REV. D

AD8610/AD8620

–11–

TIME – 400ns/DIV

13V

G = –1

SR = 54V/ s

Figure 9. (+SR) of AD8610/AD8620 in Unity Gain of –1

TIME – 400ns/DIV

13V

G = –1

SR = 42.1V/ s

Figure 10. (+SR) of OPA627 in Unity Gain of –1

TIME – 400ns/DIV

13V

G = –1

SR = 54V/ s

Figure 11. (–SR) of AD8610/AD8620 in Unity Gain of –1

TIME – 400ns/DIV

13V

G = –1

SR = 56V/ s

Figure 12. (–SR) of OPA627 in Unity Gain of –1

The AD8610 has a very fast slew rate of 60 V/

µs even when config-

ured in a noninverting gain of +1. This is the toughest condition to

impose on any amplifier since the input common-mode capacitance

of the amplifier generally makes its SR appear worse. The slew

rate of an amplifier varies according to the voltage difference

between its two inputs. To observe the maximum SR as specified

in the AD8610 data sheet, a difference voltage of about 2 V between

the inputs must be ensured. This will be required for virtually any

JFET op amp so that one side of the op amp input circuit is com-

pletely off, maximizing the current available to charge and discharge

the internal compensation capacitance. Lower differential

drive voltages will produce lower slew rate readings. A JFET-

input op amp with a slew rate of 60 V/

µs at unity gain with

µs if it is operated at a gain of

The slew rate of the AD8610/AD8620 is double that of the OPA627

when configured in a unity gain of +1 (see Figures 13 and 14).

TIME – 400ns/DIV

13V

G = +1

SR = 85V/ s

Figure 13. (+SR) of AD8610/AD8620 in Unity Gain of +1