January 1999 TOKO, Inc.

Page 11

TK715xx

In general, the capacitor should be at least 1

µF and be rated for the actual ambient operating temperature range. The

table below shows typical characteristics for several types and values of capacitance. Please note that the ESR varies

widely depending upon manufacturer, type, size, and material.

BOARD LAYOUT

Copper pattern should be as large as possible. Power dissipation is 350 mW for SOT-23-3. A low ESR capacitor is

recommended. For low temperature operation, select a capacitor with a low ESR at the lowest operating temperature

to prevent oscillation, degradation of ripple rejection and increase in noise. The minimum recommended capacitance is

2.2

µF.

The internal reverse bias protection eliminates the requirement for a reverse voltage protection diode. This saves both

cost and board space.

SOT-23-3 BOARD LAYOUT

Note: ESR is measured at 10 kHz.

ESR

Capacitance

Aluminum

Capacitor

Tantalum

Capacitor

Ceramic

Capacitor

1.0

µF

2.4

Ω

2.3

Ω

0.140

Ω

2.2

µF

2.0

Ω

1.9

Ω

0.059

Ω

3.3

µF

4.6

Ω

1.0

Ω

0.049

Ω

10

µF

1.4

Ω

0.5

Ω

0.025

Ω

APPLICATION INFORMATION (CONT.)

+

+

VIN

VOUT

GND