ISL60002_06 Datasheet, PDF (29/31 Pages) Intersil Corporation – Precision Low Power FGA™ Voltage References

ISL60002
400
350
300
250
200
150
100
50
0
1
CL = 0
CL = 0.001µF
CL = 0.1µF
CL = 0.01µF & 10µF + 2kΩ
10
100
1k
10k
FIGURE 100. NOISE REDUCTION
100k
V_IN = 3.0V
0.1µF
10µF
V_IN
V_O
ISL60002
GND
0.01µF
2kΩ
10µF
FIGURE 101.
Turn-On Time
The ISL60002 devices have ultra-low supply current and
thus the time to bias up internal circuitry to final values will
be longer than with higher power references. Normal turn-on
time is typically 7ms. This is shown in Figure 102. Since
devices can vary in supply current down to >300nA, turn-on
time can last up to about 12ms. Care should be taken in
system design to include this delay before measurements or
conversions are started.
3.5
3.0
V_IN
2.5
2.0
580nA
1.5
1.0
280nA
380nA
0.5
0
-1
1
3
5
7
TIME (ms)
9
11
3.5
V_IN
3.0
2.5
2.0
580nA
280nA
1.5
1.0
380nA
0.5
0
-1
1
3
5
7
TIME (ms)
9
11
FIGURE 102. TURN-ON TIME
Temperature Coefficient
The limits stated for temperature coefficient (tempco) are
governed by the method of measurement. The
overwhelming standard for specifying the temperature drift of
a reference is to measure the reference voltage at two
temperatures, take the total variation, (V_HIGH – V_LOW), and
divide by the temperature extremes of measurement
(T_HIGH – T_LOW). The result is divided by the nominal
reference voltage (at T = 25°C) and multiplied by 10⁶ to yield
ppm/°C. This is the “Box” method for specifying temperature
coefficient.
29
FN8082.7
August 1, 2006