AD9632 datasheet(16/20 Pages) AD

16 / 20 page

AD9631/AD9632

Data Sheet

Rev. D | Page 16 of 20

PULSE RESPONSE

Unlike a traditional voltage feedback amplifier, where the slew

speed is dictated by its front end dc quiescent current and gain

bandwidth product, the AD9631/AD9632 provide on-demand

current that increases proportionally to the input step signal

amplitude. This results in slew rates (1300 V/µs) comparable

to wideband current feedback designs. This, combined with

relatively low input noise current (2.0 pA/√Hz), gives the

AD9631/AD9632 the best attributes of both voltage and

current feedback amplifiers.

LARGE SIGNAL PERFORMANCE

The outstanding large signal operation of the AD9631 and

AD9632 is due to a unique, proprietary design architecture. To

maintain this level of performance, the maximum 550 V × MHz

product must be observed (for example, @ 100 MHz, VOUT ≤

5.5 V p-p).

POWER SUPPLY BYPASSING

Adequate power supply bypassing can be critical when optimiz-

ing the performance of a high frequency circuit. Inductance in

the power supply leads can form resonant circuits that produce

peaking in the amplifier’s response. In addition, if large current

transients must be delivered to the load, then bypass capacitors

(typically greater than 1 µF) will be required to provide the best

settling time and lowest distortion. A parallel combination of at

least 4.7 µF, and between 0.1 µF and 0.01 µF, is recommended.

Some brands of electrolytic capacitors will require a small series

damping resistor ≈4.7 Ω for optimum results.

DRIVING CAPACITIVE LOADS

The AD9631/AD9632 were designed primarily to drive non-

reactive loads. If driving loads with a capacitive component is

desired, the best frequency response is obtained by the addition

of a small series resistance as shown in Figure 62. Figure 63

shows the optimum value for RSERIES vs. capacitive load. It is

worth noting that the frequency response of the circuit when

driving large capacitive loads will be dominated by the passive

roll-off of RSERIES and CL.

Figure 62. Driving Capacitive Loads

Figure 63. Recommended RSERIES vs. Capacitive Load

RSERIES

RIN

1kΩ

AD9631/

AD9632

CL (pF)

AD9632 датащи(PDF) 16 Page - Analog Devices

AD9632 датащи(HTML) 16 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

датащи скачать

ссылки URL