AD588
Data Sheet
Output turn-on time is modified when an external noise
TURN-ON TIME
reduction capacitor is used. When present, this capacitor
presents an additional load to the internal Zener diode current
source, resulting in a somewhat longer turn-on time. In the case
of a 1 µF capacitor, the initial turn-on time is approximately
60 ms (see Figure 11).
Upon application of power (cold start), the time required for
the output voltage to reach its final value within a specified
error band is the turn-on settling time. Two components
normally associated with this are the time for active circuits to
settle and the time for thermal gradients on the chip to stabilize.
Note that if the noise reduction feature is used in the 5 V
configuration, a 39 kΩ resistor between Pin 6 and Pin 2 is
required for proper startup.
Figure 9 and Figure 10 show the turn-on characteristics of the
AD588. The settling is about 600 µs. Note the absence of any
thermal tails when the horizontal scale is expanded to 2 ms/cm
in Figure 10.
+V
S
+V
S
–V
S
V
OUT
V
OUT
Figure 11. Turn-On with CN = 1 µF
Figure 9. Electrical Turn-On
TEMPERATURE PERFORMANCE
The AD588 is designed for precision reference applications where
temperature performance is critical. Extensive temperature testing
ensures that the device’s high level of performance is maintained
over the operating temperature range.
+V
S
Figure 12 shows typical output temperature drift for the AD588BQ
and illustrates the test methodology. The box in Figure 12 is
bounded on the sides by the operating temperature extremes
and on top and bottom by the maximum and minimum output
voltages measured over the operating temperature range. The
slope of the diagonal drawn from the lower left corner of the
box determines the performance grade of the device.
V
OUT
V
– V
MIN
Figure 10. Extended Time Scale Turn-On
MAX
SLOPE = T.C. =
–4
(T
– T
) × 10 × 1
MIN
MAX
10.0013V – 10.00025V
–4
(85°C – –25°C) × 10 × 10
10.002
= 0.95ppm/°C
V
MAX
10.001
V
MIN
10.000
–35 –15
5
25 45 65 85
TEMPERATURE (°C)
V
V
MAX
MIN
Figure 12. Typical AD588BQ Temperature Drift
Rev. M | Page 10 of 20
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