Datasheet

AD586
Rev. G | Page 8 of 16
00529-007
C
N
= 1µF
NO C
N
50µS
200µV
Figure 8. Effect of 1 µF Noise Reduction Capacitor on Broadband Noise
TURN-ON TIME
Upon application of power (cold start), the time required for
the output voltage to reach its final value within a specified
error band is defined as the turn-on settling time. Two compo-
nents normally associated with this are the time for the active
circuits to settle, and the time for the thermal gradients on the
chip to stabilize. Figure 9, Figure 10, and Figure 11 show the
turn-on characteristics of the AD586. It shows the settling to be
about 60 µs to 0.01%. Note the absence of any thermal tails
when the horizontal scale is expanded to l ms/cm in Figure 10.
Output turn-on time is modified when an external noise reduc-
tion capacitor is used. When present, this capacitor acts as an
additional load to the current source of the internal Zener
diode, resulting in a somewhat longer turn-on time. In the case
of a 1 µF capacitor, the initial turn-on time is approximately
400 ms to 0.01% (see Figure 11).
00529-008
V
IN
V
OUT
10V
1mV
20µS
Figure 9. Electrical Turn-On
00529-009
V
IN
V
OUT
10V 5V
1mS
Figure 10. Extended Time Scale
00529-010
V
IN
V
OUT
10V
1mV 100mS
Figure 11. Turn-On with 1µF C
N
Characteristics
DYNAMIC PERFORMANCE
The output buffer amplifier is designed to provide the AD586
with static and dynamic load regulation superior to less com-
plete references.
Many ADCs and DACs present transient current loads to the
reference, and poor reference response can degrade the per-
formance of the converter.
Figure 12, Figure 13, and Figure 14 display the characteristics of
the AD586 output amplifier driving a 0 mA to 10 mA load.
AD586
V
L
5V
0V
V
OUT
500Ω
3.5V
00529-011
Figure 12. Transient Load Test Circuit