REV. C

AD744

–9–

Figures 31 and 32.

Max

Slew

–3 dB

R1

R2

Gain

Gain

Rate

Bandwidth

( )( )

Follower

Inverter

(pF)

(pF)

(pF)

(V/ s)

(MHz)

4.99 k

4.99 k

2

1

50

0

7

75

2.5

1

4.99 k

4.99 k

2

1

150

5

7

37

4.99 k

4.99 k

2

1

1000

20

–

14

1.2

4.99 k

4.99 k

2

1

>2000

25

–

12.5

2

1.0

499

Ω

4.99 k

11

10

270

0

–

75

1.2

499

Ω

4.99 k

11

10

390

2

–

50

0.85

499

Ω

4.99 k

11

10

1000

5

–

37

2

0.60

NOTES

µs, equal to 0.025

µF. Slew rate is specified into rated max C

specified with a 50 pF. load.

AD744

1 F

0.1 F

1 F

0.1 F

OPTIONAL

R2*

R1*

*SEE TABLE II

Figure 32. AD744 Connected as an Inverting Amplifier

Operating at Gains of 1 or Greater

Using Decompensation to Extend the Gain Bandwidth

Product

When the AD744 is used in applications where the closed-loop

gain is greater than 10, gain bandwidth product may be enhanced

by connecting a small capacitor between Pins 1 and 5 (Figure

33). At low frequencies, this capacitor cancels the effects of the

ompensating the amplifier.

Due to manufacturing variations in the value of the internal

optimized for the desired gain by using a 2 to 10 pF trimmer

capacitor rather than using a fixed value.

\

AD744

1 F

0.1 F

1 F

0.1 F

NOT CONNECTED

R2*

R1*

2 – 10pF

*SEE TABLE III

Figure 33. Using the Decompensation Connection to

Extend Gain Bandwidth

Table III. Performance Summary for the Circuit of Figure 33

R1

R2

Gain

Gain

–3 dB

Gain/BW

( )( )

Follower

Inverter

Bandwidth

Product

1 k

10 k

11

10

2.5 MHz

25 MHz

100

10 k

101

100

760 kHz

76 MHz

100

100 k

1001

1000

225 kHz

225 MHz