ADA4000-1/ADA4000-2/ADA4000-4

Rev. 0 | Page 11 of 16

)

SETTLING TIME

Settling time is the amount of time it takes the amplifier output

to reach and remain within a percentage of its final value. This

is an important parameter in data acquisition systems. Because

most bipolar DAC converters have current output, an external

op amp is required to convert the current to voltage. Therefore,

the amplifier settling time plays a role in the total settling time

of the output signal. A good approximation for the total settling

time is

() (

2

2

AMP

t

DAC

t

Total

t

S

S

S

+

=

The ADA4000-1/ADA4000-2/ADA4000-4 settle to within 0.1%

of their final value in less than 1.2 μs. The settling time has been

tested by using the configuration circuit in Figure 34.

The input signal is a 10 V pulse and the output is the error

signal for the settling time shown in Figure 33.

200ns/DIV

200mV/DIV

5V/DIV

Figure 33. Settling Time Measurement Using the False Summing Node Method

ADA4000-1

V+

V–

+15V

–15V

10V p-p

3

2

1

10kΩ

10kΩ

10kΩ

AD828

V+

V–

+15V

–15V

20kΩ

1kΩ

8

4

10kΩ

V1

0

Figure 34. Settling Time Test Circuit