ADA4000-1_07 AD [Analog Devices], ADA4000-1_07 Datasheet - Page 11

• Manufacturer Part Number: ADA4000-1_07
• Description: Low Cost, Precision JFET Input Operational Amplifiers
• Manufacturer: AD [Analog Devices]

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
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.
t
S
Total
=
(
t
S
DAC
10V p-p
) (
2
+
t
S
AMP
V1
)
10kΩ
2
0
3
2
ADA4000-1
+15V
–15V
10kΩ
V+
V–
Figure 34. Settling Time Test Circuit
Rev. 0 | Page 11 of 16
1
10kΩ
10kΩ
The input signal is a 10 V pulse and the output is the error
signal for the settling time shown in Figure 33.
Figure 33. Settling Time Measurement Using the False Summing Node Method
1kΩ
ADA4000-1/ADA4000-2/ADA4000-4
AD828
+15V
–15V
V+
V–
8
4
20kΩ
200ns/DIV
V
OUT
200mV/DIV
5V/DIV