Datasheet

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SLVS067L − MARCH 1992 − REVISED APRIL 2005
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
COMPENSATION-CAPACITOR SELECTION INFORMATION
The TLV2217 is a low-dropout regulator. This means that the capacitance loading is important to the performance
of the regulator because it is a vital part of the control loop. The capacitor value and the equivalent series resistance
(ESR) both affect the control loop and must be defined for the load range and the temperature range. Figures 1 and 2
can be used to establish the capacitance value and ESR range for the best regulator performance.
TLV2217
ESR OF OUTPUT CAPACITOR
vs
LOAD CURRENT
Figure 1
ESR − Equivalent Series Resistance −
1
0.8
0.4
0.2
0
1.8
0.6
0 0.1 0.2 0.3
1.4
1.2
1.6
3
0.4 0.5
2
2.2
2.4
2.6
2.8
Ω
∆I
L
∆V
L
∆V
L
= ESR × ∆I
L
Not Recommended
Potential Instability
C
L
= 22 µF
C
I
= 0.1 µF
T
J
= 25°C
Maximum
ESR Boundary
Applied Load
Current
Load
Voltage
I
L
− Load Current − A
Minimum
ESR Boundary
10 µF
TLV2217
STABILITY
vs
ESR
Figure 2
C
L
0.015
0.01
0
0 0.5 1 1.5 2 3 4
0.025
0.035
1/ESR
0.04
4.5 5
0.005
0.03
0.02
22 µF
1000 µF
2.5 3.5
100 mF
200 µF
400 µF
Not Recommended
Potential Instability
Recommended Minimum ESR
Region of
Best Stability
typical application schematic
V
O
= 3.3 V
22 µF
3.8 V
0.1 µF
TLV2217-33
INPUT OUTPUT
Figure 3
GND