Datasheet

9
LT1461
APPLICATIO S I FOR ATIO
WUUU
Examples shown in this Applications section use the
LT1461-2.5. The response of other voltage options can
be estimated by proper scaling.
Bypass and Load Capacitors
The LT1461 family requires a capacitor on the input and
on the output for stability. The capacitor on the input is a
supply bypass capacitor and if the bypass capacitors
from other components are close (within 2 inches) they
*SEE APPLICATIONS INFORMATION FOR DETAILED EXPLANATION OF LONG-TERM DRIFT
Long-Term Drift (Number of Data Points Reduced at 650 Hours)*
TYPICAL PERFOR A CE CHARACTERISTICS
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Characteristic curves are similar for most LT1461s.
Curves from the LT1461-2.5 and the LT1461-5 represent the extremes of the voltage options. Characteristic curves for other output
voltages fall between these curves and can be estimated based on their output.
HOURS
–50
ppm
50
150
250
0
100
200
400 800 1200 1600
1461 G15
2000
200 600 1000 1400
1800
0
LT1461S8
3 TYPICAL PARTS SOLDERED ONTO PCB
T
A
= 30°C
V
OUT
200mV/DIV
1461 F02
Figure 2. 50mA Load Step with C
L
= 2µF
I
OUT
50mA/DIV
0mA
1mA
I
OUT
1mA/DIV
V
OUT
20mV/DIV
1461 F01
Figure 1. 1mA Load Step with C
L
= 1µF
should be sufficient. The output capacitor acts as fre-
quency compensation for the reference and cannot be
omitted. For light loads ≤1mA, a 1µF nonpolar output
capacitor is usually adequate, but for higher loads (up to
75mA), the output capacitor should be 2µF or greater.
Figures 1 and 2 show the transient response to a 1mA
load step with a 1µF output capacitor and a 50mA load
step with a 2µF output capacitor.