values >3kΩ. To improve step

response under these conditions, connect a small

ting resistor (Figure 2).

Figure 3 shows the step response for a noninverting

amplifier subject to R

feedback capacitor.

Low-Cost, High-Slew-Rate,

Rail-to-Rail I/O Op Amps in SC70

6

_______________________________________________________________________________________

Figure 1a. Output Source Current vs. Temperature

Figure 1b. Output Sink Current vs. Temperature

0

1

2

3

4

5

6

-40

-10

-25

5

20 35 50 65 80

125

95 110

TEMPERATURE (°C)

0

1

2

3

4

5

6

7

8

9

-40

-10

-25

5

20 35

65

50

80

110

95

125

TEMPERATURE (°C)

Figure 2. Inverting and Noninverting Amplifier with Feedback

Compensation

MAX4490

R

R

MAX4490

R

R

INVERTING

NONINVERTING