TLV2217

LOW DROPOUT FIXEDVOLTAGE REGULATORS

SLVS067K − MARCH 1992 − REVISED AUGUST 2004

5

POST OFFICE BOX 655303

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

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

∆IL

∆VL

∆VL = ESR × ∆IL

Not Recommended

Potential Instability

CL = 22 µF

CI = 0.1 µF

TJ = 25°C

Maximum

ESR Boundary

Applied Load

Current

Load

Voltage

IL − Load Current − A

Minimum

ESR Boundary

10

µF

TLV2217

STABILITY

vs

ESR

Figure 2

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

VO = 3.3 V

22

µF

3.8 V

0.1

µF

TLV2217-33

INPUT

OUTPUT

Figure 3

GND