REV. G

–12–

AD829

Figure 11. Large Signal Pulse Response of Inverting

Amplifier Using Current Feedback Compensation,

Ω, R1 = 1 kΩ

FREQUENCY (Hz)

–15

100k

100M

1M

10M

–12

–9

–6

–3

0

3

6

9

12

15

–3dB @ 8.2MHz

–3dB @ 10.2MHz

–3dB @ 9.6MHz

GAIN = –2

GAIN = –4

GAIN = –1

Figure 12. Closed-Loop Gain vs. Frequency for the Circuit

of Figure 9

Figure 13 is an oscilloscope photo of the pulse response of a

unity gain inverter that has been configured to provide a small

signal bandwidth of 53 MHz and a subsequent slew rate of

180 V/

µs; resistor R

Ω and capacitor C

shows the excellent pulse response as a unity gain inverter, this

Figures 15 and 16 show the closed-loop frequency response of the

AD829 for different closed-loop gains and different supply voltages.

If a noninverting amplifier configuration using current feedback

compensation is needed, the circuit of Figure 17 is recommended.

This circuit provides a slew rate twice that of the shunt com-

pensated noninverting amplifier of Figure 18 at the expense of

gain flatness. Nonetheless, this circuit delivers 95 MHz bandwidth

with

±1 dB flatness into a back terminated cable, with a differ-

ential gain error of only 0.01% and a differential phase error of

only 0.015

° at 4.43 MHz.

Figure 13. Large Signal Pulse Response of the Inverting

Amplifier Using Current Feedback Compensation,

Ω, R1 = 3 kΩ

Figure 14. Small Signal Pulse Response of Inverting

Amplifier Using Current Feedback Compensation,

Ω, R1 = 1 kΩ

FREQUENCY (MHz)

–15

100

110

–12

–9

–6

–3

0

3

6

9

12

15

GAIN = –2

GAIN = –4

GAIN = –1

Figure 15. Closed-Loop Frequency Response for the

Inverting Amplifier Using Current Feedback Compensation